158 Report of State Board of Horticulture. 



scale. Treated with water but once, and that on March 4, the day suc- 

 ceeding the application of the insecticide spray. Rainfall of course fol- 

 lowed on the seventh, eleventh, and fifteenth, as on all other trees of this 

 experiment, amounting to about fifteen gallons of water additional. Thir- 

 ty-seven per cent of the scales alive at the time of treatment; seventy- 

 eight per cent of these dead three days after, and eighty-six per cent 

 dead on the twelfth day. The final general effect was the killing of 

 ninety per cent of the scales. 



Tree No. 3. — An eighteen-foot tree, with an eight-inch trunk and a thir- 

 teen-foot top; in good general condition, but badly infested. Water treat- 

 ment three days after the insecticide application, and twice on alternate 

 days thereafter, making forty-five gallons of water thus applied. Twenty- 

 nine per cent of the scales alive when the treatment began; fifty-three 

 per cent of these dead on the third day, and seventy-nine per cent on the 

 seventh; the average final destruction of scales, seventy-eight per cent. 



Tree No. 5.^A fifteen-foot tree, with an eight-inch trunk and an eleven- 

 foot top; in poor condition, badly infested. Sprayed with fifteen gallons 

 of water five days after treatment, and again two days later. Forty- 

 seven per cent of the scales alive in the beginning; eighty per cent of 

 these killed by the sixth day, when the first count was made, and ninety 

 per cent by the twelfth; average final effect of the treatment, the de- 

 struction of ninety-two per cent of the scales. 



Tree No. 6. — A fifteen-foot tree, with an eight-inch trunk and a twelve- 

 foot top; in poor condition, moderately infested by the San Jose scale. 

 Treated but once with water, and this on the seventh day after the insec- 

 ticide spray, when thirty gallons were applied. Sixty-four per cent of 

 the scales alive in the beginning; eighty-four per cent of these dead by 

 the sixth day and eighty-six per cent by the twelfth; average ratio of 

 scales finally killed, eighty-six per cent. 



Tree No. 7. — An eighteen-foot tree with an eight-inch trunk and a ten- 

 foot top; in poor general condition, moderately infested by the scale. 

 Fifteen gallons of water on the thirteenth day after insecticide treatment, 

 and another fifteen gallons on the fourteenth; before this, only the rain- 

 falls already described. This tree and all the remaining trees of this lot 

 were practically check trees with regard to the effects of the water sprays, 

 since these were applied after the full effect of the insecticide must have 

 been produced. Sixty-eight per cent of the scales alive in the beginning; 

 eighty per cent of these dead on the fifth day and eighty-three per cent 

 on the seventh; ratio finally killed, eighty-eight per cent. 



Tree No. 8. — Seventeen feet high, with an eight-inch trunk and a twelve- 

 foot top; in fair general condition, but badly infested with the scale. 

 But one application of water, and that fifteen gallons on the fourteenth 

 day after insecticide treatment. Fifty-four per cent of scales alive in the 

 beginning, and fifty-four per cent of these dead on the third day; ninety 

 per cent dead on the sample representing the fifteenth day, with an 

 average of eighty-eight per cent destroyed as the final effect of the in- 

 secticide. 



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