56 MAINE AGRICULTURAL EXPERIMENT STATION. I9OO. 



■due to an actual growth of dry matter, rather than to a drying 

 out of the water with a diminished weight of crop. The 

 increase was largely from the growth of starch, sugar and allied 

 bodies. 



SPRAYING. 



Spraying with fungicides and insecticides has received con- 

 siderable attention. Among the questions studied are the fol- 

 lowing : The effectiveness of the treatment in producing perfect 

 fruit ; the relative number of windfalls on sprayed and unsprayed 

 trees ; the preparation of spraying mixtures ; the best time for 

 spraying. Results: All trees sprayed with arsenical poisons 

 had a smaller percentage of wormy fruit than did the unsprayed. 

 Paris green was found less injurious to the foliage than was 

 London purple or white arsenic. A mixture of 1 pound Paris 

 green in 250 gallons of water was effective in reducing the 

 amount of wormy fruit, but a stronger mixture (1 pound to 

 100 gallons) was required to kill the tent caterpillar. The 

 number of windfalls was greatly lessened by spraying with 

 Paris green and the proportion of wormy fruit among the wind- 

 falls was also smaller from the sprayed trees. 



It was observed that most often wormy fruits from sprayed 

 trees are entered from the side or base, while in fruits from 

 unsprayed trees the entrance at the calyx were largely in excess. 

 Spraying trees three times with an ammoniacal solution of copper 

 carbonate destroyed the apple scab fungus and resulted in sav- 

 ing 52 per cent of the crop. The most effective fungicide used 

 was Bordeaux mixture and this is now generally used through- 

 out the State. 



INJURIOUS INSECTS. 



The department of entomology and botany was established in 

 the Station in 1898. The work of investigation has consisted 

 of studies in the field and laboratory of the life histories of 

 insects and plants of economic importance. This has resulted in 

 an increased knowledge of old enemies and means of combat- 

 ing them and in the working out of the complete life history 

 of Trypeta pomonella (apple maggot) and Epochra canadensis 

 (currant fly), and the discovery of numerous facts regarding 

 the habits of many other insects of economic or entomological 



