162 Report of State Board of Horticulture. 



Taking this group of nine trees as a wtiole and averaging all statements 

 concerning them, it appears that forty-two per cent of the scales were 

 alive when the experiment began; that fifty-six per cent of these had been 

 killed by the treatment by the second day thereafter, seventy-one per cent 

 by the fourth and eighty-four per cent by the fifth; and that the final 

 average effect was approximately eighty-nine per cent destroyed. 



To this lot it will be convenient to add for discussion two other trees 

 sprayed with lime, sulphur, and salt on the seventh of March, which, it will 

 be remembered, was the day of the first rainfall occurring in the experi- 

 mental period. These trees received no water treatment, but were in- 

 tended as checks on the other experiments. 



Tree No. 38. — The first of these was a peach tree, nine feet high, with 

 a five-inch trunk and a ten-foot top. It was in excellent condition, and 

 only moderately infested. Thirty-eight per cent of the scales were alive 

 on the day preceding the insecticide application, and on the day following 

 the treatment thirty-one per cent of these were dead. No other count 

 was made upon this tree until the eleventh Aaj, when ninety-six per 

 cent appeared to have been killed. The final general effect was an 

 average of eighty-nine per cent of the scales destroyed. 



Tree No. 39. — The second tree of this pair was also a peach tree, about 

 nine feet high, with a five-inch trunk and a ten-foot top. It was in ex- 

 cellent general condition, and moderately infested. Only twenty-seven 

 per cent of the scales were alive when the experiment began; twenty-nine 

 per cent of these were dead by the second day after treatment, and eighty- 

 four per cent by the third day; and the general final effect averaged ninety- 

 one per cent of the scales destroyed. 



GENERAL RESULTS OF EXPERIMENTS WITH LIME, StTLPHUE, AND SALT. 



An analysis of the data contained in the above descriptions of Lots 1 

 and 2 and in the tables of percentages for those lots enables us to dis- 

 tinguish two gi'oups of trees; those which received some treatment of 

 water within five days after the insecticide application, and those which, 

 if treated with water at all, did not receive it until the principal effect of 

 the insecticide had already been produced. There are eleven trees in the 

 first group, namely, 1, 2, 3, 4, 5, 27, 29, 31, 32, 33, and 36, and nine trees 

 in the second, namely, 6, 7, 8, 9, 10, 20, 35, 38, and 39. 



The average final effect of the insecticide upon the nine trees of the 

 second group was the destruction of ninety and six-tenths per cent of the 

 scales, and the corresponding destruction on the eleven trees of the first 

 group was eighty-six and one-tenth per cent, making a difference of four 

 and five-tenth per cent due to the action of water on the insecticide when 

 applied within five days after the original treatment. In other words and 

 more generally stated, it may be said that in these experiments the effect 

 of thoroughly watering the treated tree during the first five days after 

 the experiment began, was to diminish the destructive effect of the 

 insecticide by approximately five per cent. 



