New Yoek Agricultural Experiment Station. 221 



In each spraying the bordeaux was applied uniformly and very 

 thoroughly with a knapsack sprayer, the quantity varying from 

 about 100 gallons in the first spraying to about 250 gallons per 

 acre in the later ones. The bordeaux used contained six pounds 

 of copper .sulphate in each 50 gallons and lime somewhat in 

 excess of the quantity required to satisfy the potassium fer- 

 rocyanide test. N^o attempt was made to spray the undersurface 

 of the leaves. 



Until nearly the middle of September the unsprayed rows ap- 

 peared to be in as good condition as the sprayed ones. On Sep- 

 tember 15 a contrast was observed for the first time. The foliage 

 of the rows sprayed eveiy two weeks was perfect while that of the 

 unsprayed rows began to show tip bum. Although it was not 

 marked there was certainly a difference. From this time until 

 about October 15, when the unsprayed rows were entirely dead, 

 the contrast between sprayed and unsprayed rows became grad- 

 ually more and more pronounced. The condition of the rows 

 sprayed three times was intermediate between that of unsprayed 

 rows and rows sprayed every two weeks. On all rows, the plants 

 in the north half of the field died somewhat earlier than in the 

 south half. Viewed from the south end on October 23 the rows 

 sprayed seven times appeared to be in nearly full foliage ; while 

 rows sprayed three times showed only an occasional green branch ; 

 and the check rows were entirely dead. The first killing frost 

 came on the night of October 27, at which time the rows sprayed 

 seven times were still quite green over the south half of their 

 length though nearly dead over the north half. 



There was no late blight whatever, only a very little early 

 blight and a very little flea beetle injury. The unsprayed rows 

 were affected by no disease of any consequence except tip bum 

 and even of that there was only a moderate amount. As the plants 

 were still partially alive twenty weeks after planting it is clear 

 that they could not have been very much injured by anything. Yet 

 spraying increased the yield at the rate of 93 bu. per acre. Plainly, 

 we have here a striking example of the beneficial influence of 

 bordeaux in the absence of diseases and insect enemies. Of course, 



