60 NEBRASKA STATE HORTICULTURAL SOCIETY. 



wheather in combination with the early or late spraying or with 

 both, showed comparatively little rust. In fact, with the Jona- 

 than trees the spraying of May 7 was the only one that proved 

 to be of any particular value. Trees sprayed at this time show- 

 ed an average of thirteen rust spots per hundred leaves as against 

 an average of 111 rust spots per hundred leaves for unsprayed 

 trees and 112 spots for all trees sprayed at times other than 

 May 7. 



This experence is of great practical importance. The results 

 show conclusively that spraying at the wrong time, no matter 

 how thoroughly done, is useless, while spraying at the proper 

 time gives excellent results. Of course it is not to be assumed 

 from this that spraying on this particular date in early 

 May will give the best results every year. What we should 

 learn from this test is that we must watch the "apples" on the 

 cedar trees and spray nonresistant varieties of apple trees thor- 

 oughly as soon as the cedar apples have begun to enlarge, be- 

 come gelatinous and orange-colored, the changes which indicate 

 that the rust spores will soon be spreading the infection broad- 

 cast. 



RESULTS OF SPRAYING FOR SCAB. 



The results of spraying for apple scab are shown in the follow- 

 ing table: 



