268 Report OF THE HorTICULTURAL DEPARTMENT OF THE 
The abnormally large percentage of injured fruit on the 
I-1-50 tree sprayed during rain is wholly unexplainable — one 
of the anomalies of bordeaux injury. So, too, the very low 
percentage of injured fruit on the 4-8-50 trees sprayed during 
dry weather is unexplainable. In the latter case the low per- 
centage comes from the fact that the fruit on one of the two 
trees in the plat showed almost no injury. 
The figures in these two tables show that in all except one of 
the 16 sprayed plats, the injury was greatest on the trees sprayed 
during rain, and in the exception the difference is but 0.4 per 
ct. If we average the percentages of injured fruits in the two 
tables, the figures are, 15.3 per ct. for the trees sprayed during 
rain, and 7.6 per ct. for those sprayed during dry weather, or 
a little more than twice.as great injury in the former as in the 
latter. 
The results of the experiment emphatically confirm the opin- 
ions of the fruit growers who have suffered from bordeaux in- 
jury that wet weather gives the favoring atmospheric conditions 
for this trouble. In the survey of the injury for 1905, 57 men 
out of 69 who had had experience with the injury that year, 
gave wet weather as the favoring condition. The results agree 
with the opinion of all the horticulturists of experiment stations 
of other states who had knowledge of bordeaux injury.“ They 
agree, too, with those of various experimenters in studying simi- 
lar injury from bordeaux mixture on other plants; thus Bain™ 
in his work with peaches; Muth® with grapes; Schander® with 
beans and peaches; Sorauer® with potatoes; Mueller® with 
peaches; have all found in their experimental work that meteoric 
moisture gives a favoring condition for bordeaux injury. 
The first experimenters with bordeaux mixture frequently 
make note of the deletérious effect of falling rain on the ad- 
hesive properties of the mixture. Much attention was given in 
the early days of spraying to securing a mixture that would 
stick and not disintegrate and wash away; molasses, soap, sugar 
and other substances were added to increase its adhesive power. 
Rain, without question, dissolves and washes out to some ex- 
tent the fungicidal ingredients of the bordeaux mixture. The 
conclusion was long ago reached, however, that this effect is 
comparatively insignificant and the washing effect of rain on 
bordeaux mixture is now but little considered.. The influence 
* See letters, pp. 228-232. 
“Bain (4). “Muth (46). “Schander (53). “Sorauer (54). “ Mueller. 
(45). 
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