REPORT OF THE STATE ENTOMOLOGIST I9II 1 5 



codling- moth. The conditions we consider typical of a well- 

 kept commercial orchard. Plots i, 2 and 3 were located in the 

 northern end of the orchard on a gently sloping side hill, the 

 actual experimental trees being separated from adjacent wood- 

 land by at least three barrier trees. The conditions were fairly 

 uniform, the plots producing respectively 16,638, 19,994 and 

 20,926 apples. It will thus be seen that the largest yield was 

 on plots 2 and 3 and, as a consequence, the test for the single 

 spraying was fully as severe as in the case of the trees receiving 

 two and three applications. Plot 4 and the check trees were 

 located near the southern end of the orchard and bore relatively 

 less fruit. 



The trees were sprayed for the first time May i8th. The 

 day opened with rain about 7 o'clock, continuing to nearly 9, 

 and then breaking with showers till about ii o'clock, sprinkling 

 again at 1.45 and with a few showers till about 4.20 p. m., at 

 which time it poured. Spraying began at about 1.25 p. m. on 

 plot 2 at which time there was a slight breeze. The treatment 

 of the actual experimental trees was completed by 1.35 and then 

 working southward those of plot i were finished by 1.46. A 

 sprinkling of rain began at 1.45 and was rather lively at 1.46, 

 stopping at 2 p. m. The leaves at this time were partly flooded 

 with rain but there was no marked dripping. An examination 

 of the experimental trees in plots 2 and i showed that in the 

 former, sprayed some ten minutes before the rain began to fall, 

 there was very little or no washing, while in plot i those trees 

 which had been completed just a few minutes before the rain 

 came, showed some washing though this was limited largely 

 to the carrying of the poison to the lower edge of the leaf where 

 it settled in large drops. There was very little dripping and 

 probably nothing was washed from the blossom ends of the 

 young fruit. Spraying on the barrier trees was started at 2.10 

 p.m., at which time the trees were wet but not dripping. The 

 experimental trees on plot 3 were sprayed at 3.15 p.m., the 

 foliage being dry. The work in this entire plot was completed 

 about 3.45, though some of the barrier trees on plot 2 were not 

 finished till nearly 4 p.m., at which time there was a sprinkling 

 of rain, it pouring by 4.20. Only 150 gallons were necessary 

 to cover most of four rows in plots i and 2, or 59 trees. 



The spray applied consisted of 7^ pounds of Grasselli's 

 arsenate of lead (15 per cent arsenic oxid) and 4I/2 gallons of 



