335 
Results .—The orchard was visited and careful notes taken on August 
2 and again on October 12. By August 2 the control plats had lost the 
greater part of their foliage. Scarcely one-fifth remained on these trees, 
and this was rapidly falling, it being badly affected by leaf-blight. The 
contrast between unsprayed and the sprayed foliage was very striking. 
All the sprayed trees, including the single treatments, looked exceed¬ 
ingly well as compared with the controls, except the trees sprayed April 
24. These showed but little improvement over the unsprayed controls. 
The other plats, which had been sprayed once, while appearing to retain 
full foliage, had begun to shed their leaves. There were fewer spots on the 
leaves of the trees sprayed May 15 than on those sprayed May 1, and still 
less on those sprayed June 1. In fact, the latter appeared at that 
time to be an almost perfectly successful treatment and the plat was 
scarcely inferior to those which received two or even four treatments. 
By October 12 the controls and also the plat sprayed early were com¬ 
pletely defoliated. All the trees were beginning to shed normally a 
little, so that slight differences had developed which were not apparent 
on the first visit. The conclusions from a study of these results areas 
follows: 
(1) The earliest treatments gave the poorest results, and of the sin¬ 
gle treatments there Avas an increase in effect up to June 1. Between 
May 15 and June 1 there was but slight difference. 
(2) Two sprayings (on May 1 and 15 or on May 1 and June 1) left so 
little to be desired that they may be considered sufficient treatment for 
an orchard. The improvement from the additional third and fourth 
treatments was very slight and was visible only at the close of the 
season. 
(3) Pear leaf-blight on orchard trees in this section of Virginia does 
not commence its work early in the season, but is a late-appearing 
fungus. It develops on the foliage after the leaves are quite mature 
and continues to multiply after August 1. The attacks of fungi which 
caused differences to appear between plats 2 to 8 came mostly after 
August 2, long after the spraying was done, thus indicating that it was 
the thoroughness with which the trees were covered or the amount of 
fungicide on them that was important rather than the time when it was 
applied. 
(4) From the results it would seem that the first spraying should be 
postponed until late in the spring, in order to have the fungicide fresh on 
the leaves during the first attacks of' the disease, but should be made 
early enough to get ahead of the fungus. The second treatment should 
be made just ahead of the principal attack of the fungus and late 
enough so as to last well through the season. A leaf thoroughly 
sprayed once as late as June seemed to be protected for the rest of the 
season. The disadvantage of the early treatment is apparently due to 
the long exposure of the fungicide to the weather before the critical 
time. 
