14 GRAPE-SPRAYING EXPERIMENTS IN MICHIGAN IN 1SJ09. 



Second application, jtist before blossoming or as near blossoming 

 time as possible, using the same fungicide. This is to cover the 

 leaves which have recently come out, as Avell as the clusters of young 

 blossom buds. 



Third application, just as the blossoms fall, when the fruit is 

 setting. This, when properly done, covers the young fruit and pro- 

 tects it from the disease. 



The fourth application should be from one to two weeks after the 

 third, depending on the weather. If it is hot, with frequent rains, 

 the spraying should not be delayed more than one week, while if there 

 is very little rain the interval might be lengthened to ten days or two 

 Aveeks. 



The fifth application should be about ten days after the fourth, 

 using 4—3-50 Bordeaux mixture, as in all previous sprayings, with 

 the addition of 2 pounds of resin-fishoil soap. The soap should, 

 however, not be used after July 15. 



Fixed nozzles may be used in the first three sprayings, but it is 

 much better to use trailers or long hose with nozzles directed by hand 

 in the last two. The foliage is heavy by the time for the fourth appli- 

 cation and it is impossible to cover the young grapes properly with 

 fixed nozzles. In the case of a vinevard which has been thoroughlv 

 sprayed for some seasons and where there js but a small amount of 

 rot present, it would probably be unnecessary to spray more than 

 three times in a dry season. These applications should correspond 

 to the first three given in the foregoing outline. When it is deemed 

 necessary to spray after July 15, a nonstaining compound should be 

 used. For this purpose neutral copper acetate, 1 pound to 50 gallons, 

 is the best mixture tested in these experiments. 



In making Bordeaux mixture, good stone lime should be used 

 whenever possible and the mixture should be prepared as described 

 in Farmers' Bulletin 284. Thoroughness in application can hardly 

 be too strongly emphasized. The mixture should be applied at the 

 rate of 125 gallons to the acre and under a pressure of 100 to 125 

 pounds. Some good nozzle that will make a fine mist-like spray 

 should be used. All portions of the vine should be covered. After 

 the fruit sets it should receive sjjecial attention, and an effort should 

 be made to cover the berries as thoroughly as possible. Much of the 

 indifferent success in spraying is due to carelessness in the mixing 

 and lack of thoroughness in the application. 



SUMMARY. 



The work in lUOlJ has shown that black-rot can be controlled by 

 proper methods of spraying and cultivation even in a season particu- 

 larly favorable for the development of the disease and in a vineyard 



[Cir. 65] 



