24 CONTROL OF PEACH BROWN-ROT AND SCAB. 



of peach scab. They sprayed their orchard of 600 acres in 1908 and 

 again in 1909 and report that they obtained good results both sea- 

 sons. In previous years the scab had been so bad that a large 

 percentage of the crop was lost each year, and the owners con- 

 sidered the orchard unprofitable until the lime-sulphur treatment 

 made possible the control of this disease without injury to the 

 foliage. 



During 1908 the Sleepy Creek Orchard Company, of Sleepy Creek, 

 W. Va., sprayed their orchard of 15,000 peach trees from three to six 

 weeks after the petals fell with 8-8-50 self-boiled lime-sulphur. A 

 portion of the orchard was sprayed again a month later. Fortunately 

 in this orchard trees were left unsprayed as checks and the difference 

 between the sprayed and unsprayed fruit was so striking that the 

 writers deemed it worth while to sort the fruit from several trees and 

 obtain exact percentages of scab infections. From an Elberta 

 tree sprayed twice there were 1,551 peaches, 15 per cent of which 

 was slightly affected with scab and none badly scabbed. Another 

 Elberta tree sprayed only once had 731 peaches, 44 per cent of which 

 showed some scab spots, but only 1.3 per cent was badly scabbed. 

 (See PI. IV, fig. 1.) An unsprayed tree in the check block had 468 

 peaches, all of which were affected and 86 per cent badly scabbed. 

 (See PI. Ill, fig. 2, and PI. IV, fig. 2.) These three trees selected 

 for this count work were situated close together in a rather low place 

 where the scab would naturally be bad. It will be observed that one 

 spra3'ing held the disease in check, so that only a little more than 1 

 per cent of the crop was badly affected, while 86 per cent of the un- 

 sprayed fruit came in this class. However, it would not be wise to 

 conclude from this that one application is sufficient. It is shown that 

 44 per cent of the fruit sprayed once had some scab infections. The 

 second application reduced this to 15 per cent, none of which was bad. 

 In other words, all of the fruit from the trees sprayed twice was 

 suitable for packing, and none of it had enough scab to attract atten- 

 tion; all but 1 per cent of the fruit from the trees sprayed once was 

 suitable for packing, but had enough scab infections to detract 

 somewhat from its appearance, while 86 per cent of the fruit from 

 the unsprayed trees was entirely unsuited for the market and the 

 remainder was sufficiently affected to decrease its market value. 



COURSE OF TREATMENT RECOMMENDED. 



Self-boiled lime-sulphur, when properly applied, will entirely con- 

 trol peach scab, and when the curculio does not interfere too seri- 

 ously it will largely prevent brown-rot. In view of the fact that 

 numerous brown-rot infections take place through curculio punctures, 

 it would seem advisable, where the two troubles occur together, to 

 use arsenate of lead in connection with the lime-sulphur mixture as a 



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