UNIVERSITY OF CALIFORNIA. AGRICULTURAL EXPERIMENT STATION. BERKELEY, CAL. if. W. HILGARD, Director. BULLETIN NO. 96. ^-SULPHURING IN FRUIT DRYING. fi-FIG TREES AT THE EXPERIMENT STATIONS. C-NOTES ON PERSIAN PALMS. SULPHURING IN Of late several papers in this State have discussed the subject of the use of the sulphuring process in fruit-drying, some prefacing their articles with the remark that I had " issued another proclamation" on the subject. I am unable to remember having uttered anything in public relating to the subject since the publication of Bulle- tin No. 86, eighteen months ago. Since, however, the articles alluded to bring the matter forward, and imply a partial miscon- ception of my views, and of their true basis, I think it proper to put them on record once more. Sulphurous gas, which is formed when sulphur is burned, is well known, and con- stantly used as a disinfecting, bleaching and deodorizing agent, second in virtue only to chlorine. The fact that it is the agent offi- cially used in the disinfection of infected f RUIT DRYING. houses, ships and individuals is conclusive on these points. It is therefore idle to pre- tend that sulphuring does not diminish the flavor of fruit or of anything else touched by it. It is perfectly certain that it does so; and the only debatable question is the ex- tent to which it may be used for bleaching fruit without any material detriment to the flavor. It is in evidence that a reasonable amount of bleaching can be done by applying the gas to the freshly cut fruit without injuring the flavor to a material degree, since the flavor will penetrate from the inside out- ward to a sufficient extent to compensate for the loss of what naturally belongs to the bleached exterior portion. The limit, however, is a narrow one, and it is so frequently exceeded in practice (whether intentionally to secure " extra lteht " color to attract the un wary purchaser £?h State that produces it and ill cajcu- lated to insure a permanent demand. Ihia s especially true of the thinly sliced apples and pears, which are quickly penetrated by the gas and assume a greenish-white tint that, while it may be inviting to equally " green " purchasers, assures the expert that the natural flavor is practically gone, lhe producer himself declines to put them on his table, but the dealer and the public, as at present informed, are willing to pay an extra price for it. This demand for unnat- urally light-colored dried fruit is a fad like manv others, which will have its day but will inevitably give way, in the course of time, to a preference for the better- flavored product having the tint which in- sures its being so. So long as the "fad" lasts, so long will producers or dealers sul- phur the fruit to suit the eye rather than the palate of the consumer. It certainly seems desirable to hasten the advent of a more rational state of the public mind on this point; quite apart from the sanitary consideration, which, if not of primary im- portance as regards most of the sulphured fruit now in the market, has nevertheless proved sufficiently potent to cause the prac- tice of sulphuring to be legally prohibited in the old world, where therefore our fruits so treated would fall under the ban of the law. An additional consideration is that this process permits of rendering third and fourth cLs fruit equal in appearance to the best and is therefore easily used for fraudu- ler 4re P thus seems to me to be abundant cause for desiring, and working for, he abatement of the public delusion on he Set Of light-colored dried fruit which sacrifices the'substance to the shadow and is certain, in the end, to inure to the detri- ment of our dried-fruit trade. The ove - sensitiveness that has of late manifested it- self in respect to the maintenance ot my position in the question seems, therefore, to be ill-founded. I hope to find a measurably unobjection- able substitute for the uncertain process as now practiced, in the use of a solution of " bisulphite of soda" (heretofore sold under the name of " California fruit salt") of definite strength, into which the cut fruit can be dipped before drying. In this process, the same agent (sulphurous gas) is employed in the liquid form, but so con- trolled as to the amount used that the chances of overdoing the sulphuring— now so great because of the convenience with which the fruit can be left exposed to the sulphurous gas for an indefinite time — would be reduced, to a minimum. The compound can be produced very cheaply, and the solution used will be very weak. The exact strength and time required to produce the best results with different fruits will form the subject of experiments at the station during the coming fruit season. E. W. Hilgard. s FIG TREES ftT TJHE EXPERIMENT STATIONS. The fig promises to become one of the years, when all the varieties being grown most important fruit trees of Cilifornia. are in bearing, the comparative value of the But the culture of this fruit belongs chiefly fruits can be tested. At present the prob- to the borders of the Mediterranean, espe- lem of hardiness requires attention, cially Asia Minor, and much less is known here about varieties and their treatment FIGS AT THE SAN Joaquin station. than is the case with the more common de- ^ Q December 17th and 18.h I examined ciduous fruits. The numerous discussions tne growth of the fig trees at the Bail Joa- upon the fig, in recent years, prove the ex- * temperature as any other part of list shows the varieties now growing and the San Joaquin vail »y growing, studied in the preparation of this report Gros Gris Bifere. Ag n. Angelique. Abondance precoce. Brianzola. Black Ischia. Brunswick. Black Boiirjassotte. Black Marseilles. Ba-nasotte Grise. Brown Ischia. Brown Turkey. Black Brogiatto. White Brogiatto. California Black. Col di Signora Nero. Drap d'Or. Dalmatian. Doree Narbus. De Constantine. Du Roi. White Dattato. Black Dattato. Early Violet. Guigliono. Grossale. Grizzly Boiirjassotte. Hirtu du Japon. Ladora. Monaca Bianca. Negra Larga. OAorne Prolific. Pasteliere. Royal Vineyard. Ronde Noire. Ronde Violette Hative. Raby Castle. Rocardi. Rubrado. Smyrna No. 1. Smyrna No. 2. Smyrna No. 3. Smyrna, Wild. San Pedro. Sanvito. Trojano. White Boiirjassotte. White Genoa. White Adriatic. White Marseilles. There seems to be a basin about the lake into which the cold air settles, and it is doubtful whether rows of forest trees will be of as much service here as in some other localities where the cold is due to air currents that may be broken. The fig trees at this station were mostly planted in the winter of 1888-89. Some died, having been set in alkali spots, and were replaced. The worst situations have now been treated with gypsum, ab ut 10 pounds having been put around each tree. Owing to the differences of soil, a very great difference in the growth of trees of the same age is manifest. This of course is compli- cated with the difference naturally belong- ing to the growth of different varieties. About 12 of the varieties of fiors represented bore fruit last season (1891.) Du Roi, a new variety little known in the State, was one of the best of these, and attracted much atten- tion. All the fig trees received some irrigation, but not a drop of water was allowed them The first season after the figs were planted after August. The first heavy frosts in No at the different stations, many differences in vember took off all the leaves. The wood growth and in adaptation to climate began appeared well ripened in most cases, except, to be noticed. The varieties showed a as usual, the extreme tips of " water sprouts" greater range of variation in respect to their and late growths. It was therefore a sur- power to resist cold than any other semitropic prise to the foreman when some of the trees fruit. The problem that naturally presented showed the effects of the early December itself was this: How do the various sorts frosts (temperature 22°). Certain varieties compare in point of hardiness and relative appear to suffer, and it does not seem to be endurance? The colder districts of the a question of alkali or cold currents; for, as State desire to grow figs, if possible, and previously stated, the whole tract is subject need the varieties that are most hardy, to identical conditions in this regard. Be- Then, also, we may expect to produce still sides, trees of the same kind, one of which more hardy seedlings from hybrids of certain stands on sandy soil and the other on sorts, or by fertilizing the finer table figs "alkali," seem to suffer to a similar extent, with the wild Smyrna. In a few more Of the older varieties (older in point of introduction to this State), the California Black is not to be ranked as high in the matter of hardiness as was to be expected. It can only be called "medium"; the White Ischia stands somewhat better; the Dalma- tian does fairly well; the Black and White Marseilles, which unfortunately are rather small for table use or for drying, do even better than the Dalmatian. The San Pedro, a fine table variety much liked by growers, suffers greatly, even branches of half an inch thickness being frozen. The two Smyrna varieties have stood the frost well. The Brown Ischia has suffered more than the Black California. The three Bourjas- sottes, black, white and green, together with the White Adriatic, are able to withstand the cold. Among the newer varieties, the Du Roi, previously alluded to, is one of the most hardy. Ladora, an excellent fig, is badly frosted, but not enough to justify discarding it as yet. Col di Signora Nero is so much frozen that it must be cut back nearly to the ground next spring. One of the worst cases in the avenue is that of the Gros Gris Bi- fere, which is certainly not hardy enough for the station. Ronde Violette Hative is a fine fig, but slightly frosted, and probably safe when older. De Constantine and Drap D'Or have done well. Abondance Precoce suffers a little; Royal Vineyard ranks but medium. The most hardy fig at the station, and the only one that shows no sign of frost anywhere, is the Doree Narbus, one of the new importations. There are two trees of this variety in different parts of the grounds, ore in alkali, the other (near the orange trees) in sandy soil. It has compact growth, hard, dark bark, short joints and small buds. The leaves are dark and rather small. It has not yet fruited, hut if it proves to bear well and to be of fine quality, it can be recommended for frosty situations. To sum up these observations, there are two or three sorts being tested that seem unlikely to stand the climate. Possibly ten sorts show appreciable loss of young wood. All the others, except the Doree Narbus, show some slight effect of frost upon the soft, late growth, but not, except as above noted, enough to effect their orchard value to the region. FIGS AT POMONA STATION. The fig experiment at the Southern Cali- fornia Station, near Pomona, is less ad- vanced than any other, since trees were only planted there last spring. It was hoped that all the varieties would prove hardy at Pomona, and at first it .appeared that they would do so. But this month, January, many varieties have suffered from frost. The complete comparison with Tu- lare and Paso Robles cannot yet be made, for the list of varieties is incomplete at Po- mona. But the following sorts proved "hardy:" Du Roi, Monaca Bianca, Hirtu du Japon, Agen and Col di Signora Nero. This shows that more varieties out of the complete list of 51 will thrive at Pomona than at Tulare or Paso Robles. Twelve va- rieties, mostly new, and very small trees with immature wood sent to the station for growth for a year in nursery rows, were se- verely frozen, in some cases M nearly to the ground." This, however, is not evidence against future success with many of these varieties. The following trees suffered much from frost, and are probably unreliable in that part of the valley; Grosse Grise Bi- fere, Grizzly Bourjassotte, Ronde Violette Hative, and Negra Larga. FIG TREES AT PASO ROBLES. At the Southern Coa3t Range. Station, near Paso Robles, where the same varieties of figs are growing, the problem is further complicated by the fact that there is much difference in the soil and location of the trees, the avenue passing through a low swale that is much more frosty, and has a more compact soil, than the rest of the tract. Most of the trees were planted at the same time as those at the Tulare station. They received no irrigation. Those in the most exposed positions were wrapped in straw to protect them. January 4th the straw was taken off so as to make a thorough examination, and put back again. Among the tiers on the high land were the Black and the White Bourjassottes, the two varieties of Smyrna, Ronde Noire, Bruns- wick, Col di Signora Nero, Angelique, White Ischia, Agen and Pasteliere. All did fairly well, except the White Ischia, which was badly frosted. At Tulare also the White Ischia was more tender than the Bourjassottes. The only marked difference between the two stations in this group was in the case of Col di Signora Nero, which nearly escaped frost at Paso Robles, but was very badly frosted at Tulare. Continuing along the avenue toward the swale, under less favorable conditions, White Adriatic, as at Tulare, proves fairly hardy, and grew well. A small tree planted in 1890-91 suffered somewhat. The Dalmatian was only a little touched with frost. Drap d'Or, on quite low ground, suf- fered much. De Constantine, as at Tulare, made a strong growth and nearly escaped frost. A Smyrna planted in the swale in 1890 gave an opportunity for comparison; it was considerably frosted, but not nearly as much as some other varieties. The Black Marseilles, which did well at Tulare, was "cut right down" to the ground with the cold. California Black, as at Tulare, was not in the front rank, only "of medium har- 5 Brown Ischia, as at Tulare, must be placed below the Black Californian. Early Violet, which did fairly well at Tu- lare, was severely frosted here. Doree Nar- bus, the most hardy of all at Tulare, "with- stood the frost," though in one of the lowest and most exposed situations, but "has grown little." Hirtu du Japon was also hardy. Grosse Grise Bifere, which was one of the most badly frosted sorts at Tulare, was also very severely frosted here. So was the San Pedro and the Monaca Bianca. The last three were on adobe soil. The foreman, Mr. R. D. Cruickshank, writes as regards the general subject that ''some varieties are on adobe, some in the swale and some on the higher and drier land," as before stated. He adds: u The kind of soil they occupy has much to do with the maturity of the shoots in autumn and their ability to withstand the frost. I notice that those on the hi^h ground have always suffered least, while none of them have been very severely frosted this year." The thermometer went down to 18 degrees one night this season and to 20 degrees on another. The figs have been touched regu- larly with frost every spring and fall since they have bet n planted, and on the whole have not done very well: " They do not oc- cupy a very good piece of land, and at first had a hard struggle with the gophers." For this reason it has been decided to remove from the swale thore varieties that do not withstand the frost there and plant them on higher land. The result of the experiment can be summed up in a few words. The fig is not an entire success in this region unless the location is carefully chosen. It must be high and protected from severe frosts. When the swale on the station tract is more fully underdrained, figs will do better there, but it is not the place one would choose for a fig orchard. A tract 200 or 300 feet higher would give better results. For fam- ily planting it would seem that the Smyrna, White Adriatic, Doree, Narbus and several others to which allusion has been made are here among the more hardy sorts. CLIMATIC OBSERVATIONS. This portion of the Coast Range is sub- ject to greater fluctuations of temperature than has been heretofore supposed. The mean monthly temperature can never be used as conclusive evidence of any climate. Nothing could be more misleading in refer- ence to the climate under consideration — a climate representative of many higher val- leys in the California coast ranges. The station is situated 80 feet above the Salinas river, about 800 feet above the sea level and forty miles due east of Estero bay, with a high mountain chain — the Santa Lucia — between. There are many places in the dis- trict where the thermometric variations are even more sudden than at the station. The following table, compiled from Mr. Cruick- shank's weather reports, will show some of the peculiarities of the climate. Especial attention is called to the great daily varia- tion of temperature; also to the sudden changes in relative humidity. The greatest atmospheric dryness in October and Decem- ber occurred when a north wind was blow- ing. The hvgrometer was exposed on the north side of the house, so that the condi- tions were favorable to extreme indications, but in any case the record is an extraordi- nary one. So far as human sensations are concerned this very atmospheric dryness serves to soften materially the impressions of the temperature variations. METEOROLOGICAL TABLE SOUTHERN COAST RANGE STATION. December. CM O CO CO CO O CM v -'. November- o«>oco m to : CO lO CM CM CO O ; oi c> oi * .-I co -*t< co © : CM SN CN lO C? W O - ,_, CO O CO ■** CO CO TJ< 29 23 29.41 29.10 .31 70.79 112 42 70 52 23 38.86 • CM tO rH . co " £; 22 ^ itM** ifeM*** 01 ass a February... 29.26 29*63 28.40 1 25 49.38 64 30 34 28 2 17.50 . 7.29 77 86 69 i 17 January.. In CM CM « © W O :»-<»- : : a si : : d m : efl* 3 P 3d !5 © © I 2 2 » 8 £ j © e Dumber of letters of inquiry received makes some additional notes upon the present con- dition of the palms desirable. The palms are planted at Pomona and at Tulare. The larggr number of varieties and in some respects the best plants were sent to Tulare, as it was thought at Washington that the climate there would prove more fa- vorable. This expectation does not seem likely to be realized, as several varieties that are more tender than others have suf- fered this winter. Some, however, are eminently suited to the place. At Tulare Station, also at Pomona, the pistillate or bearing palms are planted in a circle, with thestaminate plant in the center. The soil is sandy and free from alkali. Ir- rigation ceased the first of September. Deglet Nour and M'Kintichi prove to be very poor growers, small leaves, hard to root, and not to be recommended unless the fruit is of peculiar excellence. ' These two varieties show similar characteristics at Pomona. The Sultaneh variety, said to be one of the best, is extremely delicate in appear- ance, leaflets slender and fine, growth slow; suffers from frost at Tulare. This variety does better at Pomona, and is certainly one of the most beautiful of all in an ornament- al sense. Amhat, at Tulare, is so badly frosted that it will be advisable to move it to a better locality. When most of the large leaves of a palm are killed, and protection is needed for the heart of the plant, it is evident that no valuable result can follow further experi- ment at that point. This variety at Pomona has so far escaped with only slight injury. It is the most tender of all the Persian palms at the stations. Next to the Amhet is Haraneh, a poor grower, considerably frosted at Tulare, and slightly so at Pomona. Rashedah and Rass show only medium hardiness at Tulare, losing a portion of the upper leaves. Rass is a remarkable variety of very strong growth, leaves large, light green, and beautiful in appearance. The plant at Tulare has already six small suck- ers. It is the only one of all the palrns that has as yet increased itself by division. The difference in rapidity of growth be- tween such varieties as Rass and such as Sultaneh or Deglet Nour, is as great as that between a Bartlett pear tree and a Seckel. One palm at Tulare shows marked hardi- ness. This is Seevah, a compact grower, with small, dark leaves; it is more hardy than the seedling date palms at the station, which latter correspond more nearly in hardiness with such varieties as Rass. In Seevah we probably have a date palm suit- able to all parts of the San Joaquin valley; perhaps three or four more of the twelve va- rieties represented are likely to prove desir- able there. But several, as the preceding notes imply, are not likely to withstand the frosts of the open valley, whatever they may do on the foothills. Referring again to the seedling date palms at Tulare Station for comparison, one observes that all are slightly frosted, while two are badly so. The wild date (P. Canariensis) would undoubtedly stand the same locality and pass unscathed through the severest winter ever known there, but the species date is mere- ly ornamental; and the seedling date offers no advantages in point of hardiness over any, except a few of the named varieties now at the station, while it is distinctly at a disadvantage in comparison with several of the best. A curious fact in connection with the date palms is that the large grasshoppers of the San Joaquin valley attack the leaves with a special zeal. Last summer the grass hoppers left fields of grain, and beds of small cultures representing many species of plants, to settle on the palms and eat holes in the leaves. They could hardly be pre- vented from destroying several varieties for which they showed a strong preference, and they injured nearly all to some extent. Their method of attack is to make dozens of holes, about as large as a dime, in the leaflets. Sultaneh, Rass, and Haraneh are among those that were the most severely in- jured. Thriftiness, or lack of thriftiness, in the plant seemed to make little or no differ- ence with the grasshoppers. The hardy variety, Seevah, they left entirely alone, and it was the only one that escaped attack. At Pomona also the grasshoppers left other plants to attack the palms, and here, as at Tulare, they showed preferences, though less marked, as their invasion was of much shorter duration. There has not been any complaint, so far as I know, that the grasshoppers destroy seedling date palms, or the Canarian date, in any part of California. At the stations, as it happens, the seedling palms were unin- jured, though this was probably owing to their location nearer the buildings than were the named varieties. It is well known that the locusts of the deserts of Asia and Alrica sometimes entirely destroy palm 8 groves, but it is certainly surprising to find that the California grasshoppers prefer the hard, fibrous leaves of the palm to any other green food. The problems of importance, next to the hardiness of different varieties, seem to be: How soon will the plants bear, and how fast can they be propagated by suckers ? When better established, it will be possible to force them into a more rapid division, but this can only be done at the expense of the mother plants. The small number of specimens obtained — only two of any vari- ety and of some only one — precludes the idea of such an early or general distribution as many correspondents appear to expect, Besides, the U. S. Agricultural Dep't has distinctly required the first increase of stock to be heid subject to its orders, at least for the present. Those varieties that promise best can be imported by nurserymen in larger numbers, and easily propagated to supply any future demand. The experi- ment at the agricultural stations fulfils its end, and justifies the cost, whenever those stations have fully tested and reported upon the varieties in their hands. Charles H. Shinx. Berkeley, Jan. 25, 1892.