450 ANNUAL, REPORT OF THE Off. Doc. 



the individual flower buds. The first treatment should be made 

 after this occurs and when the individual flower buds are exposed 

 so as to catch the spray. The second treatment should be made 

 as soon as the petals have fallen, or while the last petals are drop- 

 ping. The third should be made seven or ten days later. The 

 fourth two weeks after the third, and the fifth two weeks after 

 the fourth. This treatment is so expensive and requires so many 

 sprayings that it is only practicable in orchards that are otherwise 

 successful and where good crops of fruit are at stake. I saw an 

 orchard in Western New York this season of 600 trees that was 

 given practically this treatment and the fruit from these 600 trees 

 was sold for |7,480, delivered on the packing benches. There is 

 little likelihood that any variety of apple may be so severely at- 

 tacked in this country as to require full treatment. The question then 

 comes up in each locality and with each particular variety as to 

 what treatments should be left out. Naturally the grower wishes 

 to spray as little as possible and secure commercially successful re- 

 sults. Ordinarily the first and second treatments are the most im- 

 portant. Probably in this country most of the infection is the early 

 form of scab, preventable by these early treatments. The second 

 treatment, just as the petals have fallen, comes at exactly the right 

 time for the first spraying for codling moth. This spraying is in 

 fact necessary against this insect so that with the addition of arsen- 

 ate of lead or Paris Green to the Bordeaux mixture is accomplishes 

 both purposes. In fact this spraying is so important for the codling 

 moth that it may be considered that the Bordeaux mixture is being 

 added to the arsenate rather than vice versa. (I mention this in- 

 secticide incidentally as a part of the orchard scheme of spraying, 

 but wish to say that my own investigation work in the Bureau of 

 Plant Industry does not include insects and their treatment. This 

 is the work of the Bureau of Entomology.) In the same way a 

 later treatment for codling moth is desirable about three or four 

 weeks after the petals fall. This brings it up to the time of treat- 

 ment No. 4. It is, therefore, particularly desirable to make a spray- 

 ing at about the time of No. 4 with the combined Bordeaux mix- 

 ture and arsenate of lead. The standard formula for this mixture 

 can be considered as 5 lbs. blue stone, 5 lbs. lime and 50 gals, of 

 water, to which should be added about 2 lbs. arsenate of lead. 



Where apple bitter rot occurs, later treatments are required, 

 beginning about the time of No. 5, and three or four treatments, 

 according to the severity, at intervals of from two to three weeks 

 during the summer are necessary for the prevention of this disease. 

 I believe, however, this is not common in Pennsylvania. 



Apple Leaf Blight. 



The apple leaf blight caused by various fungi, particularly that 

 caused by Sphaeropsis malorunu is very common in this vicinity. 

 This is very easily prevented. Where this disease occurs alone and 

 to be treated individually, one or two sprayings with standard Boi> 

 deaux mixture will suffice. Where a single treatment is made, it 

 should be about 30 days after the petals fall and when the trees arc 

 in full leaf. Where two treatments are made, the first should be 



