72 N. H. AGR. EXPERIMENT STATION [Bulletin 143 



and Deerfield, in many of which the work was repeated the sec- 

 ond year. Altogether over a million apples, ou 521 trees, 

 from 102 different plots were recorded. Every apple, which 

 dropped after mid-Julj' or which was picked was examined and 

 recorded. Its condition as to worminess, whether the worms had 

 entered the calyx or side of the apple, and whether it was injured 

 by worms of the first or second brood was recorded. All the trees 

 used in the experiments were Baldwins. ]\Iost of the plots were 

 arranged so that blocks of at least fifteen trees were given similar 

 treatment, and only the five central trees in the block were 

 recorded, discarding the outside trees which might be affected 

 by the neighboring plots. Therefore the total number of trees 

 sprayed was nearly 1,500, though only 521 were recorded. 



The detailed report of these experiments has been published 

 and may be had upon application, but is of but little interest 

 to the general reader. The conclusions drawn from the experi- 

 ments are as follows : 



1. Value of Different Insecticides. Arsenate of lead and 

 Paris green are practically the only arsenical insecticides in gen- 

 eral use against the codling moth. Where they are used alone 

 the arsenate of lead is much superior to Paris green on account 

 of its superior adhesiveness, not being washed off by rains as is 

 Paris green, and because normal arsenate of lead never burns the 

 foliage, as Paris green sometimes does. Where they are used 

 with Bordeaux mixture, there is but little choice, as the Bordeaux 

 sticks the Paris green to the foliage so that it adheres fully as 

 well as arsenate of lead, though an occasional slight burning of 

 the foliage results from Paris green. 



2. Amount of Insecticide. Two pounds of arsenate of lead 

 to 50 gallons of water gave very satisfactory results and was 

 much superior to one pound. Where the work i.s thoroughly 

 done two pounds per barrel are sutficient, but we believe three 

 pounds per barrel, as usually recommended by the manufac- 

 turers, will be found profitable where spraying is done with a 

 barrel pump with only average care. One-third of a pound of 

 Paris green per barrel was found ,to be as effective, as far as 

 killing the codling moth is concerned, as two pounds of arsenate 

 of load, where both were applied with Bordeaux mixture. Two- 



