4 BULLETIN 368^ U. S. DEPARTMENT OF AGRICULTUEE. 



A comparison of the time of the development of the apothecia with 

 the dates of infection on the prunes furnishes strong evidence that 

 the apothecia were the source of infection. Further evidence of this 

 may be found in the fact that Monilia could not be found in fruiting 

 condition on cankered limbs, although a very careful search was 

 made. The fact that the disease was much worse on the lower limbs 

 than in the tops of the trees might be taken as further evidence that 

 the infection was from below, but moisture conditions may have been 

 of importance in producing this difference. It was also fomid that in 

 orchards where early spring plowing and cultivation were practiced 

 there was little or no calyx infection of brown-rot. While soil varia- 

 tions and the effects of culture upon the general vigor of the tree must 

 not be lost sight of, there is little doubt that the deterrent effect of the 

 cultivation upon the development of the apothecia was of direct value 

 in the prevention of the disease. 



The wind is probably the important agent in spreading the spores 

 of the fungus. Insects may be concerned to some extent in this dis- 

 tribution, but are of greater importance on account of the punctures 

 they produce on the fruit, these injuries furnishing an entrance point 

 for the fungus. Among the insects, the fruit-tree leaf syneta (Syneia 

 albida Leconte) is probably of importance, as it was present in great 

 numbers during the early part of the season, feeding on both fruit 

 and foliage and causing much damage. 



SPRAYING EXPERIMENTS. 



Further evidence of the importance of the blossom infection was 

 obtained from the sprayiijg experiments of the season of 1915. The 

 work was carried on in the orchards of A. W. Moody, at Fehda, 

 Wash. The first spraying was made on March 17, when the buds 

 were beginning to swell, a second on March 24, when the cluster buds 

 were open and the blossoms showing white, and a third on April 8, 

 when the petals were practically all off. The first a,pphcation was 

 made with 4-4-50 Bordeaux mixture; the later ones with 8-8-50 

 seK-boiled lime-sulphur. No spreader or sticker was added in 

 any of these applications. At the time of the third spraying but 

 httle evidence of the second could be fomid on the trees. The two 

 weeks of almost constant rain had apparently washed most of it off. 

 It was evident that something should have been added to the fungi- 

 cides to increase their adhesive qualities. It was also evident from 

 the time the infections appeared that better results would have been 

 secured if the second and third applications had been nearer together. 



The heavy infection described, which had taken place previous to 

 the third spraying, made it plain that it was then too late to secure 

 the best results. Notes taken May 10 to 15, however, showed that 

 the spraying had saved a considerable percentage of the crop. At that 



