REPORT OF THE SOCIETY 37 



Nicotine Dusting. 



During the past six years, great changes have been made in nicotine 

 dusting. The first nicotine dust made by Prof. Smith of Cahfornia was 

 nicotine sulphate sopped up in dried china clay. The nicotine in this material 

 was almost completely non-volatile and, in view of our present knowledge, 

 it is a wonder that dusting with nicotine ever got by the initial stages. Luckily 

 it was used first on the walnut aphis, which is very easy to kill and the thick 

 foliage of the walnut tree held what vapors were liberated until they had done 

 their work. On almost any other insect or on any other type of tree the original 

 nicotine dust would have been branded a failure. There is a lesson here that 

 should prevent us from forming too hasty judgments on new materials. 

 Later, some one found that the addition of a small quantity of lime made nicotine 

 dust more effective. Then some one found that it was the volatile nicotine 

 that did the killing, that nicotine dusting was gassing or fumigating and that 

 it was not necessary to actually hit the insect with the dust in order to make 

 a kill. 



During the winter and spring of 1921-22, Dr. Headle of New Jersey 

 began a series of experiments on the rapid volatilization of nicotine from dust. 

 The Headle dust formulas have increased the value of nicotine dusting mat- 

 erials by from five to twenty times, depending on the honesty and intelligence 

 of the various commercial concerns applying them. Let me illustrate. 



On the whole, dusting has made remarkable progress during the past 

 season, for the most part on its own merits. The highest yielding potato 

 field on Long Island was a dusted field. Potato dusting on Long Island and 

 in Maine w^as fully as satisfactory as spraying, while in Florida it surpassed 

 spraying on account of the extra stimulation resulting from the dust. Where 

 at the beginning of last season one dusting machine was working on citrus 

 in Florida, by the end of last season one concern had sold 109 power dusting 

 machines in Florida for citrus work. This year the same concern is placing 

 over 100 power dusting machines in one county in Florida. 



In Nova Scotia they bought 200 more dusting machines last season, 

 dusted 80 per cent of the crop and grew the cleanest crop as well as one of the 

 largest crops since 1911. Since Nova Scotia took to dusting in a large way 

 in 1919, they have grown four large, continuous crops that have averaged more 

 than double the average of the previous seven crops when they were spraying 

 with lime sulphur. 



At the meeting of the New York State Horticultural Society two months 

 ago, the evidence of the growers was all in favor of dusting, the largest growers 

 in New York State, Collymer Bros., stating that if they had dusted their entire 



