I. SPRAYING. 



JOHN CRAIG. 



The "Spray Calendar" originated at the Cornell Agricultural Ex- 

 periment Station. In 1894, Prof. M. V. Slingerland devised the first 

 tabular calendar arrangement of -spraying suggestions; this was printed 

 and used at Farmers' Institutes. In February 1895, this Experiment 

 Station published a "Spray Calendar" prepared by E. G. Lodeman, late 

 instructor in the Department of Horticulture. Since that time, the 

 spray calendar has appeared in many forms and under the authority of 

 many writers and institutions. The Cornell publication has been changed 

 from the chart to the pamphlet form. 



Every year there is a distinct demand for the type of information 

 furnished by this calendar. Fruit-growers and farmers realize more 

 clearly when planting season comes that success depends as much upon 

 the application of intelligent methods to the combating of plant parasites 

 as upon the management of the soil. 



The Need of Spraying. 



The annual loss arising from the incursions of destructive insects in 

 the United States exceed by many times the yearly output of all the 

 gold mines in the United States. The reduction in the value of the apple 

 crop of New York state due to insect .injury, cannot be less than thirty 

 per cent per year. This is a heavy tax on the fruit-grower. The injury, 

 however, could be lessened at least fifty per cent by an expenditure of 

 not exceeding two per cent on the value of an average apple crop. The 

 need for spraying is therefore evident. This need will probably increase 

 as time goes on. 



The Principles of Spraying. 



Plants, unlike animals, are not cured of diseases by medical treat- 

 ment. Moreover, they cannot be made immune to insect or fungous 

 attacks by previous treatment. We aim by spraying to protect plants 

 from two classes of enemies, insects and fungi. We merely protect 

 plants; we do not cure them. How are they protected? By covering 

 the foliage with a medium in which the fungus will not grow, in the case 



