LIBRARY OF THE 



Massachusetts Agrvc*Hufal CoUeee. 



AMHEWST. MASS. 



massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 207 APRIL, 1922 



Injury to Foliage by Arsenical Sprays 



I. The Lead Arsenates 



By H. T. FERNALD and A. I. BOURNE 



It has long been known that arsenical poisons sprayed upon 

 foliage will at times produce injury or a "burning" of the 

 leaves. To find out why this burning takes place was the 

 purpose of the experiments reported in this bulletin. The in- 

 vestigation has shown that injury from the use of reliable 

 arsenicals is due to a combination of temperature, light and 

 humidity factors, and that spraying is safer in clear than in 

 cloudy weather. It has also established certain limits of 

 temperature and humidity within which spraying with the lead 

 arsenates seems to be entirely safe. 



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AGRICULTURAL EXPERIMENT STATION 



AMHERST, MASS. 



