l6 MAINE AG.RICULTURAI, KXl'KRIMENT STATION. I9I4. 



Colorado, but here the results are brought about through the 

 action of the alkali in the soil or irrigation water converting the 

 insoluble lead arsenate into soluble compounds."'' So far as the 

 writer has been able to learn no evidence of similar action has 

 been observed in the East. As a matter of fact the amounts of 

 lead arsenate advocated for use alone are not materially greater 

 than now used in combination with fungicides like lime-sulphur. 



Russeting of fruit. One fact has been strikingly brought out 

 in the experiments conducted during the past season which has 

 been evident to a greater or less degree during preceding years. 

 This is that much russeting of the fruit may be due to natural 

 causes and all of it should by no means be charged against the 

 spiay material. Mr. Bonns observed this in 1910 and com- 

 mented on it in the first report of the series. t 



In 1913 a large amount of russeting was observed, even on 

 the unsprayed plot which showed over 31 per cent of the 

 fruit so affected. In this connection it is interesting to note 

 that russeting was actually less on the plot where 2 pounds of 

 powdered lead arsenate was used than on the check. However 

 on some of the other plots, particularly the one sprayed with 

 bordeaux mixture it was very evident that the treatment applied, 

 directly influenced the amount of injury obtained. 



There is no doubt that the excessive amount of russeting 

 which occurred the past season irrespective of the treatment 

 was in some way associated with the climatic conditions which 

 prevailed when the fruit was small. While there was an ab- 

 sence of the so-called ''frost bands" on the fruit it is very prob- 

 able that late frosts associated with heavy winds and' cold rains 

 were directly responsible for the trouble. 



Arsenite of zinc with lime-sulphur. \^ery little comment is 

 necessary with regard to the results obtained with this combina- 

 tion in 1913. In 1912 it was used with perfect safety on both 

 foliage and fruit and was so reported. While practically no 

 russeting of the fruit could be attributed to it in 19 13, when 

 compared with the check plot, the foliage injury alneady 



* Headden, Wm. P., Arsenical Poisoning of Fruit Trees. Bui. Colo. 

 Arg. Exp. Sta. 131, 1908. 



t Bonns, W .W., Orchard Spraying Experiments. Bui. Me. Agl. Exp. 

 Sta. 189, 191 1. 



