The Black-rot of the Grape, and its Control. 



221 



Fifth, July 23-24. 



Sixth, Aug. 5-6 (Ammoniacal copper carbonate on all plats except 

 check and No. 2). 



Seventh, Aug. 20-21 (Aminoniacal copper carbonate same as above). 



Cultivation. — Plats 3, 4, 5, 6, 7, 8, 9 were plowed in the spring. The 

 soil was thrown from the rows. The grape hoe was tised to cultivate 

 between the vines, and following this for clean work, the hand hoe. The 

 furrows were then cut with a cutaway harrow. The spring-tooth harrow 

 followed this, leaving the ground level and mellow. Cultivation was 



Fig. 185 — Vineyard sprayer tised in the experiment, showing stationary nozzles at 



side: also trailers with extension rod. 



continued on these plats until about the middle of July when cover- 

 crops were sown as follows: 



Rows 24-28 crimson clover Ji^ty 16 



" 29-33, vetch " 16 



" 3 5~39) criinson clover " 16 



" 40-44, vetch " 16 



" 46-50, mammoth clover " 24 



" 57—61, crimson clover " 24 



" 90-99, buckwheat " 24 



The latter part of the summer was dry, and the cover-crops did not 

 grow well. Vetch and buckwheat did the best, with crimson clover 

 third. 



The appearance of the rot. 



On the night of Thursday, July 10, the rot was first discovered on 

 the leaves. It was almost entirely on the suckers at the base of the vines, 



