REPORT OP COMMITTEE ON PUBLICATION 225 



sulphate, three pounds lime, and two pounds of dissolved soft soap, to each 

 50 gallons of water. The lime-sulphur combinations almost completely de- 

 foliated the grapes and should not be used as a summer spray for grapes. 



In treatments, the grapes were machine-sprayed with a traction sprayer 

 by going through between the rows once, and spraying each row, one on each 

 side; by going through the rows twice, giving them a double machine applica- 

 tion; by spraying heavily using special spars on a power sprayer, and by 

 spraying the grapes by hand with nozzles directed by the experimenter. 

 Hand work gave the best results by a small per cent, but double machine 

 work was much more rapid and one machine could cover three to five acres 

 per day, going over each row twice. The power sprayer covered the grapes 

 with spray, only one application being necessary, using 135 to 180 gallons per 

 acre. Per cents are as follows for the season of 1907: 



Wormy 



Unsprayed with poison 58.37 per cent 



Hand Sprayed once in late July 2.90 per cent 



Single Machine Sprayed twice June and late 



July 20.44 per cent 



Sprayed three times, double machine 4.47 per cent 



Sprayed three times by hand 3.00 per cent 



These results were for the season of 1907 and show the percentages of 

 wormy grapes. The treatment in July, spraying once with arsenate of lead, 

 shows a very small per cent of wormy grapes, but the yield was smaller than 

 on the other plots. The unsprayed plot yielded at the rate of 1469 pounds 

 per acre, while the hand .sprayed and double-machine sprayed plots yielded 

 at the rate of over 6,000 pounds per acre. 



In 1908, arsenate of lead only was used as a poison, and bordeaux with 

 soap and iron sulphate as stickers for the poison. The results were as 

 follows. 



Wormy 



Unsprayed, no poison 47.43 % 



Sprayed with arseuate of lead (spraying once before bloom) 20.88 % 



Sprayed with arsenate of lead, bordeaux and iron sulphate, 3 



sprayings, double machined 1.95 % 



Arsenate of lead, bordeaux and soap, 3 sprayings, double ma- 

 chined 4.67 % 



Arsenate of lead, bordeaux and soap, 3 sprayings, hand sprayed .71 % 

 These results are based on a certain number of pounds of grapes picked 

 at random from each plot and the wormy and sound berries counted in each 

 case. 



The average results for two years' work are as follows: 



Wormy 



Unsprayed with poison 52.90 % 



Double machine, three sprayings 4.57 % 



Hand sprayed, three sprayings 1.85 % 



In this average, soap was used as a sticker (during the last two years of 

 the experiments) in connection with the arsenate of lead and bordeaux. In 

 1910, arsenate of lead and bordeaux with soap was tried, in comparison with 

 commercial lime-sulphur, one in fifty, and three pounds of arsenate of lead 

 added to the diluted lime-sulphur. The commercial lime-sulphur injured the 



