158 MAINE AGRICULTURAL EXPERIMENT STATION. I916. 



In 191 5, two applications of the combination spray were made 

 as in the previous year. The orchard was plowed once during 

 June and received no further cultivation during the entire 

 season. The drops were allowed to remain on the ground, and 

 an examination of this orchard in April, 1914, showed numer- 

 ous rotted apples below the trees. 



A general infestation of the apple maggot had occurred 

 throughout this orchard during 19 13, and all of the different 

 varieties of apples had been attacked by the pest. The most 

 seriously infested variety, however, was the Tolman Sweet. 



None of the other orchards had been sprayed for the control 

 of insect pests and fungous diseases. The owners stated that 

 they had been troubled for a number of years with the railroad 

 worm and that the drops had been allowed to decay on the 

 grass in previous years. 



Poisoned bait formula. In 191 5, the following formula of 

 the poisoned bait was used in spraying the six orchards and the 

 apple trees in the residential section : 



Potassium arsenate 3-4 oz. (dissolved in boiling water) 



Molasses 1 pt. 



Water 3 gal. 



The solution was prepared by stirring the molasses in three 

 gallons of water until all of the molasses on the bottom of the 

 pail was dissolved. The potassium arsenate was first dissolved 

 in .about a quart of boiling water and was then added to the 

 diluted molasses. The poisoned bait was thoroughly agitated 

 by pumping the liquid back upon itself with a spray pump. 



Application of Poisoned Bait. The poisoned bait was applied 

 with a common, garden, brass spray-pump provided with a rose 

 sprinkler nozzle, which throws a mist-like spray. A different 

 method was employed in applying the insecticide in each sea- 

 son. In 1914, the man applying the spray walked rapidly 

 around the tree, a yard or more away from the ends of the 

 lower outermost branches, and at the same time the poisoned 

 liquid was forced from the pump, into the air toward the top 

 of the tree. The minute drops fell over and into the tree 

 resulting in an even distribution of the droplets, for the mo.-t 

 part on the upper surface of the leaves. The dose per tree 

 varied from a half pint to a quart depending upon the size of 



