UNIVERSITY OF CALIFORNIA PUBLICATIONS IN AGRICULTURAL SCIENCES Vol. 1, No. 5, pp. 63-126 October 23, 1913 STUDIES UPON INFLUENCES AFFECTING THE PROTEIN CONTENT OF WHEAT BY G. W. SHAW In 1905 the Merchants' Exchange of San Francisco, the State Board of Trade, the Sacramento Valley Development Associ- ation, and the more prominent millers and grain dealers of California called the attention of the Agricultural Department of the University to the fact that the milling trade found it necessary to import many hundred tons of wheat per year to maintain the quality of California flour owing to the low gluten content of the wheat grown in the state. With the view of ascertaining the causes of such an undesir- able condition, investigations were begun under an appropriation made by the Legislature at the session of 1906 (Senate Bill no. 10, entitled ''An Act to provide for the improvement of cereal crops of California and appropriating money therefor"). The investigations are still under way, the bill having been re-enacted at the legislative session of 1908 and again in 1910. The chief points for study in these investigations are: (1) To determine the effect of changes of environment upon the growth of cereals, particularly as regards the coinposition of the wheat kernel and with special reference to the causes of the production of a low protein content; (2) to discover o» produce such wheat as will yield the largest profit per acre for the farmer, and will supply the millers with wheat of superior quality; (3) to conduct similar experiments with oats, barley, and other cereals as may he desirable; (4) to determine the effectiveness of various methods of culture as affecting the production of cereals. 64 University of California Publications in Agricultural Sciences [Vol. 1 The nature of this work is such that no permanent results can be secured from one or two seasons' operations. The element of time is an all-essential one for the solution of such problems. This would be true even though the problem was merely the development of wheats giving higher yields than those now being gro^^^l in the State, but ivith the introduction of the problem of increasing the ghden content, the element of time is even of greater importance. With this in view, the experiments were so planned that while the final results could not be expected for several years, it was possible to obtain data of importance bearing upon the entire question of cereal culture each year, material progress thus being assured. As early as 1882 Clifford Richardson called attention to the fact that wheats from the Pacific Coast were relatively low in their protein content, and numerous analyses of California grown wheats made at the California Agricultural Experiment Station under the direction of Dr. E. W. Hilgard, in the earlier years, also showed the same condition to exist. That this condition exists is undoubtedly true, whatever the causes may be. To bear witness to the fact the following sum- mary is given of analyses of white wheats grown in several different states, as compared with the anal3^ses of 149 samples of wheats of the same class grown in California in the same years. For the sake of comparison also the average results obtained from the analysis of 49 hard winter wheats grown in Kansas the same season are included, as well as those of three soft white wheats grown in Kansas from seed originally obtained from the state of Washington. Table Showing the Protein Content of White Wheats Grown in Different States in the Same Season Number Total State of samples protein Dri/ basis California 149 9.77 Idaho 46 10.88 Nevada 34 16.18 Montana 6 14.24 Utah 10 15.20 Washington 177 1 2.98 Kansas (liard winter) 49 13.2.5 Kansas (white wheats) * 3 10.57 Grown in Kansas from seed secured from the State of Washington. 1913] Shaiv : Studies on Infmences Afecting Protein Content of Wheat 65 In practically all of the former studies of this subject the plan has been to transfer the seed from one point to another and thus change the environmental conditions, and from the results so secured to attempt to draw general conclusions. Under such conditions, changes, not merely in environment, but also in soil, were accomplished, thus introducing too many variables. In the experiments here recorded two general methods have been followed: {a) the production of numerous varieties of wheat in the field on a small area of uniform soil and varying other con- dition of growth than the soil, and (5) growing wheat from the same seed under the same conditions on soils of widely different origin placed under the same cultural and climatic influences. The large and important question involved is the cause or causes of the relatively low gluten content of wheat grown under Cali- fornia conditions. In this connection, it is particularly desirable to know whether or not such tendency to change as exists is constant; whether it is due to some climatic influence, the time of cutting, the time of seeding, the bleaching action of the sun, the efl^ect of early and late application of moisture, the effect of cold nights, of varying amounts of sunshine during the rip- ening period, or to some induced or inherent condition of the soil. The work which we have conducted has aimed at the solu- tion of all of the questions just mentioned and consisted of several parts each of which dealt with one of, the questions involved. Variation in the Protein Content of Wheat Seasonal Variation. — It has been observed that from season to season there is a marked variation in the protein content of wheat even though grown upon the same soil, a seeming indi- cation that the seasonal factor is considerably greater than the soil factor in protein formation. This may be shown from a number of samples grown during the course of the experiments, some of which are given below. These wheats have been grown each year on the same soil and under the same cultural conditions at the University Farm at Davis, California. University of California Publications in Agricultural Sciences [Vol. 1 Total Protein in Dry Matter 1906 1907 1908 1909 1910 1911 1912 Kubanka 9.68 9.90 14.71 14.30 14.87 10.60 14.93 Crimean 10.38 11.38 11.75 13.27 12.18 10.60 12.11 Little Club Av. of 5 plats 10.29 9.78 9.98 13.00 That the quantity of available nitrogen in the soil has com- paratively little bearing, if any, beyond its necessity in sufficient quantity to insure the normal growth of the plants, is indicated on a series of fertilizer plats of very uniform land, discussed further on in this paper. The seasonal effect is apparent, how- ever, from the check plats in the same series. Varietal Variation. — Variation in protein content occurs be- tween different varieties of wheat, even though the strain be a pure one and the soil conditions under which they are grown be the same. The analyses given below are from plants of pure strain grown during the course of breeding experiments in cent- gener plats under just as nearly the same conditions as it is possible to secure in the field. The soil was uniform and the plants were 4 inches apart each way and seeded at a uniform depth of 2 inches. Grown at Davis, 1908 Little Club Number of samples 163 Per cent protein 11.83 Propo Fretes 38 111 12.20 13.46 Grown at Ceres, 1908 Chul Number of samples 53 Per cent protein 14.98 Kharkov 50 13.95 White Australian 70 14.69 In addition to the varietal variations here shown, the above figures are of interest in showing that Kharkov, which is a hard winter wheat, when grown under California conditions in the same season does not carry a higher percent of protein than a good quality of the White Australian belonging to the white wheat class. 1913] Shaw: Studies on Tnfuences Affecting Protein Content of Wheat 67 y aviation in Individual Plants. — That there is a wide dif- ference in the ability of individual plants to elaborate protein in the grain is shown from the analysis of a number of varieties grown under like conditions on the same character of soils. These plants were all grown in the same season in centgener plats, the plants being four (4) inches apart each way, and seeded at uni- form depth by means of a centgener planter. The outside rows were all cut away at harvest and discarded, so that none of the plants shown here represent outside rows, but all had a uniform feeding area on uniform land. In each of the lots shown in Table 1 it will be noted that there is a great variation between individual plants even when grown under exactly the same climatic and cultural conditions. The vari- ation in individual plants of the variety White Australian ranged from a minimum of 9.06 to 15.31 per cent total protein, or a variation of 6.25 per cent within 25 plants, and the range in Little Club is even greater, being from 7.12 to 15.22. Such evidence as that presented above would seem to throw the main factors determining the protein content of wheats, and inferentially other grains, externally, primarily upon some cli- matic influence, and secondarily upon the internal factors of variety and individuality of the plant itself. It seems certain that the individuality of the wheat plant is just as potent in determining the protein content of the grain as is the indiv- iduality of the dairy cow in determining the fat content of her milk and that it is just as impossible to feed protein into wheat by increasing the available nitrogen of the soil as it is to feed butter-fat into a cow's milk. Following these general considerations of some of the external and internal factors bearing upon the question of protein vari- ation, attention is turned to more restricted phases of the problem. 68 University of California Publications in Agricultural Sciences [Vol. QC Ci O ^ ,-. q CO o (^^CiTt^cooiOOO(^^ l-O O LO O t- 00 1— I rH L^ -— OOOOOOoOCiO CO -^ CO CO O r-^' O Ph - C0^00'*COCQ'S0lOO5L-^lO0irhl>O0i. t- Ci rJH ^^ CO CO '^ Ci 00 r-i'i— •C-i'-irHr-ir-ir-ii-^r-i^i'-^T-JCvlC^icvio-irHr-ii— 1 O y: c r. 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The central idea was that if there really existed a strong tendency toward the development of a distinctl}^ starchy nature, under the conditions which here obtain, not only would the progeny of perfectly typical glutenous kernels show a considerable number of more or less starchy kernels and a lower protein (gluten) content, but spotted kernels would show a similar change in their progeny ; and the entirely changed kernels, carrying 100 per cent of starchy kernels in the original, would show a still lower percent of typical kernels and a very low protein content in the progenj^ remaining, in fact, essentially starchy. The plan of the experiment which extended over the seasons of 1906-08, inclusive, was to grow a number of varieties of wheat at several points in the state, the physical and chemical con- dition of the originals used being first determined, and to follow the changes in the progeny in each instance during the season and the total period of the trials. The experiments were conducted in the fields at Modesto, Ceres, and Tulare as typical of San Joaquin Valley conditions, and at Yuba City and Davis as representative of Sacramento Valley conditions. In order to follow better such changes as occurred, by the eye as well as by analysis, such varieties of wheat were selected as had typical kernels of distinctive ap- pearance. THE NITROGEN OF TYPICAL vs. SPOTTED WHEAT KERNELS OF THE SAME VARIETY At the outset a number of varieties of wheat were hand- separated into three primary lots or groups, based upon the physical appearance of the kernels, as follows : Group I, consisting entirely of perfectly typical (glutenous) kernels ; Group II, consisting of kernels of the same varieties of wheat 70 University of California Publications in Agricultural Sciences [Vol. 1 which were of an entirely starchy character, showing no typical kernels whatsoever; Group III, consisting of kernels of the same varieties of an intermediate appearance upon which the percentage of typical kernels was determined in each case. Each of these lots was subjected to a determination of the nitrogen content in order to ascertain whether this dis- tinctive appearance of the kernels was a fair indication of their nitrogen content. The results are subtended: Nitrogen Content (Dry Basis) Sample no. 1 Typical kernels 1.75 More or less starchy kernels 1.45 Sample no. 2 1.75 1.54 Sample no. 3 1.67 1.54 Sample no. 4 1.85 1.57 Sample no. 5 1.98 1.74 Sample no. 6 2.13 "1.78 Sample no. 7 2.09 1.73 Sample no. 8 2.03 1.74 Sample no. 9 1.98 1.52 Sample no. 10 2.02 1.90 Sample no. 11 2.12 1.90 Sample no. 12 2.27 2.08 Sample no. 13 1.82 1.68 Sample no. 14 2.03 1.68 Sample no. 15 2.33 1.83 Sample no. 16 1.83 1.62 Average 1.97 1.69 These results seem to show that the physical appearance of the grain may, in general at least, be taken as a fair index of its relative gluten or protein content. Each of the above described groups was drill-seeded in a num})er of rows in a uniform manner and under uniform soil conditions and given the same cultural treatment. The results of the experiments in 1906 are tabulated below: 1913] Shaw : Studies on Influences Affecting Protein Content of Wheat cc O Cvl O Cvj O i-i O Cvl CI O] Oi CO **< (M* c- ^ Ci CM CM P rn" CO COt— lOOQOCDOOlOOOi^^COOOPTtlGO I— I ^ CD O CO rtj I— I O GO O CCJ rH r^ CD CM 50 Cv] O CO Oi CO* T-i O rA rA d rA aO rA oi rA oi <^1 th" Cvi i-H 1— I >— I iH I— I H.^ CM CM CDOSCOCMGOCOCDO Oi »0 O Tt Oi i-J Ci !>; n CM* rH cm" cm* rA CM r-i r-i CM* r-i rA CM* — i r^" CM 'O Tfl CD SOiGOrHt^iraiOt^CDt^CO -iS Oi Oi OI 00 TtH Oi CM Oi CD rH .2 Ci* d d o Oi" d o" r-i d r-i r-i r-i r-t ^ '^ '^iiS^'^GMCDCDlOlO SS^S"^ '^ <^ "-I "^ <^ 3^C£CMCMCMCMCMrH OilOOOOrtHOOiOCDCDr-llOCD r^r^r^cMr^r^OkO'*^r^^:-r^o CMCMCMCOCOCOCOCMCMCMrHCOCO "S-^ O Oi o TtHOOiOrHOCDOOOCMCOOiCMCOOCO c o 00 d Oi* d CD d rjH* d r-i d 00 d cm" o6 t-^ CO lo d oi ^v /^^ /^ /^s, ,^rs /-v^ f-^s '*4>i y'^^ ^"^ ('T\ t-. 0 t-^ \o t- 72 University of California Fublications in Agricultural Sciences [Vol. 1 t o cq o (M o Tt< o oq eg' G\i CO* cm" cm' c^i cd oj I— l(MO500O5O^'^OiiX)aiCM r-{^ r^ C^ (M_ Ci O Oi iH O (M ^ c\i (m' od cvi i-H cvi rA od CO o o IX) Tti _ ^^ '^ '^ O lO cvi cvi o t^ o eg O L-~ O L-- 00 L- Oi 00 O rH rH rH O O eg eq r-i eg' r-i' rA tA tA rA eg cq' eg' eg' eg' eg* eg .ScOrHt-TtlrHegOOOOO 0^ Oi Oi e-i CO '^ L^ c-1 CO g rH o o o oi oi rH o oi eg t- O rH CO o o o^ CO Oi '^ O CO o O l-O GO eg L^ rH o oo' o eg rH* eg* lO 00 rH* d SiOCgrHCgCOOlOrHCOTtHTtHt^Oit^egt^OrHlOCOCOOirHcO OI— tOiOOOO'^t^OOOt^Oi-^QOLOL^HHl^lOOi'-HOr^OOOOOO eg eg eg rH rH rH b Oi 5 Oi .|oi rHrHQOLOOil^Ot-rHC^lOiHHT-H^lOOOrHThl^t- rHCgeO'*t-e>3lOCOcOTt^^t-^COi— IL^COCOO^ ccot-coi>.koioocou:> 'c-OrHOOiCOOrHOrH sd.-'-cg'^cgrHeqcgcgcgeg O Tft coooooooqegooot^rHo rHCgcOOirHOCOCOOOOrHr-irH e^iegcocgcocoeqcgoq(>qcocococo CO d CO o O TjH o o * oi d CO o o o d eg* d COOCOL'---^CgOrHOiOit^ loOL^cocoiracococooit^ CO cocgcot-iooiooirat^ eg ^ eg f5 cq So t>> 'So t^ O J '-M 3 'S 9 'S O Hj o ^^ o o CO Sd :>. 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QJ o o q; a OJ O) o ^ -M +-. .'rH +-^ -t-i -M +-< ,(_1 4_, O r= rt o _b£ ii o o o f-l o o Uj K^ P CC i3 '^ C» m (/J 02 02 03 03 c3 0^ cS 03 >y piil ^ -Iri risj •^ C C a fl « c S rt rt rt 01 c3 rt " F^ ^ ^ ^ ^ ^ ■ r-i ■ r^ ^ ^ t^ t^ w w ,J3 ^ r^ P^ rd no no q; (U Oj w w w 03 03 > O riii o 03 C« ^' ^-' 4il a 03 OS 'bf) .9 'bfi rU rO rd r£3 03 oi o o ^ ^ 03 03 ,^3 QJ QJ OHHHHMMMMMMPQpq ;>^ -i ci -^ <1 -^ pCj ffl XOr^CO>OCOI~OiOOOQOQOODI;^OOrHC^)COrHr^1co -t< lO lO "O -t >0 lO lO CO CO CO CO CO I- I-- I- I- CO CO CO CO •,0 CO CO CO CD CO CO CO CO CO CO CO CO CO CO CO CO CO CO 00 OO 00 1913] Shaiv : Studies on Influences Afecting Protein Content of Wheat 73 DISCUSSION OF 1906 RESULTS Examination of the 1905-06 results shows that in physical appearance none of the seven originals carrying 100 per cent of typical kernels (Group I) maintained their perfection in their progeny — all showed some starchy kernels. The fact that those grown at Modesto show^ed 97.5 per cent of typical kernels in their progeny while those grown at Yuba City showed but 60.1 per cent ver}^ strongly suggests there must have been some local condition of either soil or climate which influenced this change. The average protein content of this group at Modesto and Yuba City decreased slightly, as did the percentage of typical kernels, showing 13.15 per cent total protein in the originals and 12.91 per cent in the progeny ; while at Yuba City the results were 12.52 per cent for the originals and 11.64 for the progeny. It will be noted also that the Modesto samples possessed some- what higher total protein as well as a larger percentage of typical kernels than did those grown at Yuba City. Under Group II at Modesto the progeny showed an average of 92.5 per cent of typical kernels from originals carrying abso- lutely none, and a comparative protein content of 10.97 per cent for the originals against 13.55 per cent for the progeny, or an increase of 2.58 per cent. Group III at Modesto carried an average of 40.7 per cent typical kernels in the originals and 96.6 per cent in the progeny, and a protein content of 12.55 and 13.11 respectively, a distinct increase in both respects. At Yuba City this group showed 62.9 and 69.5 per cent typical kernels in the originals and progeny respectively, and a protein content of 12.07 per cent against 11.92 per cent. Considered as a whole the results are expressed below: 74 University of California Fublications in Agricultural Sciences [Vol. 1 1906 Original Progeny Group I Number Per cent of samples typical in group kernels 100.0 81.5 Per cent total protein 12.74 12.78 Group II Group III Number Per cent Per cent Number Per cent Per cent of samples typical total of samples typical total in group kernels protein in group kernels protein 9 0.0 9 75. 10.58 12.50 55.6 78.5 12.23 12.32 General General average average Total per cent per cent number typical total 1906 of trials kernels protein Original 22 47.39 11.71 Progeny 22 78.2 12.54 . It is here shown that the average per cent of typical kernels in all the originals was 47.4 and in the progeny 78.2, and the protein content 11.71 per cent and 12.54 per cent respectively. It is perfectly evident from these figures that a wheat which consists of 100 per cent starchy kernels may, in a single season, revert to practically a perfect wheat, or to essentially the same average protein content for the season and region as a wheat groivn from perfectly glutenous kernels. Instances of this are particularly shown in samples no. 713 and no. 725. In the first the original consisted of 100 per cent of entirely starchy kernels and still produced 96.9 per cent of typical kernels in the progeny. In the second the same is shown to a somewhat smaller extent, the original carrying but 38.3 per cent typical kernels and still producing 97.9 per cent in the progeny. Other trials. — Trials were also made to determine the per- centage of typical seed in six varieties grown at Modesto from seed in which the percentage of typical kernels had been pre- viously determined, using 1000 kernels as a basis. These were also seeded in rows and were harvested in the hard dough stage. Counts were then made to determine the percentage of typical kernels in the progeny. The results appear below. 1913] Shaw : Studies on Influences Afecting Protein Content of Wheat 75 Name Per cent of typical kernels in original 1905 Per cent of typical kernels 1906 Fretes 94.0 95.2 Eedwinter 51.0 91.5 Hungarian 78.7 95.3 Kubanka 38.3 72.6 Koola 16.8 93.9 Marouani 43.2 93.1 Average 53.7 90.2 In each of the above cases the percentage of typical kernels increased in the 1906 crop over those of the 1905 crop and the average increase was from 53.7 to 90.2; it seems probable that some climatic or soil factor is more than likely to have been the cause of this change. This is particularly noticeable upon com- paring the results between the two stations. The above figures not only do not indicate that there was any strongly marked tendency toward lowering in quality, but, on the other hand, the general tendency seems to be upward for this season, particularly at Modesto. The Relation of Moisture. — It has been shown repeatedly by many investigators that the composition of plants varies considerably in different localities and in different seasons, and that the principal factor seems to be the climate instead of the soil, variations due to the latter being very slight if any. This feature will be presented more in detail later in this paper. While the relation of the water content of the soil at various stages of the plant growth to the protein content of wheats also forms a portion of these investi- gations for later presentation, it may be said that the Utah Station has conducted a number of experiments upon the effect of water upon the composition of plants, the method of which in each case has been to apply different amounts of water through- out the season on contiguous plats of uniform land. The fol- lowing selected results from the Utah experiments as affecting the protein content of the grain are of interest in this connection. 76 University of California Publications in Agricultural Sciences [Vol. 1 Inches of water applied 7.5 Protein content of Corn kernels 15.08 Oat kernels 20.79 Wheat kernels 26.72 15.0 13.48 17.29 19.99 37.3 12.52 15.49 16.99 It is shown here that as the amount of water is increased the protein content decreases. Others have also observed the effect of water upon the com- position of crops. Mayer, in Holland, showed that on a soil having 10 per cent of water the crop contained 10.6 per cent of protein, while on a soil with 30 per cent of water the protein percentage was only 6.6. Carleton calls attention to the fact that in the same varieties of wheat grown in the humid and arid regions of the United States the protein content was 11.94 per cent for the former and 14.4 per cent for the latter. Experi- ments conducted at Rothamstead, England, show that barley in a wet year contained 9.81 per cent of protein and in a dry year 12.99 per cent. The particular connection of this review of the observation of other workers to the results here presented lies in the dif- ferences in the results secured in 1906 between the Modesto and the Yuba City stations, at the former of which both the per- centage of typical kernels and the protein content in the progeny was distinctly higher than at the latter. These three factors are contrasted below. Inches Per cent Per cent rainfall tj'pical total Dec. 1-June 30 kernels protein Modesto 11.94 95.35 13.50 Yuba City 26.68 63.99 11.74 A very casual observation of these results shows that both the distinct difference in percentage of typical kernels and that between the protein content of the grain of the two stations was without doubt very strongly, if not entirely, determined by the difference in moisture which the grain received after planting. EXPERIMENTS OF 1907 In 1907 the experiment described above was continued at IModcsto and Yuba City, and also extended to Tulare. The results are stated below. 1913 ] Shmv : Studies on Influences Affecting Protein Content of Wheat ^ i-H GO O M CM Gi Oi < O-i r-i rH O O O t^ t- ^ O L^ , Ci O Oi CO (>J O O rH cm' ,_; C " (M Cvl 05 xtH Cv| Cvl i-HrHCX)r— (<;U O _J ^ OiOOOOCvlrHOCiClOJCOCOO CO O Oi O CO H.^ rH ^ ^ CJ CO CO r-H CO 00 ^ GC CJ r-i C<1 ,— I T— i r— ( D 00 T-i rH OJ CJ rH Ttl CO CO T-H Ci O ci rH c^i Tt^ rhi O LO 1-^ Tfi ^ CO O GO GO L-- O r-i' Cvi Ci r-i r-1 rH cj O O i-A r-i ci ^CSL-^CO^OOOL^"* g c: oi 00* ci i^ oi ^* ai oj »0 lO I— ( CD GO GO O t-. L-- lO O CO OO' O OO* r-i C-i ci rH CO t^ ^ 00 Ci ^ O CI OO O lO Ol CO CO O ci r-i o" ci ci ci a 00 -2 g' L- I- -^ L- C3 CO 05 lO rH T-H Cvl CO Cvl Oi CO Tfl L^ lO O I— I CO r-( rH C O) a; Oj O) a; ^ X ^ +j -i-j -M -M 4^ -M -(-i -^ -M -M o ^ u o o o o o c Q ^ ' Cw Ch p CC > ft m P O m Ul m m 02 C/2 c3 cS 03 c3 c3 C^ ►> |v ^ > c3 o o J^ p ft ^ riil r^ riri r^l ri^ Q >^ r^ 1% PI fl fl iq a VI rn no fl fl id d a fl fl -M +:> n rr( n1 rr^ cl ;h fH cu O (T! CS r1 cd ai o ^ M ^ M o o 6 -t-J g f^ • ^ 'S H T H s s o o Knb Velv Velv 'tSOlOt^OOGOCiCiCOCDlOlO^^COCOOOrHrHCJClCOCOrt^TtllOlO jjz; ^ CJ CJ Cl Cl Cl CM CJ CJ Cl Cl Cl CI Cl CO CO CO CO CO CO CO CO CO CO CO CO CDCiCiCiCiCiCiCiCiOiCiCiCiCiOiCiCiCiCiCiCiCiCiCiCiCi 78 University of California Publications in Agricultural Sciences [Vol. 1 Oq^(Mr-l(MO]CvI(M(Md eg cvi cd ; th Cvl ■ cvl (M 05 CO lO * CO O O lO rH Th Tt^ L^ lO 00 C\I lO iq '^ CO O CC Cv| glOrHi— iOrHOT-Hoii— ^t>-rHo6cOOicO^Cv|i— (C^ICOCOCOC: ^Cvli-^Oit^t^^OOOCCvjOilOTtHCOCOlOlO GOOL^QOCOaiCX)COi— ICOCOCvjCirHrHM-^ r-i C. O eg rJH o t- g CO oi Oi OS Oi 05 O QO O CO £rH rH rH 'Sfci)OOOOirHOairHOOCOQO +eococc>cDcot-ioooTha5--H ^i^ d ^- ^- ^' rA rA rA rA rA rA lOcgoiooot^QOcgTtHQOoot^OTtHr-io O CO rH t-. 00 OO rJH QO OO TjH Oi r-J 00 00 'sH ^^ o CO eg* o r-i CO r-i ci o o r-i eg 00 o oi o r-lrHrHrHrHrHi— I i-HCgr-lT— I r-l rH CgCgr-lCgCgcgr-lT-HCO^ fcJD rt .;:r r^-." .2r ^ .2r ^ .2r j3 f-i S 'f-i I2 '^ !3 '^H ^OhjO^ OS -T (73 .S .2 'So >^ "bJD ►^ 'So >-. o ^ o ^ o ^ Q Tl! 1^3 t3 nn! ■^ ^ TS nd QJ O) q; O) 0) O) P^ r^ Ph p^ Ph Ph i:^ ^ 02 J> P o 02 02 02 02 cc 02 02 2 fl fl c^ cS ri M M M C PI fl rt c3 rt ^ ,Q rD S ^ ;3 M tvd h> t3 'TS O OI 03 :3 13 s ^ 13 3 Sh ^ 2 > o 03 ,d M o C* o o ^ H W w »ra ^OrHco^»Or^|^(X)Qocoo:oiegcocoQOCiTt^ocoegTt^eg -t -ft »0 lO »0 IQ »0 CO »0 CO CO CO »0 CO CD CO CO I- CO QC I- Ci t^ t^ oo cocoes COC/DCOOOCOOOCOCOCOQOCOOOCOOOCOQOCOOOCOOOOCCO 1913] Shaiv : Studies on In^ucnces Ajfecting Protein Content of Wheat 79 rj « (M l^ Tt< I- tc (M Cv] i-i O C-1 "^ C] (M Ol CvJ CO O 'ti Tt< (M ,— I lO CO Ci t-; CO Oi l^ o r-i o CO ai ai o t-i" lO O LO o o CO ci o CO O C5 CM* H.-5 r^ --I ^ ^ t- Thi t-- Tt^ * gco-T-H;:;(>]-CM "So g 'So g 'So Ot-sOh-sO^Oi-sOi-sOt-sOi-s o 'T3 O S o ■TIJ -rJ T3 ^ ,—1 ^ O! a; QJ O Qi -(J -tj -*-i -M •+-> -M O o o o O Ph Oh .^ P^ cc 02 CC 02 H cc c. ° § -^ bJD be o o 'a; '3 "o "op c3 03 c-i-^'ticoaioocooo ^Jz; QOCJoociOiCi'^oco ^o^ COODCOOOCOOOCOOi 0^1 T^ Ttl CO o o CO o t- o CO Oi CO Oi CO Oi 4' 80 Vniversitif of California Publications in Agricultural Sciences [Vol. 1 Discussion of 1907 Results.- — Essentially the same results are shown here as in the preceding season. Of the seven (7) originals in Group I, all of the progeny dropped distinctly below the original standard, showing 55.99 per cent of typical kernels, while the eight samples in Group II, carrying distinctly starch kernels in the originals, all increased by about the same amount as the others dropped, the average per cent of typical kernels in the progeny being 55.2 per cent, or less than 0.7 per cent below those of Group I. In the group of typical kernel originals, only one out of seven increased in protein content, the average per cent in the originals being 12.79 against 11.20 per cent in the progeny, or a drop of 1.59 per cent. In Group II, consisting entirely of the distinctly starchy kernels, there was a universal increase in the typical kernels in the progeny, and three out of eight increased in protein content, the averages being 10.65 per cent for the originals and 11.02 per cent for the progeny. Group III showed 58.1 per cent typical kernels in the originals and 64.1 per cent in the progeny, an increase of 6 per cent; and 11.50 and 12.25 per cent total protein, respectively. Summarizing by groups as in the results of the preceding year, the figures appear as below : Group I Group II Group III 1 1907 Number in group Per cent typical kernels Per cent total protein Number in group Per cent typical kernels Per cent total protein Number in group Per cent typical kernels Per cent , total 4 protein Original . .... 7 100.0 12.79 8 0.0 10.65 18 58.10 11.50 Progeny . 7 55.9 11.24 8 55.2 11.02 18 64.10 12.25 1907 Original Progeny General average General Total per cent average number typical per cent trials kernels protein 33 33 58.1 60.2 11.56 11.72 1913 J Shaw : Studies on Influences Affecting Protein Content of Wheat 81 Eighteen of these thirty-three samples showed an increase of typical kernels in the progeny over the originals, the respective average being 60.2 and 54.6. The protein content increased in sixteen (16) out of thirty-three cases, with averages for originals and progeny of 11.56 per cent against 11.72 per cent. EXPERIMENTS OF 1908 The same experiments were continued in 1908 at Davis instead of Yuba City, and at Ceres instead of Modesto. The tabulated results of this season are presented below: 82 University of California Publications in Agricultural Sciences [Vol. 1 00 o 05 iH W < Q ^ o < CM r/; c -o CO ^■ ■-T^ 73 o oj ^ i=i to C-) in "^ lO on CO C^I ,-H CO r— 1 CM m. T-H r- o ,— i 1^ CO CO o CO CM CO CO CO o CO 00 \6 id CO co' CO CM CO s p. c3 c u 11 -+ fM T— 1 lO <~> irs CM CO C^l Oi ^ lO CO <-) C^l CO CO Tfl TtH ^ CM o\ CO t^ »o lO CM to L— L^ -* C^l o CO -i ^i J'i >-i i> K* K- r' o O m W ^ ^ w w w w w OO QO QO oo oo on 00 o o O w o o oo O' <—, \ \ \ \, \ o \ \ o t— I rH CO CO Oi Oi o o ■\ r-l I— I l^ l^ rr, 1- 1^ 1- 1- 1- o o r-i CM r-( i-H 00 oo 00 00 co Oi Oi Oi Oi Oi CM Oi Oi Oi Oi Oi Oi 1913] Shaiv : Studies on Influences Afecting Protein Content of Wheat 83 t^ rH GO O 00 »0 l^ lO O o ^' rA cm' OJ ^ h >0 Gvl kO - CO o t- ^ lO CM CO OC 1-H cc b- Tfl GO -g L- CO ira e- 00 oo t- t- L- L^ Oi lO L^ »o CM »o o "** Tfi CO -* TtH* rJH ^•S oo o CO 1—1 CM I— t CM ^ ,_ 00 00 GO Oi 00 l^ t- t- 00 c3 03^ C5 H p^ rH o o CO rA CO o Oi* 00 cc oq o* OC CO rH 1— ^ oo o t- a lO Oi" Cv I— 1 CO* t— t I—I 1-H I— 1 l—i 1 — 1 1— 1-H 1— CM r-^ r-H ^ C w "S S) C- -k^ p CM 0) lO Oi tH oo 00 Oi o CM CO 1-H Oi CM GO o. CO 1-H M L^ Oi 05 CO iO CO Oi rl- Oi CC lO ^ CD CO '"' 1— I— i CM rH 13 Pt CM 15 ^ fl CM c ^ o£ !>, "u) 0. be > ■» *3d ^ "So ^ "Sc ^ "bjD >^ "So 7. 'Sc >- < -1 cS ■— •r-l ^ S !h *^i p *£^ r- ^ 'B f-i ;h ;-i ^ ;3 <1 ►^ o '1 o H; o 1-^ O h-; O h^ o h^ O h^ O ^ C -^ .-S-s ■t:? Ti •73 •73 -TIJ n3 -TO o-^ = 3^ « 1. c3 CC 03 c: o 4i > c <73 c; 03 CC 1" 1 1 ^1 1= 03 a PI P cc 03 p o: "<* -. S S ^ ^ «M «4- pi P ?3 'S % ■^ n M ^ H &- w & O c S ■p^ M ^ M V. >^ > OC ) •< c > OC ) H GT a lS IT PC -^ ) OC 3 OC OC OC OO w " c > ^ ^ ^ ^ r 1-H ,— H 00 OC ) lO ir 3 C o o ^ lo ir 3 CO o- 3 TtH rl ^ t- t- - CO CC CO cc ^ Tt t^ i^ a s oo OC ) CO c»- J t^ t- - OO OC 3 Oi o- 00 OC 00 OC 00 00 84 University of California Publications in Agricultural Sciences [Vol. 1 Summarizing the results of the foregoing table for the three groups we find the following : Group I Group II Group III 1908 Number in group Per cent typical kernels Per cent total protein Number in group Per cent typical kernels Per cent total protein Number in group Per cent typical kernels Per cent total protein Original . 7 100.0 13.44 Non e of this type 10 72.23 13.59 Progeny . 7 98.7 15.14 seeded 10 97.80 14.54 1908 Total numbei trials General average per cent typical kernels General average per cent protein Original 17 83.6 13.54 Progeny 17 98.1 14.78 Discussion of 1908 Results. — Out of a total of seventeen cases twelve show both an increased number of typical kernels and an increased protein content in the progeny over the originals, the averages being as follows : Original Progeny Average per cent typical kernels 83.6 98.10 Average per cent total protein 13.54 14.78 In Group I, three, out of a total of seven, show a decrease in the percentage of typical kernels and the other four show the same as the original, the average being 98.7 per cent with an average protein content of 13.49 per cent in the original against 15.14 in the progeny. In Group III, consisting of ten samples, nine show an increase in both percentage of typical kernels and total protein, the average being: Original Progeny Average per cent typical samples 72.23 97.80 Average per cent total protein 13.59 14.54 The results expressed by groups are shown in the following table : Number of trials 21 Per cent of typical kernels A Per . P ;ent total rotein A Group I Original 100.0 Progeny 78.7 Original 13.00 Progeny 13.04 Group II 17 0.0 65.4 10.61 11.76 Grou}) III 34 61.97 80.1 12.44 13.03 1913] Shaw: Studies on Influences Affecting Protein Content of Wheat 85 GENEEAL DISCUSSION AND CONCLUSION Reviewing the results of the three years, the general average of typical kernels in the original was 63.63 per cent and of the ^eed produced therefrom 77.99 per cent, while the protein con- tent was 12.34 per cent and 12.95 per cent respectively. The results as a whole show: First — That in general the physical appearance of durum and red wheats is a fair indication of their relative protein content; kernels having a distinctly horny or glutenous appearance being higher in protein than those of a more or less dull or starchy appearance. Second — That there is a wide seasonal fluctuation in protein content of wheat which may become so great as to overbalance almost entirely any hereditary tendency of starchy originals to produce the same characteristics in their progeny. Third — That the protein content of wheat in a locality is undoubtedly largely dependent upon the seasonal precipitation in such locality. Fourth — That the use of perfectly typical glutenous seed is invariably followed under California conditions by a lowering of the gluten content, as indicated both by the physical appear- ance of the grain and by its protein content. Fifth — That if the original carries a considerable percentage of starchy kernels the progeny usually shows an increase toward the typical character to a degree determined by the character of the season in the locality. This is especially so with reference to the precipitation, which is in some instances may have such a strong influence as to cause a practically perfect grain to result from an original seed carrying 100 per cent of starchy kernels. Sixth — The last tabulation by groups further indicates quite strongly, however, that as a matter of fact the character of the seed used has quite a marked influence upon the progeny, and that the quality of the seed used, to some degree at least, deter- mines the character of the resultant crop, for it will be noted that as the originals decrease in both percentage of typical kernels and protein the progeny in each case decrease in the same order, although the effect of this is materiallv lessened and sometimes 86 University of California Publications in Agricultural Sciences [Vol. 1 almost entirely overcome by the character of the season, as shown by the other results. THE EELATION OF THE TIME OF PLANTING TO THE PROTEIN CONTENT OF WHEAT KERNELS On account of certain differences in the physical appearance of kernels from early and late planted wheats in preceding seasons, experiments were conducted in 1908 to ascertain more definitely the relation of early and late planting to the protein content of wheat kernels. In these experiments it was intended to conduct parallel series of plantings at the University Farm, Davis, and at the substation at Tulare. At the former place, however, conditions were not favorable for early seeding, and all had to be planted too late to be at all satisfactory in pre- senting any decided contrast in planting time, particularly for the winter wheats, there being but fifteen days between the early and late seeding. The first plantings of the season were not made until February 27, and the second plantings on March 13. At Tulare there was a wider difference, the plantings having been made on December 12, and January 17. As a matter of record, however, the analyses of these grains are presented below: Table 5. — Showing the Relation of Time of Planting to the Physical AND Chemical Characteristics of Wheat Kernels DAVIS, 1908 First ph mting Second p' lanting Lab. No. 2/05 Typical kernels Per cent 100.0 Total protein Per cent 11.81 Gliadin Per cent 1.41 Ash Per cent 1.76 Typical kernels Per cent 67.1 Total protein Per cent 10.67 Gliadin Per cent 2.40 Ash Per cent 2.04 847A 68.3 11.19 1.61 1.76 40.6 10.62 2.19 2.03 870A 100.0 13.78 1.80 1.73 100.0 13.74 3.12 1.72 873A 100.0 13.38 2.32 1.73 84.0 13.08 3.17 1.72 909A 96.9 14.41 3.60 2.07 97.7 14.89 4.99 1.49 910A 96.2 12.99 6.88 1.93 60.2 9.77 1.80 2.03 9111) 95.6 13.71 4.16 2.06 99.4 18.26 8.05 2.37 91 7D 100.0 17.25 6.95 2.16 100.0 19.68 5.41 2.08 91 9C 85.7 14.87 5.88 2.01 99.4 17.27 5.82 2.22 922A 99.0 14.58 4.15 2.00 99.1 12.07 3.09 2.10 595 95.3 14.91 5.90 1.89 93.3 13.24 5.53 2.13 Av. 94.2 13.88 4.06 1.92 85.5 13.94 4.14 1.99 1913] Shaw : Studies on In-jluences Affecting Protein Content of Wheat 87 TULARE, 1908 F'irst planting Second p^ lanting Lab. No. 901 Typical kernels Per cent Total protein Per cent 10.34 Gliadin Per cent 3.58 Ash Per cent Typical kernels Per cent Total protein Per cent 11.30 Gliadin Per cent 4.75 Ash Per cent 896 14.3 9.82 3.09 1.92 85.1 12.95 4.32 1.68 870 20.7 9.94 3.43 1.88 68.1 12.15 4.97 1.87 848 30.8 10.96 3.67 2.03 60.1 11.53 4.04 1.84 892 74.5 11.41 3.51 2.04 98.1 13.63 4.48 2.04 338A6 78.3 11.47 3.60 1.92 97.4 13.52 4.44 2.08 Av. 43.7 10.65 3.48 1.96 81.7 12.51 4.50 1.90 Grand av. 68.9 12.26 3.77 1.94 83.6 13.22 4.32 1.95 For the reason indicated above the plantings made at Davis should not be regarded as having much bearing upon the question. Considering the plantings made at Tulare, however, it will be noted that in every case the late plantings showed both a higher percentage of typical kernels and a higher protein and gliadin content than the early plantings. The average in the case of the Tulare samples was : Number of trials Per cent typical kernels Per cent total protein Per cent gliadin Early plantings .... 5 43.7 10.65 2.48 Late plantings .... 5 81.7 12.51 4.50 Further trials were made during the season of 1909-10 at Davis and Tulare. The planting dates at these stations were as follows : Early Late Davis February 27th March 13th Tulare December 26th January 25th 88 University of California Publications in Agricultural Sciences [Vol. 1 Table 6 Shoaving the Eelation of Time or Planting to the Physical AND Chemical Characteristics of Wheat Kernels DAVIS, 1909 First planting Second planting Lab. No. 870B Typical kernels Per cent 98.5 Total protein Per cent 15.77 Gliadin Per cent 5.77 Ash Per cent 1.75 Typical kernels Per cent 99.1 Total protein Per cent 15.46 Gliadin Per cent 6.16 Ash Per cent 1.90 873B 94.8 16.14 6.00 1.82 97.8 15.86 6.49 1.88 847C 99.0 15.46 6.05 1.73 98.0 16.01 6.52 2.13 909B 55.0 17.62 8.16 1.99 58.2 18.02 7.87 2.75 910B 97.9 16.66 6.20 1.79 100.0 16.82 5.94 1.98 922B 99.0 18.34 8.01 1.80 99.1 18.42 5.68 1.89 9]7E 98.0 18.42 8.35 2.21 100.0 20.02 7.44 2.45 388a5 100.0 18.18 7.71 2.17 100.0 18.58 6.92 2.28 875B 100.0 18.42 8.18 2.02 100.0 19.20 8.20 2.39 911E 16.82 8.11 1.79 19.44 9.14 2.12 912D 100.0 20.00 8.88 2.28 100.0 ]8.66 6.39 2.48 914D 98.0 17.62 7.86 2.03 100.0 17.62 7.91 2.45 Av. 94.5 17.45 7.44 1.94 95.6 17.84 7.05 2.22 Table 6 — (Continued) Lab. No. 1043aG ]040aG ]041aG ]042aG 1040aS ]041aS ]042aS 1 043aS ]151 1155 Av. Grand a Typical kernels Per cent 77.0 48.0 44.0 89.1 35.0 66.0 100.0 53.6 99.6 100.0 71.2 V. 82.8 TULARE, 1909 F'irst planting Total protein Per cent 10.73 11.13 11.07 13.12 11.36 10.50 12.89 10.62 15.38 17.20 12.40 14.92 Gliadin Ash Per cent Per cent 3.45 3.75 3.79 4.99 4.11 3.68 5.06 3.96 7.32 6.95 4.71 6.07 2.23 2.24 2.14 2.29 2.10 2.06 2.37 1.81 2.15 2.04 Typical kernels Per cent 100.0 100.0 99.0 100.0 100.0 100.0 99.2 100.0 99.8 97.7 Second planting Total protein Per cent 17.26 17.21 15.90 18.91 13.73 10.33 16.47 16.47 15.34 17.24 15.88 16.86 Gliadin Ash Per cent Per cent 6.31 5.50 5.35 6.65 5.91 6.19 6.50 5.38 5.97 6.51 2.86 2.20 2.40 2.59 2.22 2.34 2.54 2.74 2.25 2.46 2.34 These results show that out of twenty-two (22) cases, seven- teen (17) carried a higher protein content in the later plantings than in those planted early and that a like number out of the twenty-two carried either a larger percentage or an equal number of typical kernels in the late plantings. The averages are shown below: 1913] Shaw : Studies on Influences A f eating Protein Content of Wheat 89 Typical Total Trials kernels protein Gliadin Early plantings .... .... 22 82.8 14.92 6.07 Late plantings .... 22 97.7 16.86 6.51 To further secure data upon the effect of the time of planting upon the quality of the grain, twelve (12) varieties of wheat were seeded at Ceres on four different dates, in rows I6I/2 feet long and 12 inches apart, as follows : First planting November 28, 1908 Second planting December 12, 1908 Third planting December 31, 1908 Fourth planting January 19, 1909 The grain made a good stand and grew well during the season and matured as shown in the following table : Date of ElPENING Lab. No. Date of plantings Nov. 28 Dec. 12 Dec. 31 Jan. 19 914 June 15 June 18 June 22 July 17 909 June 14 June 18 June 20 July 7 910 June 18 June '20 June 20 June 24 911 June 16 June 20 June 26 July 7 915 June 20 June 24 July 3 July 7 913 June 16 June 20 June 24 July 7 917 June 15 June 16 June 19 July 7 916 June 11 June 18 June 22 July 7 919 June 16 June 20 June 24 July 7 912 June 16 June 18 June 22 July 7 1895 June 18 June 20 June 22 June 24 2/05 June 15 June 15 June 15 June 15 This series of plantings is of special interest in that out of the twelve varieties planted all but one show the highest protein content in the latest planting, and the one exception shows the highest in the third planting. In this case the difference between the protein content of the third and fourth plantings is less than one-half of 1 per cent. It is further of interest to note that there was quite a regular increase in the protein content in the order of planting. While the season was evidently one con- ducive to the development of a relatively high quality of grain 90 University of California Publications in Agricultural Sciences [Vol. 1 generally, it is noticeable that the average percentage of typical kernels also follows the same order as the protein content, al- though the difference is slight. If the average be made after discarding the last sample, which constitutes the single exception above referred to, the order in the average of typical kernels will appear absolutely the same as that of the protein content, and very consistently bears out the results secured at Davis and Tulare, previously discussed. While it may reduce the yield, relatively late seeding tends to produce a grain of better quality than does early planting. This same fact is further evidenced by a series of thirty- seven (37) types of New South Wales hybrid stocfe seeded at Davis in the season of 1910-11 ; the dates of planting being December 12, 1910, and February 20, 1911. The analyses from this lot are tabulated below : 1913] Shaiv : Studies on Influences Affecting Protein Content of Wheat 91 2 r. i; CM M " CO C^l o LO 00 IC CO GO C^l I— ^ CI Ttl o GC Cvl r— o Ol o o\ C-1 z <5i d eg CM ,-i' CM* cm' cm' CM* CM* cm' CM oi CM ca pin M •Sg w OO GO CO ,_! t- CO lO ^ ^ L':j d d d d d d d LO* d P^ rt =^^ w &< ^ X "E ^.5 ? t- Oi '^ c: CM CO o CO LO CO o C^l Ci 5 s: £ CM 00 t- 't t- o 't o CO q q &H t>^ CO L-^ t-^ oi 00 d 00* oo' t>^ 00 1^ o o T— ( 1— ( ^fln «} u ^^ o_ o O' O o o o o o o o LO o t~^ o ^ d d d d d d L- d S FCl t. o o Ci o o o o o o Ci Ci ^^- a^ oj ,_( T—l w c^^fLi t^ o < « "c < ^ « lO t^ (^ T— OO Oi '^ GO "* ,— ( CO o -f K aj " O o ^- o o: Ci q L- ^H q O <^^i ci c^i d CM ^ ^ CM ^ cm' CM oi cm' J Ph <3 c "c O c 18S LO t^ to LO CD t- CO Ci lO Oi 1^ Ci ^ LO CM ^. lO o 1—^ '^'t CC i-^ •^fe ^ t-^ id 1^ d CO d d Lo' d d LO d o^: o ■a- lO o L^ ^_^ Oi CO -* 00 LO Ci Ol T—l t^ CO CD 00 d eg t>^ 00 d CM d CO oo' lO d LO 00* t-' C-i -(Ih '""' ■ J < __^ -t- o g^g^. 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CO d Oo' 00 CO co" rH r-i Oo' rHrHCOCO-*-^lO»i^t^ Sad ^^ ^ ^ ^ ^ J2; ;3 r3 =! s =i ^ j^ ^ see cr! cj aj •^ "^ "^ "^ T^ "^ O) O O) O) ^ >^ i^ >^ i^ >^ Qi QJ M ,14 ^ >4 M Jtii P :3 S3 5h S-i Qj o c3 c3 rr ^ « =S C^ CS O -^ ^ o ;= S fi fl i=l CO ^ CO -^ '»/ XI' ?~1 V^M ^'m/ 'nT *-!■♦' ^-^-^ L^ '^'^ 'WJ ^^.^' ' 1 ^^ cococococooqoqoQoqoqoqoaoioqcococo CO CO CO t- t^ t^ L^ t^ 1^ t^ t^ t^ l^ t^ t^ t^ t^ 96 University of California Publications in Agricultural Sciences [Vol. (M C\r CM OCI (M (M cq c d> ci GOCirHt-OOilOrtl CM O CO »0 let) Tj^ O O rH* rH* d d d d d d -jSt-Oit^t^lOOCOlO ;:rHaiOiODOoooi C'r^C^lrHrHrHCMCMCMrH 0000 o o o o o d d d d d 00 oq iq- tq oq oq cm o:\ d d 1-^ i-^ lo* ^6 »o* i6 »0 'O CO CO rH rH L^ l- ci Ti ci 7i ci ci 3i 'c 'a "fl 'S 'c "s ^ ^ n— rH .^ >. >-, >> cu O; ci? o ^ ^ M rirf ^ !h Jj tJ fH ;h OOHHHHf^pHMM r^ r^ r-^ r^ 0) a a o o r/) m ^ ;h (Ti n a a ^ 03 oS ce ci o3 <33 be be ^ ^ ^ ^ MMooMMpqpq CO Oi CO Oi o p CD 1^ > X ,i ^. < m m CO -vD cr. rH o I -f •ct' I- 00 o rH 00 (X) CO CO CO -t CO r- cj o CM CO >o CO 00 cr^ rH CM ^ to -r -f -t ic o ».o icTi ir: »r:) CO CO CO CO CO CO CO CO CO CO CO I- i~ 1- 1- L- 1^ i^ OO cx) cx) oD cococococococococococococococococococococococococococococococo 1913] Shaw : Studies on Influences Afecting Protein Content of Wheat 97 Discussion of 1906 Results. — In these results the same thing is noticeable as in the former series, viz., that the samples grown- at Modesto as a whole maintained both a higher percentage of typical kernels and a higher protein content than those grow^n at Yuba City, the comparison by averages being as follows : Modesto Yuba City Average per cent typical kernels 89.70 65.2 Average per cent protein 11.87 10.5 It is particularly noticeable that, outside of the instances in which the originals carried 100 per cent of typical kernels, there was in this season a practically universal marked increase in the number of typical kernels in the progeny; that in the case of sample no. 714, which carried no typical kernels, the original seed being 100 per cent starchy, the second cutting produced 100 per cent of typical kernels and the first cutting (no. 713) 96.9 per cent of such kernels. Almost as good a showing also is made bj^ samples nos. 719 and 720, which produced respectively 96.1 and 96.3 typical kernels from entirely starchy kernels. It is further shown that in the case of the early cutting twenty-one out of the thirty-one trials show^ed an increase in the percentage of typical kernels in the progeny over the original, the relation in those cases in which increase occurred being 42.5 per cent in the original and 83.19 per cent in the progeny, while in the eight cases in which decrease occurred the averages were 96.1 per cent typical kernels in the originals against 75.3 per cent in the progeny, which, is entirely confirmatory of the results presented in Table 2. Looking more parti cularW at the specific question involved in this experiment, viz., the effect of the time of cutting upon the percentage of typical kernels and the protein content, it is found that the following averages hold: Modesto Number Per cent of typical Per cent trials kernels protein Early cutting 15 94.6 13.38 Late cutting 15 90.1 13.19 98 University of California Fublicaiions in Agricultural Sciences [Vol. 1 Yuba City Number Per cent of typical Per cent trials kernels protein Early cutting 16 66.1 11.98 Late cutting 16 64.6 12.05 These average figures show, in the case of the Yuba City lot, an apparent contradiction in that the early cutting with 66.1 per cent typical kernels showed 11.98 per cent protein, while the late cutting with but 64.6 typical kernels showed 12.05 per cent protein. When it is remembered, however, that the difference in the two cuttings is represented by but a single kernel in one hundred and that the average protein content is but seven- hundredths of 1 per cent, it will be seen that the discrepancy is only apparent, and well within the limits of error in either count or analysis. As a whole, it is shown that out of the total of 31 cases 11 showed an increase of typical kernels in the late cut grain and 14 showed an increased protein content, with the following rel- ative averages: Number Per cent of typical Per cent trials kernels protein Early cuttings 31 79.89 12.66 Late cuttings 31 76.9 12.60 The results for 1906 do not show that there is any marked difference to be attributed to allowing the grain to become thor- oughly ripe on the straw, as is generally done in California. EXPERIMENTS OF 1907 The experiments as to the effect of the time of cutting wheat upon its protein content were continued in the manner described above in the season of 1907 at Modesto, Yuba City, and Tulare, with the following results: 1913] Shaiv : Studies on Influences Afecting Protein Content of Wheat 99 CO o t- ix> Oi I— I Oi :o t^ Oi t^ i^ b- LO o QO Oi lo CD Ci r^ ^ 'M :o r-1(M0 03(MC5 0iOlrHOO1 oi (M* Cvi (M* Cvi i-I -A T-H (m' C4 CJ i-i ,-1* OJ Oi rn (M* CJ rH ;5 rH (M Oi CO 00 o c^" co' ^ 00 05 oo 1— I Ci i^ o t^ oj Ci oo ?OL^COCvl'*lt_Oai'-HCOCOQO i-H CO Ci CI r- o Ci Ci -+ Tt^ COOOCOOOCOOCOCOCO CvJCOCOCOCi as ' as" as* as as* as' as* as' d d as' go' as' as d oo' as* as* d o6 ^ 2 00* 00* 00* 00* as* i:asoicocDrHoioo] x^oooasoocoL^as-* ^1'2!='03rHOlOt-(M(MrHaSCOCMi— llOOlOCOCOt^ SFS'tl(M(Mr-l(MCOCM^'*t^^^COCOCOCOCO"-^ d S c H eg >^ai !>^a> t.^a; k^o t>.Q; >>^'^ i>~. '^ ^^ C ^' C ^' C'cC a.s^oooooooooooO'Cocoasas^ " -s '^ Tr d d d d d d d d d d , O O O q r-; rH o o CO CO d d r-' 1-H* i^ 00* 00* i^ ^* '^ OOOOOOOOe^lCMOOt^L-^OOTP^ '^ ri3 rfl r^ ri:i pC3 ,'-;,'-; ,-; OOQQQOMMM cC c3 c3 ci c3 03 ^ r^ ^ ^ ^ r^ fl 1=1 rt fl fl G Cj c3 cS cj c3 oS ^ ^ ^ ^ ,0 ^ O o o b^. I .c .:: a a o o '^ ^ ^ r^: '^OT^^iQi(^;ccot^i>-ooooasasoOi-HT-^C''5'^-|^' asasasasosasasasasasasa5asasasasasas-C]* cvi oi (m' \ L^ CM lO C^] »0 lO CO CO CO CM CM CM Ol CM CM CM C<1 C-00 rH O Ci Ci QC O O O CM* CM* rA rA rA CM* CM* CM ^ CM o 00 00 o Ci o o § 00 Ci OO o 00 rH rtH OO L-- CO OO CO Oi lO L- CO CM OO CO CO ; 00 t- CO o OI OI OO lO Ol rH |co CM CO CO CO CM CM '-H CO CO rH 1-i CO OI on r-i r—{ OI CO ; oi CO OI CO OI r-i ;::^ CO CO S£^3 CO o -* Ci O r-< Ol ri CM CM CM Cvl CMOOOCOOOOIO Ci O O rH l^ t^ L^ CM r-i Ol C^l CO CM CM CM CM L^^CiCiCOOCOHHCOCOrH TtH 00 L^ CO r-H 1-- O r-i lO Ol LO rH rH rH CM CM Ol Ol CO CO CO CO CO LO CO CO Ci CO rH 00 t^ O Oi rH rH CO lO rH CM CO rH GO oi oo' oi oo' d 00* »o* i-^ GO CO CO Ci ci CO CO ci oo" d -rtHTtl^TtiCOlOLOlOOOCOGOOOOOOiOOCOGOC/:Ci Oi >0 HH Ci Ci CO CO CO L-^ rH I- oo' CO L^ L- Oi oo t^ CM H^ CM 'H CM TfH Oi Ol Ci CM L^ CO L^ CO O] CO oo lO Ol CO Ol CO oo t^ Ol CO ■g Ol Cvl CM CM rH O) rH rH CM Cvl rH *|-s'-:t-^^-^^-5'-^t-^'-^^-^»-^-5CCl-^^>2 O O CD o o d- ■£ d> <£ <£ o o o o CD > o o be be O O CB CO Uj cn (1; Q; h^ fv^ t-i t> ^ r^ i: ^ PH ^ M M ft O n Ci c3 ci 4J n O 03 c ^ hr bf) o O K t* n n IH ^ ^ ,i3 O) o !3 '-» K* > o O pq pq O o ^- . I- CO o r-4 CO -r CO CO 1^ GO r-i o Ol CO CO I- 00 Ci o rH Ol CO HH to I- Ci e:,- -h -f »0 »0 >0 >0 »0 lO »0 lO CO CO O CO CO CO CO CO L^ I- l^ l^ l^ l^ L^ i^ ^iC C/j(XGO<>OGOCX)OOQOCOGOQOGCQOOOGOOOOOOOOOOOOOOCOOOOOOOO 1913] Shaw : Studies on Influences Afecting Protein Content of Wheat 101 =^-' CO o CI CO C 1 CO CI CO CI CI 'O ^ (M Cvj CM CM CI QvJ C^l CI CI " rt 00 to ^ CO CO o to QO o C5 o 7^ CO CO DO ^ ^ CO '^ co '^ 'tl 5 ^ Ci C^ CO rH L- O CO 1-; O T— ^ g o o ci ci o c^i CO i-H o CO cfi he CO O l-O lO I— CI H.^ rH r-i' r-i CM r-l CM CM CM X -H CO L^ ^ L- I- O C^l O O 03 O L- Ci (X Ci O r- CX) GO l- *'^ CM i-H i-i T-H r-i CM* CJ r-i i-i r-i C •,rt CO Ci CO t- C£5 C.1 O QC O ^ ^ CO i-H ^ L--; »0 1-1 T-H i-H O '^ •^ CO CO oi CO CO CO '* CO CO CO o ^ c '^•-^^OCil-OOOOT-Hl^O ^ ^ lO r-1 T-1 lO L— O O O' T-H O t-i g ci ci go" O OC d rH o ci t-^ & T-H r-i r-^ T-i ISfcit^OGOt-OOO'-HOi-HCO -g p CO «:> ^ CO LC L- O L- CO CI ^t r-i i-H rH t-H T-i T-i CI T-i T-i r-i Ci ^ T-H GO lO Cvl t^ CO Ci o CO CO CO CM CI -^ SS S ^ 00 Oi a £ ce t- t- -^ 3 S i=l ^ CM CM CM ^■ft^^Ci r- CO S >< a) 2 lO LO Ci XfH TjH O CO t^ nH ^^ GO GO o ^, CD CO Ci Ci Ci Ci CO CO L- L^ S be cS o C53 W pq > > O ci^ Ci Ci o t- CD d CM* CO CO I 3 F^ Ph CO'tlt-OCiOT-HClTtllO CiCiCiCiOOOOO CX)COGO00CiCiCiCiCi 102 University of California Fublications in Agricultural Sciences [Vol. 1 The averages for the three localities are shown in the following small table: Table Showing the Average Results From Early and Late Cut Wheats AT Three Station in 1907 Number of trials 12 Early cut Late cut A Modesto Per cent typical Per cent kernels protein 52.3 9.92 Per cent typical Per cent kernels protein 49.2 10.40 Yuba City 13 73.0 11.62 73.3 12.19 Tulare 5 56.4 11.00 57.8 10.92 Grand av. . 30 62.6 10.80 61.9 11.24 From a total of 30 cases, 12 showed either an equal or larger per cent of typical kernels in the late cutting than in the early cutting, a number altogether too large to indicate that the late- ness of cutting had any material influence in this direction, and this is further shown from the fact that the general average shows 62.6 per cent of typical kernels in the early cut lots and 61.9 per cent in the late cut lots. Again this is indicated in the protein content, for out of the 30 cases 15 show a larger percentage in the late cut grain than in the early cut lots, and the general average in protein content is essentially the same in the two lots, viz., 10.80 and 11.24 per cent respectively. For the two seasons the record stands as follows : Number of trials 27 Early cut Late cut Modesto Per cent typical Per cent kernels protein 77.68 11.8 Per cent typical Per cent kernels protein 73.7 11.95 Yuba City 29 69.1 11.96 68.5 11.20 Tulare 5 56.4 11.00 57.8 10.92 Average 61 71.1 11.80 69.9 11.51 These figures seem to show quite clearly that to allow the grain to stand on the straw until in the proper condition for handling with the combined harvester does not in any manner militate against its (juality either in physical appearance or pro- tein content, and slioukl set at rest any further discussion upon this point. 1913] Shaw : Studies on Injiuences Affecting Protein Content of Wheat 103 EFFECT OF SUNSHINE ON THE COMPOSITION OF THE WHEAT KERNEL It has long- been a matter of common knowledge that the composition of plants varies greatly under different conditions and in different localities. The exact environmental factor or factors which cause this variation in composition has been the cause of much discussion and investigation. It has already been remarked above that in 1882 Richardson observed that wheat grown in Colorado had by reputation a much higher gluten content than wheat grown from the same seed in Oregon. Not only was there a marked difference in the composition of the wheat grown in the two states, but he found that the wheat grow^n in Colorado had a higher gluten content than the original seed, while that grown in Oregon had a lower gluten content than the seed from which it was produced. From these observations Richardson and Blount concluded that the soil was the modifying factor. Wiley, however, draws the conclusion that the difference in gluten content is due to climatic conditions. Lawes and Gilbert in an elaborate series of experiments have shown that the use of manures and fertilizers have very little influence on the composition of the wheat kernel. On the other hand, they found a wide variation in composition in different seasons, Deherain in France also observed that a difference in seasonal conditions, especially during the ripening period, had a marked influence on the g'luten content of wheat. Similar observations have been noted by Thatcher of Wash- ington, and others. From these numerous observations and experiments it has come to be generally conceded that the gluten content is influ- enced mostly, if not wholly, by the climate. Wheat grown in the coast states is, as a class, much lower in gluten content than wheat grown in the central west, or the northwestern states. Even when seed of a high gluten content is introduced, a product, as Richardson observed, considerably inferior is the result. 104 University of California Puhlications in Agricultural Sciences [Vol. 1 Climate includes a large number of factors. The specific climatic factor which is the cause of this variation has recently been the subject of much study and investigation. The formation of organic compounds in the plant, such as starch and gluten, is a physiological process. The maximum development of these compounds is necessarily dependent upon favorable conditions. Starch is formed under the influence of sunlight. The formation of nitrogenous compounds requires not only an adequate supply of nitrogen, but also a supply of carbon compounds in the proper form and under the proper conditions. Just what these conditions are is not definitely known. In general, investigators have concluded that the large amount of sunshine prevalent in the coast states during the period in which the seed develops works directly in favor of the formation of large amounts of starch. In other words, that the gluten content is low only by reason of the formation of proportionally larger amounts of starch. Were this the case, the exclusion of portions of the sunlight should tend to increase the percentage of gluten. Theoretically the gluten would increase inversely with the amount of sunlight which the plants received. In order to determine w^hether or not sunlight is a prominent factor a series of experiments were planned in which portions of the natural sunlight were excluded from the growing plants. Duplicate experiments were conducted during the seasons of 1908 and 1909 at the Tulare Sub-station and at the University Farm at Davis. Original Seed. — At the Tulare Station in 1908 the originals used were as follows : No. 864/07 Weissenberg No. 879/07 Currell No. 892/07 Beloglina No. 894/07 Velvet Don (starch grains) No. 901/07 Turkey Red (gluten grains) No. 899/07 Yellow Gharnovka (gluten grains) At Davis the following varieties were used: No. 868/07 Kubanka No. 847 Kubanka No. 870A Velvet Don (gluten grains) 1913] Shaw : Studies on Iniiuences Affecting Protein Content of Wheat 105 The originals showed the following composition : At Tulare Lab. No. Name Per cent typical kernels Kernels in 10 grams Per cent protein Per cent gliadin Per cent ash 864 Weissenberg 95.9 325 15.25 3.63 2.66 879 Currell 87.6 351 13.55 5.06 2.11 892 Beloglina 59.4 271 10.96 3.84 2.33 894 Velvet Don 0.0 230 8.79 2.90 2.00 901 Turkey Eed 100.0 278 13.41 5.28 1.99 899 Gharnovka 100.0 280 12.20 4.26 2.02 At Davis Lab. No. Name Per cent typical kernels Kernels in 10 grams Per cent protein Per cent gliadin Per cent ash 868 Kiibanka 89.2 184 23.64 4.67 2 22 847 Kiibanka 48.6 11.03 3.88 1.97 870-G Velvet Don 90.1 239 17.38 4.80 2.05 Two rows of each of these varieties were drilled parallel into a bed 24 feet long. In the spring after the grain began to make an upright growth a series of lath screens was constructed and placed across the plat so as to shut off different proportions of the direct sunshine. The plat was thus divided into sections. At Tulare sectional screens were arranged so that they excluded three quarters, one half, and one quarter of the sunshine respect- ively. One quarter was left unshaded, and this received the full sunshine. In this manner one fourth of each variety received the same amount of sunshine. At Davis a similar arrangement was used, except that the amount of sunshine admitted was one third, one half, two thirds, and full. These screens were left in place until the grain was matured and harvested. Each portion of each variety thus treated was harvested separately and taken to the laboratory for analysis. The results are stated below: 106 University of California Publications in Agricultural Sciences [Vol. 1 Table 12. — Showing Effect of Various Amounts of Sunshine on the Gluten Content of Wheat 864 894 899 901 879 892 Av One-quarter sunshine Total gluten 17.55 12.10 12.66 15,33 18.17 15.39 15.19 Gliadin 8.000 4.930 5.333 6.602 8.000 6.674 6.589 TULARE, 1908 One-half sunshine Total gluten 18.00 12.72 12.61 15.45 18.63 16.58 15.665 Gliadin 8.065 5.350 5.311 6.986 8.406 7.157 6.879 Three-quarters sunshine Total gluten Gliadi Full sunshine Total gluten Gliadin 20.73 9.599 13.57 4.856 13.63 5.515 16.13 6.545 18.34 8.463 17.04 7.554 16.57 7.088 Gliadin ratio 43.40 43.91 42.77 DAVIS, 1908 847 870G Av, One-third sunshine Total gluten 13.19 12.69 14.30 13.39 Gliadin 4.17 4.46 4.71 4.445 Gliadin ratio 33.19 One-half sunshine Total gluten 13.94 12.37 Gliadin 4.17 4.09 13.15 4.13 31.40 Two-thirds sunshine Total gluten 14.10 13.40 13.53 13.67 Gliadin 4.42 3.50 4.21 4.034 Full sunshine Total gluten 13.79 12.47 13.17 13.14 Gliadin 4.28 4.00 4.52 4.266 29.57 32.46 EXPERIMENTS OF 1909 During the season of 1909 the same experiment was conducted at the Tulare and Davis Stations, with the exception that the following varieties of wheat were used: Gluten Gluten Starch Gluten Gluten Starch grains from Richi 1044A; grains from Kubanka 1045 A: grains from Kubanka 1045 A; grains from Turkey 1046A; grains from Beloglina 1047A grains from Beloglina 1047A, Determinations made upon these previous to seeding showed as follows : No. 1044A-G 1 045 A-G 1045A-S 1046A-G 1047 A-G 1047A-S Typical kernels Kernels in 10 grams Protein Gliadin Ash ]00.0 189 10.42 3.17 1.90 100.0 197 13.09 4.32 1.74 0.0 220 9.37 2.59 1.88 100.0 389 15.43 4.90 2.21 100.0 372 16.11 5.33 2.25 0.0 329 7.37 2.00 1.77 1913 ] Shaw : Studies on Influences Affecting Protein Content of Wheat 107 At Davis the originals and their analyses were as follows No. Name Typical kernels Kernels in 10 grams Protein Gliadin Ash 870G Velvet Don 100.0 227 15.92 4.27 2.02 870S Velvet Don 0.0 239 13.96 4.73 2.61 1045A-G Kubanka 100.0 197 13.09 4.32 1.74 1045A-S Kubanka 0.0 220 9.37 2.59 1.88 1041A-G Kubanka 100.0 177 13.05 4.12 2.02 1041A-S Kubanka 0.0 194 10.56 2.99 2.01 The gluten and gliadin content of the wheat samples from the experiments of 1909 are reported in Table 13. Table 13. — Showing Effect of Various Amounts of Sunshine on the Protein Content of Wheat Tulare, 1909 One-quarter sunshine One-half sunshine Three-quarters sunshine Full sunshine 1046G ' Total protein 10.62 Gliadin 3.516 Total protein 7.38 Gliadin 5.043 Total protein Gliadin Total protein 14.77 Gliadin 5.651 1047AS 10.96 3.998 12.32 4.413 15.56 5.577 13.18 4.084 1047AS 13.74 4.737 1045AS 11.64 4.100 12.04 4.271 13.86 3.783 13.35 3.839 1045AG 12.38 3.902 13.25 4.674 11.30 4.312 13.91 4.981 1044AG 10.90 3.271 11.41 3.436 14.99 4.385 11.59 3.720 Av. 11.30 3.757 11.27 4.368 13.92 4.514 13.42 4.502 Gliadin ratio 33.42 38. 74 32.42 33.54 Davis, 1909 One-third . sunshine A One-half sunshine A Two sur -thirds ishine A Full sunshine 1041AS Total protein 15.34 Gliadin 4.845 Total protein 16.24 Gliadin 4.850 Total protein 16.41 Gliadin 5.151 Total protein 16.02 Gliadin 4.970 1045AG 14.71 5.186 14.37 4.748 15.50 4.055 14.48 4.635 1045AS 14.71 5.680 * 15.56 6.248 14.25 5.850 870AG 16.53 5.341 * 15.62 4.867 15.66 5.214 870AS 15.79 6.816 14.06 3.770 15.50 6.418 15.50 6.645 1041AG 16.36 6.832 16.70 6.475 17.09 6.929 16.30 6.418 Av. 15.57 5.773 15.34 4.960 15.94 5.611 15.37 5.622 Gliadin ratio 36.82 32.33 35.20 36.57 * There was not enough material for a re-analysis of the sample. 108 University of California Puhlications in Agricultural Sciences [Vol. 1 Discussion. — If the proportion of protein to starch, or the per- centage of nitrogen, increased inversely as the amount of sun- shine the plants received we would expect the percentage of protein to be highest in the plants receiving only one quarter of the total sunshine and to decrease gradually to full sunshine. This, however, does not seem to be the case. Taking the average of the six samples grown at the Tulare station in 1908, we find just the opposite result. The protein content increases with the sunshine quite uniformly. The wheat from the plants receiving one-half sunshine contain .47 per cent more protein than the wheat from those receiving one-quarter sunshine. The wheat receiving full sunshine contained .91 per cent more than those receiving only one-half sunshine. Unfortunately the samples grown under three-quarters sunshine were lost, so that we are unable to say whether or not the protein content here would have been above or below that of full sunshine. The analj^sis of the individual samples in this set show that only one departs markedly from the average. In the variety no. 879 we find that the wheat grown under one- half sunshine had a higher protein content by .29 per cent than did that grown under full sunshine, while that grown under one-quarter sunshine is the lowest of the three by .17 per cent. In sample no. 899 we find that one-quarter and one-half sunshine gave nearly the same results, with a slight difference in favor of the former. The general trend of the results from 1909 experiments is much the same. The average of the samples grown under one- quarter and one-half sunshine are about equal, while the protein content of those grown under three quarters and full sunshine are much higher. If we exclude sample no. 10-46G grown under one-half sunshine, which is unusually low, the average for one-half sunshine is 12.25 per cent. This gives, then, quite a gradual increase in protein content from one quarter to three quarters sunshine, while the full sunshine samples average .5 per cent lower than those receiving only three-quarters sunshine. The results from the experiments at Davis are slightly more erratic, but the general trend is the same as that obtained at Tulare during the season of 1909. The samples under one third simsliine average .24 j)er cent more protein than did those under 1913] Shaiv : Studies on Influences Afecting Protein Content of Wheat 109 one-half sunshine. The samples under two-thirds sunshine aver- aged .52 per cent more protein than those under one-half sunshine, and .28 per cent more than those under one-third sunshine. There was, then, a drop in the full sunshine sample to about the same protein content as those receiving one-half sunshine. The results for 1909 at Davis came in the same order as those of 1908. The samples under one-third sunshine average higher in protein than those under t)ne-half sunshine by .23 per cent. The samples under tw^o-thircls sunshine averaged higher than those under one-half by .6 per cent, and than those under one- third sunshine by .37 per cent, w^hile the average of the samples grown under full sunshine is nearly the same as of those grown under one-half sunshine. These results certainly show that the protein content does not vary inversely with the amount of sunshine which the plants receive. On the other hand, the experiments at Davis and those of the year 1909 at Tulare tend to show that there is a happy medium under which the maximum amount of protein is stored. This optimum condition seems to be at a point somewhat below the normal sunshine. If, however, the amount of sunshine falls below that medium then again there is a decrease in the amount of protein stored. Just why this should be the case is still a matter of conjecture. It is quite probable, however, that it is due to a disturbed condition of the physiological functions within the plant brought about by the abnormally low sunshine. This fact can only be determined by a closer study of the formation and transformation of the various compounds in the plant. The gliadin content of the samples in this experiment seems to bear even less relation to the sunshine than did the total protein. In fact, there was no regularity whatever in the results those obtained at Tulare being just opposite from those obtained at Davis. A comparison of the two years at the two stations shows that there was a marked difference in the protein content of the samples in different seasons. At Davis we find that the samples averaged a higher percentage of gluten in 1909 than in 1908 by over 2 per cent. ] 1 University of California Pudlicatio7is in Agricultural Sciences [Vol. 1 Comparing the weather reports at Davis for the months of April, May, and June, we find that this period during 1909 was much drier and somewhat warmer than the corresponding months the year before. As this is the time when the greatest develop- ment of the kernel takes place, it is not at all unlikely that these climatic differences may account to some extent for the dif- ferences in composition of the grain. The moister and cooler coi^dition of 1908 may have prolonged the developing and rip- ening period, thus favoring the storing of a larger amount of starch. Other seasonal differences not recorded have doubtless also contributed their share. The difference in protein content for the two seasons at Tulare is just as marked as at Davis, but the order is reversed. No weather reports from the immediate vicinity were available, so we can make no comparison with the Davis conditions. Another rather striking seasonal difference brought out by the table is the percentage of gliadin to total protein. The years that the percentage of total protein is high, the percentage of gliadin to total gluten is also high. In fact, the difference in the gliadin content of the wheat samples for the two years is pro- portionally greater than the difference in total protein. This would lead us to believe that the gliadin is affected more by the season than the other protein compounds. We find, however, little or no relation between the gliadin content and the sunshine received. In conclusion, then, it is safe to say that while sunshine does exert some influence upon the composition of the wheat grain, there are other climatic factors which also exert very marked influences in this direction. We find that the protein does not increase inversely as the sunshine, but that there is an optimum condition under which the greatest development of protein takes place. This optimum of sunshine is somewhat less than normal in the valleys of this state. Other things being equal, too little sunshine lowers the protein content to just as great an extent as too much sunshine. This condition is probably due to the fact that a certain amount of sunshine is necessary in order that the normal x>h.ysiological functions of the plant may take place. When the amount of sunshine is reduced to one quarter or one 1913] Shaw : Studies on Influences A f eating Protein Content of Wheat 111 half of the normal it is quite likely that the plants do not receive enough sunshine to allow even the maximum nitrogen metabolism to take place. The fact that there is a greater difference in the percentage of protein for different seasons than there is in the same season under various amounts of sunshine certainly tends to show that there are factors other than sunshine, which play just as im- portant a part in determining the composition of the grain. Certain experimenters have stated that the exposure of grain to the action of strong sunlight after it had become ripe had a tendency not only to bleach the kernels, forming the so-called ' ' yellow berry, ' ' but also to lower the protein content. Attention was called to this by Lyon and Keyser based upon some trials made at the Nebraska station. On account of the fact that the sunshine in the main grain-growing regions of California is very intense during the ripening and harvesting period, and that the grain frequently stands for several weeks on the straw in the field, an attempt was made in 1906 at Yuba City to ascertain if this effect held under the conditions which obtain in this state. In this experiment several varieties of wheat were selected in which differences in the physical appearances of the grain could be easily followed owing to the color of the typical and changed kernels. The percentage of typical kernels in the orig- inal was determined, using 5000 kernels in each case as a basis, and these were seeded in plats under like conditions in the field. At the maturity of the grain three fourths of the grain was cut while in the hard dough stage, a few bundles being shocked and left in the field, while an equal number were protected from the direct action of the sunlight. The remainder of the grain was left on the standing straw from July 5 to August 13, when it was harvested and all three lots were threshed at the same time. The experiment was repeated again in 1907. A determi- nation was made of the percentage of typical kernels in each lot, and of the percent of protein. The results follow^ : 112 University of California Publications in Agricultural Sciences [Vol. 1 00 ^ tc Cvl CO < Cv! CvJ ^ ^ <-> on ^?i ^ tH n 1—1 cq I— 1 c a 6£ O Ci o H.d CM CM fi CCI C^] CM r-l I— I i—l CO O o o o CM o O 1— I o < CJ CM CM CM "^ CM Total protein 10.11 CM O T— I d O 00 CM oo CO 00 as oo o6 CO CO 05 00 ^ O CO rtH CM O T-H d d T-H T-H ^ g O . be ^ t^ bJO J3 h-j 13 S ^ 1-5 13 >• OJ .M o o O 1^ Tfi W) c ^ -^.S ^ o 03 03 ^ o 'oj 'a; ^ ,25 ,j5 w W pq o o o .13 X '"' lO CM CD lO CD C.° 00 Oi 00 Ci 1- I- ^'^. CD CD CD CD CD CD 1913] Shaw : Studies on Influences Affecting Protein Content of Wheat 113 o OS Q w Eh w o o ^ m hj w W Eh <1 W w o o t3 o S CO CO CM Oi CI to ; Ol »o Lo ; : I < Cvl CM Ol OJ OJ CM Cvl ca ■ Ol T-l CM ■ • ' --.2 ^ OO O lO lO BS ^. ^ t- CO CM ^ g oi TjH cm" 00* to O Ol O LO rH O l^ Ol CM CM t— I »0 Oi lO Gi GO Ol Oi T— I lO O CO oi CO r-i CO CO oi CO CO 'cSbfiCOOOCOCMGOCMOOOO -g p r-H lO CM Ol CO lO CO Ol Eh -2 oi oi oi CO* o-i co* oi cm* oi CM oi oi ■ss CM CO o CM O t— 1 Oi L- OO 00 O CO Oi ^ '-+1 00 Oi < oi CM OCl CM 1—1 CM I— ( '^ "-i 1— 1 ""^ ^ • • • tal tein 75 CSi GO CM lO OO »o CM CO lO CO OO o CO o i- ^|S CM I— 1 T— 1 I—I »o CO 1—1 1—1 rH 1—1 o Ol ^ g 11^ ^5 ^ Cvl Oi QO Ol CO O CO o O O CO OO 1—1 lO o CM 1—1 CM CM CO CM CM CM 1—1 CM CM fl OJ 3S CO o 00 T— ( CO CM Oi lO CM lO 1—1 I— 1 CM Oi CM 00 CM t— 1 CO CO CM T— 1 CO CM r— 1 CO CM 1— 1 CM 1—1 ^ O OJ OJ Oi CO Oi lO CO 00 CM rH CO CO Ol CO CO LO Oi l^ L-^ t^ t-- '^l I— I OOOiQOOiOiOiOOGOQOt^OiOi < < bp &)0 ^ ^ ^•' "' "■ ID ^ ^ 02 ^ ^ 1^ rzi ^ ^ ^ -^ ^ ^ %, ^ i-J 1-5 02 ^ 1-5 CO 'T3 it3 '^ 173 n "73 CO o ^ crt o niJ CO o 'nJ CPI CO o -713 1 Cin O) fl O. a Ph 4-> PI Ph O) fl ^ o ^ OJ ^ 0) ^ o 02 o rv o 2 OP o CO a; o Oh 03 u ^ 'Ti PI o n3 ^ o ^ 'TS o 'xi ^ PI o ^ 'TD o a a PI fl fl fl p) fl fl C C3 C3 a rt 03 OS KS Ki rt 03 a -^ br bfi b(l u > > > % 0) pl 03 03 o o o fl fl PI .^ -tI o a> o ^ J_l CO CO 7J O) O) o br br bn c^ ,^5 03 03 ,13 *S *S 'o ;3 J3 3 Of 13 ^ ^ bf) bfi o bx) M M M i^ f^ o O O pq W pq t cd 2 > > < <^ < 1—1 Oi o CO •t}h iO t^ 00 Oi T^^ lO CO CD lO CO CO CO CO 1^ t^ L^ 1^ t-- L^ 00 00 OO 00 OO 00 00 00 OO 00 00 00 114 University of California Publications in Agricultural Sciences [Vol. 1 The above results are not as consistent as could be desired in answering the main question involved in this experiment and no attempt will be made to interpret them as bearing upon this particular question. They do, however, further bear out the results discussed in the experiment on the effect of allowing the grain to stand on the straw in the field after reaching the hard dough stage, for it will be noted that in four out of six cases there was a larger percent of typical kernels in the late cut samples than in those early cut, and in one other case (no. 879) the percentage was essentially the same in the late cut sample as in that early cut. In the matter of total protein, the late cut grain all carried a higher percentage than did those of the early cutting. The average results from this standpoint are shown below : Per cent Per cent typical total kernels protein Early cut 69.1 12.92 Late cut 72.1 13.52 THE EFFECT OF IRRIGATION UPON THE PROTEIN CONTENT OF WHEAT The idea has been quite current among observant growers that whenever the rains extended late into the spring the quality of the grain of that season was materially reduced, that this had much to do with the wide seasonal differences in the quality of grain in California, and possibly was the main factor in causing such differences. This idea is quite in harmony with what has been observed in other experiments as to the effect of irrigation upon the quality of grain. No definite data being at hand as referring to conditions in California, in 1908-09 trials were made with six types of wheat at Davis to determine the effect of early and late application of water to growing wheat by planting these six types on uniform soil in rows at about the ordinary rate of seeding on three different plats. The plats received the following treatment so far as water was concerned: Plat A received irrigation. Piat B wa.s irrigated in the rows once just after the grain was out of the boot. 1913] Shaw: Studies on Influences Afecting Protein Content of Wheat 115 Plat C was irrigated in the same manner twice, once at the same period in the plants' growth as in Plat B and again just after the grain set. All plats, then, received the rainfall of the season and Plat B in addition had one irrigation and Plat C had two irrigations, the last one very late in its period of growth. The wheats used in the experiment and their original com- positions were as follows: Table Showing the Analysis of Original Wheats Used in Irrigation Trials at Davis, Cal. No. 730/06 Per cent typical kernels 96.0 Number kernels in 10 grams 276 Per cent total protein 12.83 Per cent gliadin 4.97 Per cent ash 2.32 726/06 87.7 245 13.55 4.42 2.20 870/07 227 15.92 4.27 2.02 049/08 73.9 313 12.50 4.24 1.99 870/07 90.1 239 12.17 4.12 2.27 338a2 100.0 284 11.28 2.13 The grains were seeded on December 7. They all came up with a good stand on December 28-31 and were harvested in two lots on June 24 and 30, there being but one or two days difference in the time of ripening between the irrigated and the non-irrigated plats. The analysis of the several lots grown on each plat is shown in the following table: 116 University of California Publications in Agricultural Sciences [Vol. 1 --SS 00 t- CO Cvl 00 Tt^ "-s 00 CO 00 t- CO rH 10 Ci 00 l^ t^ 00 00 t^ L^ L— q 00 53 '^od 1—1 r-i ^ rH fc« .o Oi (M 00 Ot) Oi Ci L^ 00 Ci Ci Oi Ci t^ 00 - Pw •^M i^ Ah *^.iH P CO 03 ■<*^ 1-H CO CO CO f^^^ '"^ "^ I-H rH rH "^ »-l M ^ISso t^ 00 CO 10 00 10 Num kerr in gra 27 Ci ^ »o r-i iO CO i-H CM CM CM Cvl CM er cent ypical cernels 86.0 q ci 10 q d CO CM* 10 Ci t^ Ci Ci 00 rjOOCOCOOCOOCM M q q ^ ^. "^ ^ <^ '^r-irHi— ir-icvir-ir-i «^ 00 10 10 10 c.S 00 t^ t^ CO GO ■^ £^ ^. CO 10 00 CO ■^ S2 i2 -* ^ CO CO 10 MH a:^^ ""^ ^^ •"^ ""^ ^ rr, Numbe kernel in 10 grams 283 rtH CO Ttl CO 10 »o 00 CO l- CO r-{ CM CM CM CM CvJ g g-^ o o o q q q 10 oi CM* oi Tti ■rJ^ Ci Ci Ci Ci Ci S.^ "^ Cvl CO : 00 CO S-c § CO CO CO xH Cvl 10 "« 00 00 00 : t- q 00 OO q t-. t- 00 00 S5*rH- r-i rA ■ r-i CM* r-i 53^ rH* I— i r-i T-H r-i eiH Ph cent adin .26 »o 10 CO ^__, i-Sco 00 TtH CO t- to CO 10 -* '"ti r-i .0 Per c( gliad 5.9 Cvl 10 CO q t- CO •3 r^" Tii Tji 10 id 10* ^' 10* CO ■^* id id 1 I--2 CM t^ 00 CM CO 'C 'c S «^ 00 00 CM 00 10 CO < s^ ^ CM iq 10 10 0^ g^ L- CO q 00 CM 00 1 12; 1 si^ 10* "^' 10 CO '^* t, (O CO* TfH* id -^ id tH rH y-i r-i ^2; 1 £&- r-i r-i rH r-i < .2 c u 2i^ r-i CO CO Ci 1 ^ ^ kernels in 10 grams 265 CO TtH CO r-i ce ^ .=« t: CM CM r-t ss CO Is 1 Ci CM 00 Cvl CO -^ £ £ Qj ■S^<^ CM CM CM CM CM £ r-i CM CM CM CM CM C pical rnels 17.0 q q C^I q (Z) oi I- »o* 10* 00* Ci CM oi oi CO o; ;,, a< oc Ci Ci Ci Ci Ci 00 Ci Ci Ci Oi Ci Ah ■".X 00 C3 Ci a ^ ^ (S-^ 00 Ci \ d > < -=' 6 "^ CO I- ^ 00 p^ r; CO i^ -^ t^ 00 ^^r^ Cl i~- CO ^k5 CO CM CO l^ 00 '-' 00 CO L- 00 r-i 00 CO 1913] Shaw : Studies on In-fluences Affecting Protein Content of Wheat 117 Examining these results, it will be seen that in both the early and late cut lots Plat A, which received no late application of water, carried the highest average per cent of protein, and that Plat C, which had two water applications, carried the lowest. Averaging the early and late cut lots, the following figures hold : Number A Per cent typical kernels 94.1 kernels in 10 grams 240 Per cent protein 14.70 Per cent gliadin 5.22 Per cent ash 1.85 B 88.1 235 13.78 4.81 1.94 C 83.1 238 13.40 4.51 1.84 This shows a gradual decrease in both the protein and gliadin content as the moisture was increased, is in entire harmony with results cited elsewhere, and seems to show that either irrigation or late rains tend to lower the gluten content of wheat, and that this climatic factor is a very prominent, if not the most important one in causing seasonal variation in the grain. Comparing the early cutting with the late cutting, it will be seen that while there is some fluctuation between corresponding samples in the two cuttings, the averages bear out the experi- ments cited in the earlier pages to the effect that no deterioration occurs from such late cutting, and as a matter of fact in this series of trials there was an actual increase in the protein content in the late compared with the early cutting; THE EFFECT OF EEDUCING THE ATMOSPHEKIC TEMPERATURE AT NIGHT UPON THE PROTEIN CONTENT OF WHEAT In the season 1907-08 an attempt was made to reduce the temperature, at different stages of plant growth, on certain plats on which were seeded several types of grain and to compare the protein content on these plats. The general plan of this experiment consisted of seeding several types of wheat in rows upon adjacent small plats of uniform soil. The rows were seeded north and south, and to prevent the plats from receiving the early sun and to assist in holding down the temperature in the early morning across the south end of the plats cooled during the first period of growth, a board fence was erected sufficiently high to shade during the 118 University of California Publications in Agricultural Sciences [Vol. 1 morning hours about one half of each plat throughout the period of cooling. From the time the grains were well up until the spring rains ceased a layer of ice was spread on a loose frame and placed over one half of each plat, within four inches of the top of the plants, every night during the first half of the growing period of the plants. A portion of the north half of each plat was left uniced. To retain more effectively the cooled air during the night the iced portion of the plats was entirely covered by a piece of heavy canvas. In this experiment two varieties of common wheats and five strains of durum wheats were used. The composition of each sample harvested is shown below: Table 14. — Showing Effect of Reducing Night Temperature Upon the Composition of Wheat Kernels Not Cooled Lab. No. 745B/08 Name Kubanka 1440 Per cent typical kernels 98.65 Number kernels in 10 grams 217 Per cent protein 15.04 Per cent gliadin 5.10 Per cent ash 1.84 851/08 Kubanka 2221 99.8 201 15.19 5.09 1.92 869/08 Kubanka 2239 99.6 177 15.77 5.44 1.87 871/08 Velvet Don 99.5 205 15.44 5.31 1.96 872/08 Gharnovka 99.5 207 15.15 5.09 1.83 920/08 Red Fife 96.9 361 17.40 5.82 2.19 962/08 White Fife 100.0 323 16.49 5.65 1.97 Avera ge 99.1 241 15.78 5.36 1.93 Cooled First Period Lab. No. 745B/08 Name Kubanka Per cent typical kernels 99.75 Number kernels in 10 grnms 254 Per cent protein 14.95 Per cent gliadin 4.52 Per cent ash 1.88 851/08 Kubanka 2221 99.70 233 15.31 4.96 1.23 869/08 Kubanka 2239 100.00 213 14.61 5.27 2.04 871/08 Velvet Don 99.94 229 15.87 5.32 1.86 872/08 Gharnovka 100.0 241 15.60 4.67 1.90 920/08 Red Fife 100.00 384 17.76 2.26 962/08 White Fife 100.00 380 18.24 5.75 2.41 Average 99.9 276 16.05 5.08 1.98 1913] Shaw : Studies on Influences Afecting Protein Content of Wheat 119 Cooled Second Period Lab. No. Name Per cent typical kernels Number kernels in 10 grams Per cent protein Per cent gliadin Per cent ash 745B/08 Kubanka 1440 100.0 217 15.24 5.39 1.96 851/08 Kubanka 2221 100.0 215 15.45 4.96 1.80 869/08 Kubanka 2239 99.8 203 15.80 5.43 1.90 871/08 Velvet D 99.9 246 15.53 4.25 1.90 872/08 Gharnovka 100.0 218 16.15 4.89 1.90 920/08 Eed Fife 97.5 350 17.80 5.96 2.31 962/08 White Fife 99.4 339 17.69 6.29 2.13 Avera ere 99.6 255 16.23 5.31 1.99 Collecting the averages for comparison, the figures are as follows : Number Per cent kernels typical in 10 Per cent Per cent Per cent Treatment kernels grams protein gliadin ash Not cooled 99.1 241 15.78 5.36 1.93 Cooled First Period 99.9 276 16.05 5.08 1.98 Cooled Second Period 99.6 255 16.23 5.31 1.99 While the figures for individual analyses are slightly erratic, yet it appears that the general effect of reducing the temperature in each period tended to increase the total protein, and that the tendency was greatest when the night temperature was reduced in the second period of growth, for in the case of cooling during the first period of growth five out of the seven trials showed a higher percentage of total protein than those grown under normal conditions, and the average total protein was 16.05 per cent against 15.78 in the case of the uncooled lot. In the case of the lot cooled during the second period of growth (after the grain was in the boot) all seven showed an increased protein content over the uncooled lot, the respective averages showing 17.23 against 15.79 per cent. Further, the effect of the cooling seems to have been greater from reducing the temperature during the second period of growth than during the first, for five of the cases in this com- parison show increased protein with an average protein content of 16.23 per cent against 16.05 per cent, and a gliadin content of 5.31 per cent against 5.08 per cent. 120 University of California Publications in Agricultural Sciences [Vol. 1 RELATION OF INCREASING THE SEVERAL AVAILABLE PLANT FOODS IN THE SOIL TO THE PROTEIN CONTENT OF WHEATS AT THE UNIVERSITY FARM, DAVIS, 1908-12, INCLUSIVE The general effect upon the protein content of wheat from increasing the available nitrogen and other plant food elements in the soil at the University Farm at Davis has been made the subject of study for the past four years and the results are discussed below. In these experiments Little Club wheat has been used each year. In order that any cumulative effect which might accrue from the nitrogen and the other plant foods used might be apparent, the seed from each plat was seeded back upon the same plat each succeeding season. The original seed used in these experiments was grown in 1906, and had the following composition: As In dry analyzed matter Moisture '. 11.28 Total protein 12.12 13.66 Gliadin 4.38 4.93 Glutenin 6.38 7.19 Non-gluten proteicls 1.36 1.58 Ash 1.62 1.82 Kernels in 10 grams — . 226 Bushel weight 59 lbs. For the four years 1908, 1909, 1910, and 1912 the average result was as stated in the table below. During the season of 1911 the land was under bare summer fallow on account of its foulness with wild oats, which accounts for the omission of that year. During these trials the one-twentieth acre plats received the indicated quantities of fertilizer each season. 1913] Shaiv : Studies on Influences Affecting Protein Content of Wheat 121 Table 15. Showing the Effect of Various Fertilizer Ingredients Upon THE Protein Content of Wheat Kernels Per cent total Per cent Fertilizer applied protein gliadin Ash 1. Nitrate of soda, 5 lbs.; hydrate of lime, 1321/2 lbs *10.36 3.000 1.75 2. Hydrate of soda, 5 lbs *11.08 3.280 1.73 3. Hydrate of lime, 1321/0 lbs. ...: 11.41 4.037 1.93 4. Cheek, no fertilizer 10.81 3.869 1.98 5. Nitrate of soda, 5 lbs.; sulphate of potash, 6 lbs ^ 10.99 3.816 1.95 6. Nitrate of soda, 10 lbs 11.00 4.130 1.99 7. Check, no fertilizer 11.18 3.866 1.86 8. Nitrate of soda, 5 lbs.; superphosphate, 20 lbs. 11.02 3.855 1.82 9. Nitrate of soda, 10 lbs.; sulphate of potash, 6 lbs 11.91 4.416 1.80 10. Nitrate of soda, 10 lbs.; superphosphate, 30 lbs 10.93 3.728 1.83 11. Check, no fertilizer 9.99 3.793 1.87 12. Superphosphate, 20 lbs 10.64 3.888 1.86 13. Sulphate of potash, 6 lbs 10.82 4.054 1.81 14. Check 10.77 3.978 1.79 15. Nitrate of soda, 5 lbs.; sulphate of potash, 12 lbs 10.94 3.806 1.82 16. Nitrate of soda, 5 lbs. ; superphosphate, 30 lbs. 10.57 3.878 2.20 17. Nitrate of soda, 10 lbs.; superphosphate, 30 lbs.; sulphate of potash, 12 lbs 10.76 3.870 1.90 18. Nitrate of soda, 5 lbs.; superphosphate, 30 lbs.; sulphate of potash, 6 lbs 11.00 4.291 1.87 19. Nitrate of soda, 5 lbs.; superphosphate, 30 lbs.; sulphate of potash, 12 lbs 11.35 4.703 1.90 20. Nitrate of soda, 5 lbs.; superphosphate, 50 lbs.; sulphate of potash, 6 lbs 11.92 4.815 1.91 21. Check 10.58 4.312 1.82 22. Sulphate of potash, 6 lbs.; superphosphate, 30 lbs 11.06 4.617 1.81 23. Dry blood, 7 lbs.; superphosphate, 30 lbs.; sulphate of potash, 6 lbs 11.24 4.748 1.86 24. Legume, 1907-08; nothing, 1908-09; super- phosphate, sulphate of potash, 1909-10 12.27 5.720 1.87 25. Superphosphate, 30 lbs., sulphate of potash, 6 lbs., 1907-08; legume, 1908-09; nothing, 1909-10 12.86 5.440 2.03 * Plats 1 and 2 were discontinued in 1910 on account of building and plats 28 and 29 substituted. 122 University of California Publications in Agricultural Sciences [Vol. 1 Table 15 — (Continued) Per cent total Per cent Fertilizer applied protein gliadin Ash 26. Sulphate of potash, 6 lbs., superphosphate, 30 lbs., 1908-09; nothing, 1907-08; legume, 1909-10 12.51 5.287 1.71 27. Check, no fertilizer 11.23 4.692 1.93 28. Nitrate of soda, 5 lbs.; hydrate of lime, 132yo lbs *11.91 5.265 1.86 29. Nitrate of soda, 5 lbs *11.89 5.065 2.14 * Plats 1 and 2 were discontinued in 1910 on account of building and plats 28 and 29 were substituted. THE EFFECT OF NITROGEN Collecting the results as to the effect of nitrogen upon the protein content, the following figures hold: Plats receiving nitrogen Check plats Plat Per cent No. protein 1 10.36 Plat No. 3 Per cent protein 11.41 2 11.08 4 10.81 Av. for 2 yrs. 10.67 11.11 Plat Per cent No. protein 9 11.91 Plat No. 5 Per cent protein 10.99 6 11.00 7 11.18 5 10.99 18 10.82 10 10.93 12 10.64 17 10.76 19 11.35 10 10.93 12 10.64 23 11.24 22 11.06 Average 11.10 10.95 From the above it does not appear that increasing the avail- able nitrogen content of the soil in these trials has had any material influence in increasing the nitrogen in the grain, nor has there been any cumulative effect shown by its use. This is shown by the individual cases as well as in the general averages. Considering individual cases, Plat 5 and Plat 6 may be compared, each receiving equal amounts of potash, while the former received also 100 pounds of nitrate of soda per acre, but it carried only .17 per cent more protein than the plat receiving no nitrate. Phit 6 received an application of 200 pounds of nitrate of soda, 1913] Shaw: Studies on Influe7ices Affecting Protein Content of Wheat 123 while Plat 7 received no fertilizer, and yet the average protein content of the latter shows .18 per cent higher than the former. Further, in the case where a complete fertilizer was used, as in Plats 17 and 19, the former receiving double the quantity of nitrate of soda, the latter showed .59 per cent protein above the former. The results for the entire period show that increas- ing the available nitrogen of the soil had no general influence toward increasing the protein content of the wheats, either when used alone or when used in connection with the other plant food elements. Comparing the effect of nitric nitrogen with organic nitrogen, as dried blood, in a complete fertilizer, the following results stand for the four years : 1908 Plat 18— Nitric nitrogen 9.24 Plat 23— Organic nitrogen 10.28 This set seems to show a very slight increase due to the organic nitrogen, but it is so slight as not to affect in any material way the quality of the grain, and the variations are such as to render it more than probable that such variations as do occur are due to other causes, possibly moisture, rather than to the nitrate present. THE EFFECT OF INCREASING THE NITROGEN CONTENT OF THE SOIL IN THE PRESENCE OF LIBERAL AMOUNTS OF PHOSPHORIC ACID In these trials, nitrogen in the form of nitrate of soda was used in connection with an application of phosphates, as shown in the tabulation: 1909 1910 1912 Average 11.32 9.99 13.45 11.00 10.77 10.85 14.08 11.49 itrogen and phosphate plats Check plats Plat Per cent No. protein 10 10.93 Plat No. 8 Per cent protein 11.02 10 10.93 12 10.64 8 11.02 12 10.64 18 11.00 22 11.06 20 11.92 22 11.06 Average 11.3 6 10.88 124 University of California Publications in Agricultural Sciences [Vol. 1 The average difference shows .28 per cent, an amount which is too small to be a matter of consideration for practical im- provement in the quality of the grain. Further, it will be noted that such differences as do occur did not run always in the same direction. THE EFFECT OF PHOSPHATES In these trials the superphosphate used was from treated rock and the amounts used are given in the scheme previously shown. Superphosphate plats Plat Per cent No. protein 12 10.64 8 11.02 10 10.93 16 10.57 20 11.92 19 11.35 22 11.06 Average 11.07 In general, the phosphates as here shown appear to have had a slight tendency toward increasing the total protein, but it is very slight on the average. In five cases out of seven, however, the phosphate plats carried somewhat higher protein than did the check plats. A more extended study, however, will be re- quired before any definite conclusion can be reached. THE EFFECT OF POTASH In these trials the potash was universally used in the form of sulfate in the amounts indicated in the general tabulation. Check plats Plat No. 11 Per cent protein 9.99 2 11.08 6 11.00 2 11.08 18 11.00 15 10.94 13 10.82 10.84 Potash plats Check plats Plat Per cent Plat Per cent No. protein No. protein 5 10.99 2 11.08 9 11.91 6 11.00 13 ]0.82 14 10.77 15 10.94 5 10.94 19 11.35 18 11.00 Aver age ] ] .20 10.96 1913] Shaic : Studies on Influences Afecting Protein Content of Wheat 125 There is shown a slightly increased protein content on the potash plats over the corresponding checks. Three out of the five cases show a higher protein content on the potash plats than on the checks, and one shows the same percentage on both plats. 'The difference is so small in the average that it might easily be due to difference in the moisture content of the soil, but data along this line as relating to these plats are not at hand, and therefore it would be unwise to attempt to draw conclusions until such data are secured. THE EFFECT OF GREEN MANURE CROPS Plats 23, 24, and 25 have had legumes grown upon them every third year and cereal crops the other year of the rotative period, with superphosphates and potash added the second year after the legume. Comparing the result from these plats for the short period the trials have been under way with the average of the check plats, and with the average of those on either side, the following results appear: Per cent protein Plats with legumes 11.06 Average of all checks, no legume 11.02 Average of two nearest checks, no legume .— 10.90 It is not apparent that any material change in protein content has been effected by the treatment employed. GENERAL CONCLUSIONS The results presented in the foregoing pages seem to warrant the following conclusions : First — There are important seasonal, varietal, and individual variations in wheat plants with respect to protein content. Second — The principal factor causing the most pronounced variation- in the protein content of wheats is climate, particu- larly the moisture supply in the later growing period of the crop. Third — The tendency of wheat kernels to change from a glutenous to a starchy condition is not a constant one, but is mainly dependent upon the individuality of the plant and upon seasonal influences, particularly moisture supply in the latter part of the growing period of the plants. 126 University of California Publications in Agricultural Sciences [Vol. 1 Fourth — In wheats 100 per cent of which are entirely starchy there may be a reversion to an entirely glutenous condition in a single season, or the reverse may occur, dependent upon the seasonal condition. Fifth — Allowing the grain to stand on the straw in the field until fully ripe does not materially affect the protein content. Sixth — The protein content of wheat is affected by the time of seeding, the product of late seeded grain having a higher percent of protein than that of early seeded grain. Seventh — The protein content of wheat is very largely influ- enced by the water content of the soil in the later period Ox its growth, and the effect of either irrigation or rainfall during this period is to lower its protein content. Eighth — The percentage of sunshine which the grain receives during its period of growth has a somewhat direct bearing upon its protein content, but other seasonal conditions are more im- portant. Ninth — Retarding the growth through cooling the atmosphere has a tendency to increase the protein content. Tenth — The quantity of available nitrogen in the soil either alone or in the presence of other available plant foods, provided there be sufficient to supply normal growth, appear to have little, if any, influence upon the protein content. Eleventh — The low gluten content of wheats grown in Cali- fornia is not due to soil exhaustion, but rather to the following causes: (1) To climatic factors which allow a long growing period; (2) to relatively early seeding; (3) to the use of varieties inherently low in gluten; (4) to a lack of selecting highly glu- tenous seed. Acknowledgements : The author is greatly indebted for valu- able assistance rendered in the prosecution of various parts of the routine analytical work which furnishes the basis for this paper to Miss Rachel Corr and Messrs. J. D. Rose, B. A. Madson, and E. H. Walters, and also to Messrs. A. J. Gaumnitz, H. Fi Blanchard and J. T. Bearss for the careful attention to the field production of the samples. Transmitted January 2d, 1913.