64 MAINE AGRICULTURAL EXPERIMENT STATION. I91I. 



estimated at 50 per cent, but none of it was of a degree severe 

 enough to materially affect the functions of the tree. 



In the other divisions control, so far as careful observations 

 showed, was excellent and practically equal. The foliage was 

 not entirely free from the fungus, but the infections did not be- 

 come sufficiently established to do any evident damage. Such 

 scabby foliage averaged from 4 to 8 per cent on the different 

 plots. 



In estimating the efficiency of control on the fruit, scab alone 

 was considered. No gradations of scabby fruit were made; 

 the resulting data therefore do not show the amount of fruit 

 which was very slightly affected. This in practically all cases 

 was more than 50 per cent of the scabby fruit of all sprayed 

 plots, and should be taken into consideration. 



Effectiveness of Lead Arsenate. 



The results obtained indicate an almost perfect control of 

 insects affected by arsenicals. The unsprayed plots were thor- 

 oughly infested during the season by codling moth {Carpocapsa 

 pomonella, L.), yellow-necked caterpillar (Datana ministra), 

 tussock moth (Hemerocampa leiicostigma) and fall web worm 

 (Hyphantria cunea). The last was extremely prevalent in 

 jNlaine this season, and the check rows and unsprayed trees in 

 the neighborhood were covered with the caterpillars. Not only 

 leaves but fruit as well were attacked by them in Plot i. . 



On the other hand, practically no trace of any of the afore- 

 mentioned pests could be found on any of the sprayed plots. 

 The cigar-case bearer {Coleophora fletcherella) and bud moth 

 {Tmetocera oceUana) were present in all the orchards in the 

 spring; the first spraying was not early enough to check the 

 work of either insect, and some injury was done by the latter. 



It should be noted that almost every fruit classed as wormy 

 was in the case of the sprayed plots injured by the plum cur- 

 culio {Conotrachelus nenuphar^ and not by codling moth. The 

 control of the latter pest was therefore practically absolute. 



Russeted fruit as such was not included in the following data, 

 as this was common to checks and sprayed trees alike, but se- 

 vere deformity with russeting is given as an index of the amount 

 of severe injury incurred. No distinction has been made between 

 picked fruit and windfalls, as nearly all the fruit hung on the 



