Department of Horticulture. 533 



conditions unpleasant for them, and they seek more congenial places. 

 As yet Bordeaux mixture is the most effective remedy known against flea 

 beetles. 



In this survey slightly more than li per cent, of the farmers who 

 grew potatoes stated that they sprayed with Bordeaux. These men pro- 

 duced almost 18 per cent, of the potatoes, showing that those who sprayed 

 were larger producers than the average grower. Their average produc- 

 tion was over 120 bushels last year, while the average of the Long Island 

 survey was but 115 bushels per acre. Though this gain is small, yet 

 it was obtained in a year when because of the dry season potato rot 

 was not severe and spraying had but small effect. In the extensive and 

 careful experiments of the Geneva Station in this territory, it was shown 

 that the use of Bordeaux has for the past seven years given an- average 

 gain of 29 1-3 bushels per acre for three applications, and of 54 bushels 

 when used every two weeks. Since Bordeaux spraying is practiced to 

 so small an extent, and since it appears to give a substantial gain in pro- 

 duction every year, we are convinced that for many growers spraying 

 would pay, and we urge its more extensive practice. 



Dipping for aphis or plant lice. Forty-three farmers reported aphis 

 to have been severe on cabbage, cauliflower, and Brussels sprouts. When 

 the aphis appears on the plants early in the season, while they are in 

 the seed-bed, it will be found effective to dip the plants in a solution 

 of whale-oil soap. To make the solution, dissolve the soap in hot water 

 at the rate of one pound to 20 gallons of water. When the plants are 

 taken up from the seed-bed to be transplanted to the field they may be 

 dipped by bunches, so that all the tops are submerged. Care should be 

 taken, however, not to immerse the roots, nor to set the plants out while 

 still wet if the day is hot and bright. 



The plants may also be effectively sprayed for the aphis with either 

 the whale-oil soap solution or kerosene emulsion. To do this successfully 

 the rows of plants must be sprayed carefully both on the upper and the 

 under side of the leaves. This cannot be done with the ordinary fixed- 

 nozzle type of sprayer, such as is driven down the rows of potatoes. A 

 type of sprayer is required with a nozzle on the end of a short curved 

 extension rod directed by hand so that the under side of the leaves can 

 be reached. The whale-oil soap solution is made by dissolving one pound 

 of soap in five or six gallons of water. For the making of kerosene 

 emulsion see Cornell Bulletin 252 on Insect Pests and Plant Diseases. 



Formalin treatment for scab. Where the scab fungus attacks the 

 potato crop the seed potatoes should be treated with formalin before 

 being planted in the soil. The fungus usually gets into the land through 



