SPRAYING AGAINST GRAPE LEAFHOPPER. \) 



This shows an average increase in weight of 1.7 pounds per basket 

 for fruit from the sprayed vines. As in the case of all the other exper- 

 iments, the foliage on the sprayed vines remained green and healthy 

 throughout the season, and new growth of canes continued to be made 

 for a longer period than upon the unsprayed vines. 



USE OF COMBINED CONTACT AND POISON SPRAY. 



In addition to the experiments described, in which the spray ingre- 

 dients consisted of either tobacco extract No. I and water or tobacco 

 extract No. II and water, other experiments were made, in one case 

 adding the tobacco extract No. II to Bordeaux mixture and fish-oil 

 soap. In this experiment about two-thirds of an acre of the infested 

 vines was sprayed with the Bordeaux, fish-oil soap, and tobacco 

 extract No. II mixture, and about one-third of an acre was sprayed 

 with tobacco extract No. II and water. So far as could be observed 

 the killing effect of tobacco extract No. II upon the nymphs when 

 mixed with the Bordeaux and soap was in no way lessened; nor 

 was any injurious effect apparent to the leaves and fruit of the vines 

 sprayed with this mixture. The ingredients were used in this mixture 

 at the following dilution: Bordeaux mixture, 3 pounds lime, 3 

 pounds copper sulphate to 50 gallons of water, plus 2 pounds of fish- 

 oil soap, and tobacco extract No. II at a dilution of 1 to 1,500 partsof 

 the Bordeaux mixture. Tobacco extract No. II at a dilution of 1 to 

 1,500 parts water. 



In another experiment 5 acres of vineyards were sprayed with a 

 mixture of Bordeaux, arsenate of lead, and tobacco extract No. I, at 

 the following dilution, 3 pounds of lime, 3 pounds of copper sulphate, 

 2 pounds arsenate of lead to 50 gallons of water plus tobacco extract 

 No. I, 1 to 150 parts of the Bordeaux mixture. So far as could be 

 observed the killing effect of the tobacco extract upon the nymphs 

 was not lessened in this mixture nor were any injurious effects from 

 this mixture observed upon the foliage and fruit of the vines. The 

 object of adding the tobacco ingredient to the Bordeaux and the 

 arsenate of lead mixtures is an endeavor to reduce the number of 

 applications made necessary in some instances to control the several 

 insect and fungous enemies attacking the foliage or the fruit of the 

 grapevine. The advisability of applying the tobacco extracts against 

 the grape leafhopper with Bordeaux and arsenate of lead will be a 

 matter for the individual vineyardist to decide after he has made a 

 thorough examination of his vineyard to determine if other insects 

 are present in numbers sufficient to warrant their treatment. The 

 insects which may possibly be infesting the foliage or fruit of the grape 

 at the time of treating the nymphs of the grape leafhopper with the 

 tobacco extracts are the grape rootworm and the grape berry moth. 



The second poison application against the grape rootworm to the 

 surface of the leaves of the grape is usually made during the first two 



