.. . 3 GEAD3S FOR RIFE OLIVES/*' By Frederic T. Bioletti T niv. of Calif. Agric. 7xpt . Station Bulletin Ho. 263 UNIVERSITY C AT LOS UNIVERSITY OF CALIFORNIA PUBLICATION COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA SIZE GRADES FOR RIPE OLIVES BY FREDERIC T. BIOLETTI BULLETIN No. 263 Berkeley, Cal., January, 1916 CITRICULTUR UNIVERSITY OF CALIFORNIA PRESS BERKELEY 1916 BENJAMIN IDE WHEELER, President of the University. EXPERIMENT STATION STAFF HEADS OF DIVISIONS THOMAS FORSYTH HUNT, Director. EUGENE W. Hn CARD, Agricultural Chemistry (Emeritus). EDWARD .1. WICKSON, Horticulture (Emeritus). HERBERT J. WEBBER, Director Citrus Experiment Station; Plant Breeding. HUBERT E. VAN NORMAN, Vice-Director; Dairy Management. WILLIAM A. SETCHELL, Botany. MEYER E. JAFFA, Nutrition. ROBERT H. LOUGHRIDGE, Soil Chemistry and Physics (Emeritus). CHARLES W. WOODWORTH, Entomology. RALPH E. SMITH, Plant Pathology. J. ELIOT COIT, Citriculture. JOHN W. GILMORE, Agronomy. CHARLES F. SHAW, Soil Technology. JOHN W. GREGG, Landscape Gardening and Floriculture. FREDERIC T. BIOLETTI, Viticulture and Enology WARREN T. CLARKE, Agricultural Extension. JOHN S. BURD, Agricultural Chemistry. CHARLES B. LIPMAN, Soil Chemistry and Bacteriology. CLARENCE M. HARING, Veterinary Science and Bacteriology. ERNEST B. BABCOCK, Genetics. GORDON II. TRUE, Animal Husbandry. JAMES T. BARRETT, Plant Pathology. FRITZ W. WOLL, Animal Nutrition. A. V. STUBENRAUCH, Pomology. WALTER MULFORD, Forestry. W. P. KELLEY, Agricultural Chemistry. H. J. QUAYLE, Entomology. I). T. MASON, Forestry. J. B. DAVIDSON, Agricultural Engineering. ELWOOD MEAD, Rural Institutions. H. S. REED, Plant Physiology. WILLIAM G. HUMMEL, Agricultural Education. LEON M. DAVIS, Dairy Industry. JOHN E. DOUGHERTY, Poultry Husbandry. S. S. ROGERS, Olericulture. FRANK ADAMS, Irrigation Practice. DAVID N. MORGAN, Assistant to the Director. Mrs. D. L. BUNNELL, Librarian. DIVISION OP VITICULTURE AND ENOLOGY F. T. BIOLETTI W. V. CRUESS W. F. OGLESBY F. C. H. FLOSSFEDER L. BONNET A. E. WAY SIZE-GRADES FOR RIPE OLIVES By FREDERIC T. BIOLETTI Uses and Methods of "Sizing." Pickled olives are sorted into several grades based on size. This is necessary for various reasons. When the sizes are mixed, the olives are less attractive in appearance. The large sizes have a greater commercial value. The price paid by the pickler to the grower depends on the size of the fruit. Finally, it is impossible to process olives of various sizes together with the best results. Various devices are used to separate the various size-grades, but they all depend on the variations in the shortest diameter of the olive. The unit of measurement used is called a "sixteenth," which means a sixteenth of an inch. Olives with a diameter of less than 9 sixteenths are usually rejected for pickling. All above this size are separated into grades differing from each other by one or more sixteenths of an inch. No accepted standard of grades has been established for olives as for prunes and raisins. An examination of the various brands of canned and bottled olives on the market shows great diversity both in the segregation of the various grades and in the methods of designating them. Uniformity in this matter is very desirable. The buyer wants to know exactly what he is getting; the seller needs to know exactly what the buyer is ordering. Variations in Practice. In order to determine the variations in practice and whether there was any tendency towards uniform stand- ards, an examination was made of a number of samples of olives collected in the open market. Of these samples eighteen were in bottles and thirty-three in cans. They include the best brands of eleven picklers and handlers of northern, central, and southern California, and therefore represent the present practice fairly. The examination included the volume of the container, the weight of the olives and of the brine, and the number of olives. Certain samples of typical sizes were carefully measured to determine varia- tions in size. Some of the data obtained is given in the following table : [215] 232992 216 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION TABLE I SIZE-GRADES OF COMMERCIAL EIPE OLIVES Samp No. 5 'le Designation on can or bottle Jumbo. Sevillano Weight of Olives Ibs. .85 Size of container 6 640 cc Number of Olives 30 Number of Olives per Ib. 35 5 Mean diam. 16ths in. 16 05 23 Jumbo. Net contents 1 qt. 1.22 53 43 6 99 Jumbo Net weight 2 Ibs. 1.12 54 48 3 19 Fancy 1.47 6 950 73 49 7 ?0 Fancy . .26 6 225 14 53.4 1 Fancy. Mission . .95 6 640 56 58.9 13,63 1? X Mission 1.02 6 665 63 61.4 13 60 6 No. 1 Mission .88 6 640 54 61 5 13 70 9 13 Extra Fancy Mission and Manzanillo-. XX Mission .99 .96 6700 5 665 64 65 64.6 67 6 13.30 13 24 43 Lar^e size Contents 20 oz. 1 66 1035 112 68 10 Fancy Mission 1.00 6 700 72 73.4 12 69 24 Fancy. 1 qt. net.; 1 Ib. 4 oz. net wgt... 1.37 970 100 73.0 47 Fancy Net w't 16 oz 53 485 39 73 15 Mammoth size. Mission .62 460 46 73 8 25 Fancy. 1 pt. net; 10 oz. net wgt .67 490 49 740 37 Fancy. Net wgt. 16 oz .53 485 39 750 14 XXX Mission 1.07 6 665 81 75 7 12 57 38 Fancy. 1 qt. net; 1 Ib. 4 oz. net wgt... 1.30 970 100 76.0 18 Mission .65 6475 50 77.4 39 Fancy. 1 pt. net; 10 oz. net wgt .61 490 49 80.0 2 Extra large. Mission 1.08 6 640 91 84.0 11 89 36 Fancy. Net wgt. 2 Ibs 1.05 965 91 86.0 31 Net contents 1 pt. ; wgt. olives min. 9 oz. .57 485 50 87.0 7 No. 2 Mission .. .. .91 6 640 80 87.9 11.98 50 9 oz. net .68 530 60 88 44 Net wgt. olives min. 1 Ib. 3 oz. 1.21 970 108 89 46 Fancy. Net wgt. 2 Ibs. 1.13 965 90 89 16 Extra large size. Mission .58 460 52 89.6 48 Extra large size. 29 oz. net wgt 1.14 855 103 91 30 Net wgt. olives min. 1 Ib. 3 oz 1.19 970 111 92 3? Extra large size. 29 oz. net wgt 1.14 855 106 92.0 45 Net contents i pt. ; wgt. olives min. 9 oz. .57 485 53 93.0 29 Large size. Contents 20 oz 1.25 1035 118 94.0 11 Large Mission 1.10 6 700 106 95 9 11 55 ?8 Net wgt. 3032 oz. 1.11 855 100 98 ?1 Fancy .14 6 150 14 98 6 27 Net contents 15 oz .55 475 55 99 51 Fancy .. 1.07 840 108 101 35 9 oz. net .60 530 61 102 26 34 Contents, incl. brine, 1 Ib. 13 oz 18 oz. fruit net 1.08 1.21 860 111 125 103.0 103 11.57 3 Large. Mission ... 1.06 6640 109 103.0 NOTE. Samples marked 6 were in bottles, the others in cans. SIZE-GRADES FOB RIPE OLIVER 21' TABLE I (Continued) SIZE-GRADES or COMMERCIAL RIPE OLIVES Samj No. 42 40 41 17 49 4 33 8 le Designation on can or bottle Net wgt. 30-32 oz Weight of Olives Ibs. 1.03 Size I Of container 855 860 475 460 995 b 640 fo640 Number of Olives 107 117 65 66 125 133 80 139 Number of Olives per Ib. 104.0 105.0 105.0 110.0 115.0 127.1 136.0 156.4 Mean diam. 1 ;ths in. Contents, incl. brine, 1 Ib. 13 oz 1.11 Net contents 15 oz .61 Large size. Mission .60 18 oz. fruit net 1 31 Medium. Mission 1 04 9.95 15 oz. net wgt 58 No. 3 Mission . .89 9.98 NOTE. Samples marked b were in bottles, the others in cans. This table shows great variation in usage. Samples labeled Jumbo or Mammoth vary from 36 to 74 per pound; Fancy from 50 to 108; Extra Large from 84 to 106, and Large from 68 to 110. It is thus possible to buy olives labeled "Large" which require only 68 to make a pound, while "Mammoth" olives might require 74 and "Extra Large" 106. It is desirable that the cans should be designated by words, numbers or signs that would give the buyer information on the size and weight of the olives he is buying, and also perhaps of the number in a can. Tendency of Current Practice. There seems to be a general ten- dency to distinguish by descriptive words five sizes. These are (1) Jumbo, Mammoth or Extra Fancy; (2) Extra Large or Fancy; (3) Large; (4) Medium; (5) Small. Some label their various sizes 1, 2, 3, etc.; others X, XX, XXX. Table II shows that the first four sizes include olives whose average diameter range from 16 sixteenths to 10 sixteenths of an inch. Those smaller than this are not often pickled for the general market. While this general tendency exists, the indi- vidual variations are very great and the words, numbers and signs of the various brands have no common standard or meaning. Basis for a Common Standard. In order to establish the basis for a common standard, an attempt was made to discover the relation between diameter and number per pound. The data in Table II indi- cate that this is not a fixed ratio. It varies in fact according to the shape of the olive and its specific gravity. With the same diameter it will require more olives of a rounded variety, like the Manzanillo. to weigh a pound than of an elongated variety, like the Sevi llano. 218 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Fresh olives will weigh less than pickled olives of the same size and shape, owing to the salt contained in the latter. Sample No. TABLE II EELATION OF DIAMETER TO WEIGHT AND DESIGNATION Diameter in 16ths of an inch O 6 1 12 9 13 10 14 Designation Jumbo 17.12 No. 1 Fancy 14. X 14.08 Extra Fancy 13.76 XX 14.40 Fancy 14.08 XXX 13.44 No. 2 12.80 Extra Large 12.48 Large 12.00 Large 12.32 No. 3 10.72 Medium .. 10.40 Max. Min. Mean D jUIOUgUI Mean L 1.1 11 III IH- 1 per Ib. L/D 17.12 15.04 16.05 21.41 35.5 1.334 15.04 12.80 13.70 18.32 61.5 1.338 14.88 12.64 13.63 18.05 58.9 1.357 14.08 13.12 13.60 16.48 61.4 1,212 13.76 12.48 13.30 17.17 64.6 1.291 14.40 12.48 13.25 16.59 67.6 1.252 14.08 11.68 12.69 17.62 73.4 1.388 13.44 12.00 12.57 15.74 75.7 1.250 12.80 11.36 11.98 15.90 87.9 1.327 12.48 11.36 11.89 16.56 84.0 1.393 12.00 10.24 11.57 15.87 103.0 1.372 12.32 10.24 11.55 15.55 95.9 1.346 10.72 8.64 9.98 14.00 156.4 1.402 10.40 9.28 9.95 14.57 127.1 1.466 For olives of the same shape and specific gravity the number per pound will vary inversely as the cube of the diameter. For example, an olive whose diameter is 16 sixteenths will weigh 8 times as much as a similar olive whose diameter is only 8 sixteenths. It will there- fore require 8 times as many of the latter as of the former to weigh a pound. While the olives of a given variety vary somewhat in shape, accord- ing to stage of development and other factors, these variations lie normally within certain limits and the average shape of well-developed olives of any variety is fairly constant. This makes it possible to find a factor which will enable us to calculate the number of olives per pound for any diameter of a given variety with a fair degree of accuracy. This factor will be different for each variety of different shape and will depend particularly on the elongation of the olive or the ratio between length and thickness. From a large number of weighings and measurements, a factor has been determined for each of several of our principal pickling olives and from this factor the number of olives to the pound for the various sizes. Thp results are shown in Table III. SIZE-GRADES FOR RIPE OLIVES 219 TABLE 111 RELATION OF DIAMETER TO NUMBER PER POUND KOR VARIOUS VARIETIES OF OLIVES (PICKLED) Number per pound = K -4- D Fairoaks Average Mission 257 282 *244 181 198 190 132 144 142 99 109 107 7.') 83 82 (50 (if! (if) 47 52 52 39 43 42 32 3.-> 3f) 30 29 Diameter 8 Manzanillo No. 1 313 Ascolano 290 Agostino 286 Cucco 264 9 220 204 199 186 10 160 148 146 135 11 121 112 110 102 12 93 86 85 78 13 75 68 67 (51 14 58 54 53 49 lf> 48 44 43 40 16 39 3(5 3(5 33 17 33 30 30 28 L/D 1.168 1.238 1.288 1.303 1.392 1.328 K = Number of olives per pound of size 10 multiplied by 1000. L = Average length of olive. D = Average thickness of olive or diameter. L/D = Average ratio of length to thickness. * The numbers corresponding to diameters 8 and 9 for the Mission were determined by actual weighings of these sizes. The numbers are slightly lower than would be found by calculation, owing to the fact that the undeveloped olives are more elongated than those over 10. From this table it is possible to find the number or olives required for a pound of the various sizes of the different varieties. The dependence of the number on the ratio of length to thickness, L/D, is clearly shown. Of the Fairoaks variety, which is 1.392 times as long as wide, 257 olives of the 8 sixteenths size weigh one pound, while of the Manzanillo No. 1, which is only 1.168 times as long as wide, 313 of the same size are necessary. The numbers for the smaller sizes 8 to 10, inclusive, are probably a little high. The measurements used to determine the factor K were made on olives ranging from 10 to 16 sixteenths. Olives smaller than this are usually undeveloped and are more elongated than the type. They will, therefore, be heavier in proportion to their diameters and it will require less proportionately to weigh a pound. The number of size grades which it is desirable to separate depends on the objects to be accomplished. The number which it is possible to separate depends on the perfection of the grading machine or device used. 220 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION CQ SIZE-GRADES FOR RIPE OLIVES 221 In figure 1 is shown in diagrammatic form the sizes and variations found in the various grades of four of the largest picklers of ripe olives in California. A glance at this diagram shows that picklers A and B separate their olives into four fairly distinctive size-grades. Picklers C and D appear not to have had any very large olives and, in grading, probably simply eliminated the fruit that was too small. Table IV shows the differences between the average sizes of the various grades for each pickler and the range from the largest olive to the smallest. TABLE IV DIFFERENCES BETWEEN GRADES (in sixteenths of an inch) Grades 1-2 2-3 3-4 Average Total range Pickler A 1.74 .32 1.62 1.23 5.60 Pickler B 2.38 1.72 2.00 2.03 8.48 Pickler C 61 1.34 .98 3.52 Pickler D 35 .66 .51 2.08 Table V shows the extreme variation in size of olives in each grade for the same picklers. TABLE V VARIATIONS IN EACH GRADE (in sixteenths of an inch) Grades a Pickler A 2.24 Pickler B 2.06 Pickler C 1.26 Pickler D The most methodical grading is evidently that of B. Although including a larger range of sizes of olives, the differences between grades and the variations within the grades are more uniform than those of any of the others. As all sizes of olives between the extremes of the largest and the smallest are likely to occur, the range of variation within each grade should be equal to the difference between the average sizes of two adjacent grades, where the grading is done accurately. This condition is most closely approximated by B, where the range of variation and difference between grades is very close to 2 sixteenths. It would seem, then, that a difference of 2 sixteenths between grades would be suitable. There is no advantage in having the average 1 2.24 2 1.12 3 1.96 4 1.12 Average 1.56 Total range 5.60 2.06 2.24 1.44 2.08 1.96 8.48 1.26 2.40 2.08 1.91 3.52 .96 1.90 1.44 1.44 2.08 222 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION size of two adjacent grades closer than the variation within a grade, as in C and D. This variation exceeded 2 sixteenths with all the picklers except D, and in this case it was very near to this figure. The grading illustrated in figure 1 under "Standard" is based on this difference of 2 sixteenths. As the olives are graded before processing, the sizes of the fresh olives indicated in the diagram would not necessarily be exactly the same as those of the pickles, but the difference would be slight. Tests made show that there may be increase in size of a little over 2 per cent. TABLE VI INCREASE OF SIZE IN PICKLIN<; Fresh Olives Pickled Olives Increase Variety Sample 1 Sample 2 Sample 3 Sample 4 13 sixteenths 13 sixteenths 13 sixteenths 11 sixteenths 13.36 13.31 13.24 11.15 = 3% = 2.4% = 1.9% = 1.4% Manzanillo No. Agostino Cucco Fairoaks 1 Average increase = 2.175 Table VII gives the principal data regarding the standard for size- grades which corresponds nearest to the present practice. It divides the olives usually pickled into three size-grades, 1, 2, and 3, called respectively Extra Large, Large, and Medium. These are all over 11 sixteenths before pickling. The smaller olives, if pickled, could be divided into two other grades, 4 and 5, called Small and Extra Small. Size 1 would include all olives which- failed to pass through a 15 six- teenth screen, size 2 those retained by a 13 sixteenths, and so on. The fourth column gives the approximate average size of the pickled olives and the fifth column the number of pickled olives to the pound, varying according to variety. TABLE VII STANDARD FOR SIZE-GRADES (Based on present practice; difference 2 sixteenths inch) Extra large Size 1 Range 17-15 Average 16 Number per Ib. 32 to 39 Large 2 15-13 14 47 to 58 Medium 3 13-11 12 75 to 93 Small . 4 11- 9 10 132 to 160 Extra small ... 5 below 9 SIZE-GRADES FOR RIPE OLIVES 223 Table VIII shows the average number per pound for each size for our commonest pickling varieties. The actual sizes of the four grades are shown in figure 1 under "Standard." TABLE VIII NUMBER PER POUND OF COMMON VARIETIES WITH THE PRESENT GRADING Average number per Ib. Retaining Average Designation screen* diameter* Mission Sevillano Ascolano Manzanillo No. 1 Kxtra large 15 16 35 33 36 39 Large .. 13 14 52 49 54 58 Medium 11 12 82 78 86 93 Small .. 9 10 142 135 148 160 * These numbers represent sixteenths of an inch. Proposed Improved Standards. It has been proposed to make a closer segregation of sizes than is made by this standard. Some picklers advocate a series of size-grades differing by 1 sixteenth. This would result in an over-lapping of the grades that would be a source of confusion. Olives of the same weight would go into different grades according to their shape. An elongated olive would go into a lower grade than a rounded olive of the same weight. A somewhat flattened olive would go into a higher grade than a round olive of the same weight. There will of course be a certain amount of this over-lapping, whatever the standard adopted, but it will be negligible with a size-difference of 2 sixteenths, but considerable with one of 1 sixteenth. A more perfect and logical grading would be one that was based, not on an absolute difference of diameter between the size-grades, but on a percentage difference. If the largest grade was the same per- centage larger than the second largest, as this was than the third largest, and so on, the result would be a closer grading of the smaller .sizes where it is most needed. For example, an olive with a diameter of 8 sixteenths weighs only 70 per cent as much as an olive of sixteenths, while an olive of 15 sixteenths weighs 82 per cent as much as an olive of 16 sixteenths. In the first case the difference is readily perceptible to the eye; in the other, it is hardly noticeable. A grading based on a percentage differ- ence avoids this difficulty. Such a grading is shown in Table IX. Designation Fancy Retaining screen 15.0 Average diameter of Olives 16.0 Difference between grades Extra large 13.2 14.1 1.9 Larsre 11.6 12.4 1.7 Medium 10.2 10.9 1.5 Small . 9.0 9.6 1.3 224 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION TABLE IX PROPOSED STANDARD FOR SIZE-GRADES (Based on a percentage difference) Average number per Ib. Mission Other varieties 35 32-39 51 46-57 75 68-83 111 100-124 162 146-180 By this method the difference between grades gradually increases from 1.3 sixteenths between the smallest grades to 1.9 sixteenths between the largest. Each grade has almost exactly 88 per cent the average diameter of the next larger grade and weighs 68 per cent as much. The number of olives to the pound would be inversely proportionate to the weight and the number for each grade would be 68 per cent of the next smaller grade. This method of dividing the size-grades would, from many points of view, be preferable to those now in use. It apears to be as close a grading as is possible in view of the irregularity in the shape of olives of all varieties. It would insure a closer grading than the present system. Olives about 9 sixteenths would be separated into five size- grades, instead of into four, as is the present custom. PEOPOSED SIZE-GRADES FOR OLIVES 1. Fancy. All which are retained by a screen of 15 sixteenths mesh. Average diameter of olives, about 16 sixteenths. Average weight for Mission variety, 35 to the pound. 2. Extra Large. All which pass a 15 but fail to pass a 13.2 six- teenths mesh. Average diameter of olives, 14.1 sixteenths. Average weight for Mission, 51 to the pound. 3. Large. All which pass a 13.2 but fail to pass an 11.6 sixteenths mesh. Average diameter of olives, 12.4 sixteenths. Average weight for Mission, 75 to the pound. 4. Medium. All which pass an 11.6 sixteenths, but fail to pass a 10.2 sixteenths mesh. Average diameter of olives, 10.9 sixteenths. Average weight for Mission, 111 to the pound. 5. Small. All which pass a 10.2 sixteenths, but fail to pass a 9 sixteenths mesh. Average diameter of olives, 9.6 sixteenths. Average weight for Mission, 162 to the pound. SIZE-GRADES FOR RIPE OLIVES 225 Some of the best size-grading machines for olives do not make use of perforated screens but of tapering or adjustable slots. It is possible to adjust such a grader to any standard of sizes. Some picklers adjust the grader so that it divides the olives into size-grades having each a specified number of olives per pound. In one factory four size-grades are made, having respectively 60, 72, 90, and 120 olives to the pound. For Mission olives these numbers represent average diameters of 13.3, 12.4, 11.6, and 10.6 sixteenths, or DIFFERENCE TWO 16 THS. IN. DIFFERENCE 88 PER CENT IS 13 11 X^^v FANCY 15 EXTRA LARGE 13.2 LARGE 11.6 MEDIUM 10.2 SMALL Fig. 2. Comparison of the most usual present system with the proposed system. Right column: Four size-grades of most common present system. Left column: Five size-grades of proposed percentage system. The numbers in the circles show the average diameter of the olives; the numbers at each side show the diameter of the holes in the sorting screens. 226 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION the grading that would be obtained by screens of 10, 11, 12, and 13 sixteenths of an inch. The objections to this close grading have already been shown, and also to the adoption of an absolute difference instead of a percentage difference. COMPAEISON OF VARIOUS SYSTEMS OF SIZE-GRADING A. Size-grades differing by 2 sixteenths of an inch. B. Size-grades differing by 88 per cent in diameter and 68 per cent in weight. C. Nearest approximation to system B that can be made with screens differing by thirty-seconds of an inch. DIAMETER OF PERFORATIONS OF SCREENS (in sixteenths of an inch) A 15 13 11 9 B 15 13.2 11.6 10.2 9 C 15 13 11.5 10 9 DIAMETER AND WEIGHT OF OLIVES OF EACH GRADE UIAM JV1 CjCi A IN U VV -CjUjXl 1 UJ \_/^i V EtQ Average diameter ur i^Aijn vjrn.AU& No. of Olives per Ib. A. A r " A B \ A B C 16 16 16 Fancy 35 35 35 14 14.1 14 Extra large 52 51 52 12 12.4 12% Large 82 75 77 10 10.9 10% Medium 142 111 114 9.6 91/0 Small 162 166 <9 9 9 Culls SUMMARY AND CONCLUSIONS 1. The separation of olives into size-grades is necessary for the best results in pickling and marketing. 2. No standard has been established for size-grades. 3. There is much lack of uniformity in present practice. 4. Some picklers simply eliminate all small olives, usually those whose shortest diameter is less than 10 or 11 sixteenths. Other picklers divide the olives above 9 sixtenths into three or four grades differing by 2 sixteenths. 5. Some picklers consider that this grading is not fine enough and advocate grades differing by only 1 sixteenth. 6. A difference of 1 sixteenth is unnecessarily fine, as adjoining grades would be almost indistinguishable, especially with the larger SIZE-GRADES FOB RIPE OLIVES 227 sizes. This small difference is also impracticable owing to irregu- larities in the shape of the olives. 7. A grading based on any absolute difference between all sizes is imperfect. If suitable to the larger sizes, it will be too coarse for the smaller; if suitable for the smaller, it will be too fine for the larger. 8. A more suitable grading would be one based on a percentage difference; one in which each size was a certain per cent of the next larger size. 0. A grade based on a difference in diameter of 88 per cent is pro- posed. This would increase the number of size-grades above 9 six- teenths from four, which is usual now, to five. Tt would decrease the absolute difference between the smallest sizes to 1.3 sixteenths, while that between the largest sizes would be 1.9 sixteenths. 232992 REPORTS 1897. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viticultural Report for 1896. 1902. Report of the Agricultural Experiment Station for 1898-1901. 1903. Report of the Agricultural Experiment Station for 1901-03. 1904. Twenty-second Report of the Agricultural Experiment Station for 1903-04. 1914. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1913-June, 1914. 1915. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1914-June, 1915. BULLETINS No. 168. 169. 174. 177. 178. 184. 185. 195. 197. 198. 203. 207. 208. 211. 212. 213. 216. No. 65. 69. 70. 76. 80. 83. 100. 106. 107. 108. 109. 110. 111. 114. 115. 117. 118. 119. Observations on Some Vine Diseases in Sonoma County. Tolerance of the Sugar Beet for Alkali. A New Wine-Cooling Machine. A New Method of Making Dry Red Wine. Mosquito Control. Report of the Plant Pathologist to July 1, 1906. Report of Progress in Cereal Investi- gations. The California Grape Root-worm. Grape Culture in California ; Improved Methods of Wine-making; Yeast from California Grapes The Grape Leaf-Hopper. Report of the Plant Pathologist to July 1, 1909. The Control of the Argentine Ant. The Late Blight of Celery. How to Increase the Yield of Wheat in California. California White Wheats. The Principles of Wine-making. A Progress Report upon Soil and Climatic Factors Influencing the Composition of Wheat. No. 220. Dosage Tables. 225. Tolerance of Eucalyptus for Alkali. 227. Grape Vinegar. 230. Enological Investigations. 234. Red Spiders and Mites of Citrus Trees. 241. Vine Pruning in California. Part I. 242. Humus in California Soils. 244. Utilization of Waste Oranges. 246. Vine Pruning in California. Part II. 248. The Economic Value of Pacific Coast Kelps. 249. Stock Poisoning Plants of California. 250. The Loquat. 251. Utilization of the Nitrogen and Or- ganic Matter in Septic and Imhoff Tank Sludges. 252. Deterioration of Lumber. 253. Irrigation and Soil Conditions in the Sierra Nevada Foothills, California. 254. The Avocado in California. 255. The Citricola Scale. 256. Value of Barlev for Cows fed Alfalfa. 257. New Dosage Tables . 258. Mealy Bugs of Citrus Trees. 261. Melaxuma of the Walnut, "Juglans regia." 262. Citrus Diseases of Florida and Cuba compared with those of California. CIRCULARS No. The California Insecticide Law. The Extermination of Morning-Glory. Observations on the Status of Corn Growing in California. Hot Room Callusing. Boys' and Girls' Clubs. The Common Ground Squirrels of California. Potato Growing Clubs. Pruning Frosted Citrus Trees. Directions for using Anti-Hog-Cholera Serum. Spraving Walnut Trees for Blight and Aphis Control. Grape Juice. Communitv or Local Extension Work by the High School Agricultural De- partment. Green Manuring in California. The Use of Lime and Gypsum on Cali- fornia Soils. Correspondence Courses in Agriculture. Increasing the Duty of Water. Grafting Vinifera Vineyards. The Selection and Cost of a Small Pumping Plant. The County Farm Bureau Winery Directions. 121. Some Things the Prospective Settler Should Know. 122. The Management of Strawberry Soils in Pajaro Valley. 124. Alfalfa Silage for Fattening Steers. 125. Aphids on Grain and Cantaloupes. 126. Spraying for the Grape Leaf Hopper. 127. House Fumigation. 128. Insecticide Formulas. 129. The Control of Citrus Insects. 130. Cabbage Growing in California. 131. Spraying for Control of Walnut Aphis. 132. When to Vaccinate against Hog Cholera. 133. County Farm Advisor. 134. Control of Raisin Insects. 135. Official Tests of Dairy Cows. 136. Melilotus Indica. 137. Wood Decay in Orchard Trees. 138. The Silo in California Agriculture. 139. The Generation of Hvdrocvanic Acid Gas in Fumigation by Portable Ma- chines. 140. The Practical Application of Improved Methods of Fermentation in Califor- nia Wineries during 1913 and 1914. 141. Standard Insecticides and Fungicides versus Secret Preparations. 142. Practical and Inexpensive Poultry Ap- pliances. 143. Control of Grasshoppers in Imperial Valley. ; ;Y of CALIFORNIA AT LOS ANGELES URRARY SB 367 Bioletti - I52a Size cop. 4 for ripe A 001 095413 9