SPRAYING TREES IN BLOSSOM 49 



SPRAYING AND THE WEATHER 



According 1 to Professor J. B. Smith, spraying with 

 the arsenites alone "should not be done in the middle 

 of a very hot day, nor, if it can be avoided, on a very 

 hot sultry day. A hot sun on recently sprayed foliage 

 will bring out all the caustic property in the poison 

 applied, and will cause injury. After the moisture 

 has evaporated, and only the thin film, of dry poison 

 remains, the sun does not act further on it. On a 

 cool day spray at any hour. On a hot day spray during 

 the early morning or late in the afternoon." These 

 precautions are not necessary, however, when arsen- 

 ate of lead is used. 



Frequent rains often occur during the spraying 

 season, and fruit-growers are sometimes tempted to 

 defer operations till dry weather, but according to the 

 experience of Mr W. J. Green, it is better, in the case 

 of the Bordeaux mixture at least, "to keep the work 

 going than to wait for dry weather. Of course it 

 would be impracticable to spray during a rain-storm, 

 nor would it be best to spray immediately before, but 

 if the mixture has two or three hours in which to dry 

 before a rain, it will adhere so closely that but little of 

 it will be washed off. Much of it will remain for 

 weeks, even during rainy weather." 



SPRAYING TREES IN BLOSSOM 



It is commonly believed that spraying trees in 

 blossom, in case the arsenites are used, endangers the 

 lives of the bees visiting the blossoms. In some 

 regions laws to prevent this have been enacted. 

 Spraying at such times seems unnecessary, and intel- 

 ligent fruit-growers would not practice it. The bees 

 are essential to the production of fruit, and there is 

 no excuse for destroying them. 



