17 



DEMONSTRATION SPRAYING FOR APPLE BLOTCH IN ARKANSAS. 



The treatment. — As stated above, the apple blotch appeared to a 

 disastrous extent in some of the demonstration blocks. Excellent 

 opportunities were, therefore, afforded for observing the effect of 

 spraying with Bordeaux mixture in the control of this disease in con- 

 nection with the spraying in the Gipple orchard at Bentonville, Ark. 

 One hundred Ben Davis trees, 18 years old, fairly vigorous and in 

 good condition, were used, of which number 24 trees were set aside 

 as checks and left untreated. A block of 100 Winesap trees was also 

 used in the demonstration work, but as the apple blotch did not 

 develop to a serious extent on this variety, only the results obtained 

 on the Ben Davis block will be reported here. 



The trees were sprayed with Bordeaux mixture on May 4 (about 

 four days after the petals had fallen), May 8, June 12, June 26, 

 July 17, and August 4, making six applications in all. This orchard 

 was reached late, and the two early applications were made onl»y 

 four days apart in order to thoroughly poison the fruit for the codling 

 moth before the calyx lobes closed, and for protection against apple 

 scab. The formula of Bordeaux mixture used was 4 pounds of blue- 

 stone and 6 pounds of lime, with the addition of 2 pounds of arsenate 

 of lead, to 50 gallons of water. 



The results. — The crop was picked from September 19 to 27, and 

 the fruit from each of the several sprayed and imsprayed trees was 

 classified according to injury from scab, apple blotch, bitter-rot, 

 black-rot, and the codling moth, the affected apples being counted 

 in each case. The crop from the remaining trees, sprayed and 

 unsprayed, was simply classified as merchantable and unmerchant- 

 able fruit, as shown later (p. 33). The windfalls were included in 

 the counts, so that practically every apple produced by the trees was 

 taken into account. The first count of windfalls was made on August 4 

 in order to get their classification before thej decayed, and the fruit that 

 fell subsequently was classified at the time the crop was harvested. 



The results of the treatments in controlling the apple blotch are 

 shown in Table 5. 



Table 5. — Comparison of sound fruit and fruit affected with apple blotch from S sprayed 

 and .:' unsprayrd Ben Davis trees, Gipple orchard, Bentonville, Arh., 1906. Fruit 

 picked September 19 to 21 . 



27050— No. 283—07- 



