FLORIDA STATE HORTICULTURAL SOCIETY S9

Length of exposure-4~ minutes.Prior to dyeing oranges were washed in solu­tion of borax, soda ash, and Zelnor's No. 10with Wyandot detergent added.

Wax treatment-Food Machinery cold wax.

Treatment B.Dye-Aqueous solution of a proprietary non­

certified food color.Temperature of dye-12S0 F.Length of exposure-7~ minutes.

Wax treatment-"Hales water wax emulsion."

Treatment C.Dye-Aqueous solution of certified food color

dye (yellow OB and yellow AB).

Temperature of dye-1l4° F.

Length of exposure-4~ minutes.·Prior to staining oranges were washed intank with soda ash solution at 880 F.

Wax treatment-none.

AMOUNT AND CHARACTER OF APPLICATIONS

Soil applications continue to give unsatisfactoryresults in the citrus belt. Applications of S to 15pounds per tree on badly frenched trees broughta slow response in most cases. The response,however, could not be compared with that ob­tained from one spray applied in the spring.Smaller soil applications have not given good re­sults and there are some indications that largerapplications may damage the trees. Spraying is

PROGRESS IN ZINC SULPHATE STUDIES

A. F. Camp, Horticulturist, and Walter Reuther, Laboratory ABBistantAgricultural Experiment Station, Gainesville

It is not our intention to give a detailed re- TIME OF APPLICATION

port on the zinc studies at this time. what re- In the experiments to determine the best timemarks are made will be primarily an introduction of application we have found this related to theto a field trip to our experimental plots. This condition of the tree. Sprays put on just beforetrip will follow this session and we hope that a flush bring a strong response with the appear­those interested will be able to go. ance of the flush, whereas sprays put on after

Before entering into a discussion of the work the fall flush do not show very satisfactory re­we wish to stress one point which was made last suIts until the following spring. In general ityear, namely that zinc salts are useful in the cor- may be said that the best results were obtainedrection of frenching or mottle leaf of citrus, but from applications from February 1st to July 1st,so far have not been found valuable in the treat- and less satisfactory results during the latter halfment of other troubles of citrus. The zinc suI- of the year. This was probably accentuated lastphate is recommended for trial in cases of true year by the very dry weather in the central partfrenching but at this stage is not recommended of tlie state so that there was practically no fallfor so-called bronzing or copper-leaf and other flush in the groves used in that area. At Verotroubles. This warning has been made necessary Beach, however, August sprays showed a definiteby the great interest shown in the use of zinc response on the fall flush.salts with the result that they have been assigneda great many virtues which they do not, in reality,possess. This is to be expected when any' newremedy is made available, but at the same timethe g-;'ower should take care to inform himselfconcerning the actual results of research work andto utilize the treatment only as recommended or elseto apply it in only a limited way for experimentalpurposes. Zinc is distinctly not a shotgun remedyand should be used only on the basis of the ~etual

research work to date.

60 FLORID'A STATE HORTICULTURAL SOCIETY

still the only recommended method of applicationfor citrus.

A considerable amount of experimenting wasdone last sum~er in an effort to determine theconcentration of zinc necessary to give results insprays. The results of much of this work wereunsatisfactory due to the dry weather and the De­cember freeze. As a result of the latter a num­ber of plbts had to be abandoned before the workwas complete. Other experiments, however, arcnow under way and we hope by next year toindicate definitely the contentration necessary toproduce results with one or more sprays, andalso to answer the question of frequency of ap­plications. So far as the few uninjured (bycold) plots were concerned it appeared that onespraying per year was about as good as two ormore.

A considerable amount of work is being doneon the form of zinc in the spray. While the zinc­lime spray was used in most of the early ex­periments much wor~ is being done this yearwith zinc sulphate in lime sulphur, Bordeaux inix~ture and oil emulsions and also with some com..tnercial sprays made up by allowing zinc salts toreact with lime, arid the~ drying the p~ecipitate.The latter sprays are used in the control of bac­teriai spot of peaches and are compar~tively sim­pie to use. The whole problem of the type ofspray is tied up with problems of insect and dis­ease control. Does the addition of zinc sulpha~e tolime sulphur reduce its value as an insectici~e~

does zinc-lime kill friendly fungi and consequentlybring on scale infestations, does zinc help in the:c'~ntrol of scab and melanose? The assistanceof the Pathology and Entomology Departmentshas been solicited for this work and we believethey will be 'able to check a11 plots this year andhelp to answer these perplexing q'uestions whichhave a very considerable bearing on the recom­mendations to be made. This work is at! in

.progress and if things go well this year detailedreports should be forthcoming next year that willclear up many of these points.

·For the present the following spray is recom­mended for use on frenching:

5 Ibs. 89% zinc sulphate.

2~ Ibs.. high grade hydrated li~e.

50 or 100 gallons of water (100 gallons for lightcases of frenching).

After consiperable experience last year the fol­lowing suggestions are given for making the abovespray. I

1. If the zinc sulphate is lumpy screen dryand pulverize ail lumps.

2. Fill sprayer one-half to two-thirds full ofwater.

3. Start agitator and add zinc sulphate veryslowly--do not use the screen.

4. Screen in lime and spreader with water•.5. Use the spray immediately.For a zinc-lime sulphur spray make up a 5-2~­

100 zinc-lime spray as above recommended and addlime...sulpliur solution last. The use of zinc sul­phate hi time sulphur without the addition of limeis not recommended at present as it throws downtoo much sulphur and may affect the insect kiD.

For Bordeaux with zinc sulphate added, we havehad succe~s with a" spray made up as follows:

2 Ibs. copper sulphate4 Ibs. hydrated lime2 Ibs. zinc sulphate.

Make up as a regular Bordeaux using the cop­per sulphate and all of the lime and then add thezinc sulphate slowly with the agitator running.You will note that sufficient lime is added to sat­isfy both the copper sulphate and the zinc sul­phate. The fungicidal value of this remains tobe determined and too much dependence shouldnot be put on it for the control of mel~nose..

Considerable work is in progress on the effectof zinc sprays on the fruit. This work covers tooshort a period to be of authoritative value, butsome trends are of considerable interest. Thefruit on badly frenched trees is usually small,hard in texture, low in juice and very low in acid.Not infrequently it is badly ammoniated ana whenthis is "the case the amount of nitrogen in the pulpis abnormally high. Analyses of fruit from treessprayed last summer showed that the use of zinc,even after the fruit was set, increased the acidand juice content material and while it did noteliminate the symptoms of ammoniation that werealready present, it did not reduce the amount of

FLORIDA STATE HORTICULTURAL SOCIETY 61

nitrogen in the pulp. While such fruit was notexactly normal in composition the changes wereall in that direction. Much information along thisline will be accumulated this year on crops setthe year following spraying. The effect of zincsprays on maturity and color is particularlyim­portant and is being intensively studied.

In the trip to the experimental plots this after­noon we wish to call attention to several points.The layout is not easy to look over as the area inwhich frenching was sevete was very irregular,and consequently treatments do not show up as

well as they do in other groves which were en­tirely frenched. A central point has been se­lected where effects of sprays and soil treatmentcan be seen to best advantage and the trees prop­erly labelled. We wish to call attentiolt to thefact that leaves which were frenched, when thespray was put on, have turned green but have notgrowrt appreciably in size, that the new growthis both 'green and normal in size, that soil treat­ment gave fair results; also note that one spray­ing was apparently as effective as two sprayings.Other results will be self-explanatory.

CITRUS FRUITS I~ NUTRlTIO~

Dr. Quida Davis Abbott, GaiDes'rille

Over the servmg counter in a Dutch grill atthe University of Pennsylvania there is this in­scription in Pennsylvania Dutch, "Sak mir was duesscht und Ich s;Uc dir was du besscht." Whichin Pennsylvania Dutch is the equivalent for theold maxim, "Tell me what you eat and I will tellyou what you are."

I think it might Ire posSible to go even furtherand say,"Tell ine what you eat and I will tellyou what you do, whether you are a man orwoman, girl or boy, and how old you are: Arecent writer has divided the human life intoeleven gastronomic ages which are as follows:1. milk; 2, milk and bread; 3, milk, bread, spin­ach and egg; 4, oatmeal, butter, pop corn, and allday suckers; 5, ice cream soda and hot dogs; 6,minute steaks, French fried potatoes, coffee, andapple pie; 7, bouillon, roast duck, escalloped po­ta1oes, French rolls, broccoli, fruit salad, divinityfudge, demi tasse; 8, pate de Ioies gras, potatoesparisienne, egg plant a la opera, mince pie, Roche­forte cheese, coffee; 9, soft boiled eggs, toast, milk;10, crackers and milk;11, milk.

Thus life comes to a close as it started-onmilk. What has happened during the years?What have we done to our digestive tracts? Alasin many cases we don't know. A study of the

" • ..~ _" I ",

diets of Americans made at the beginning of theWorld War. shows that Americans are misfedrather than underfed. At the present there areindications that America is becoming diet con­scious. What has been responSIble for this?

One of the firit reasons is that during the warwhen the conservation and substitution of foodwas necessary it was found that diets adequate incalories and protein, were still not adequate in foodelements necessary for 'health and well-being.This opened up a new line of investigation-vi­tamin research. The discovery of the qualita­tive differences in diet led to the study of de­ficiency diseases and much light was thrown oncertain diseases which up 'to that time 'had beenwrapped in obscurity. Beri beri, polyneuritis,scurvy, xerophthalmia, rickets, were all foundto be preventable and !=urableby diet. This wasa great step forward and led to the study ofother diseases whose etiology is unknown, suchas peptic ulcer, diabetis, neuphritis, gall stoneS.hyperacidity, aild others which respond more orless to diet.

Furthermore, the depression has made it neces­sary to feed large groups of people and it has-,been recognized that well fed people are content,that anarchy and revolution do not flourish amongpeople that are well nourished. The best way to-'