4 EXPERIMENT STATION BULLETIN. 



lirne (or G pounds kydrated lime), 4 pounds copper sulphate and 50 

 gallons water. 



GENERAL TERMS 



Check plbt or tree. Trees or plants which are left untreated to indi- 

 cate the amount of injury by insects or disease that would develop when 

 not sprayed or dusted. 



Count trees. In much of the work, particularly with apples, the fruit 

 from one or more trees in each plot was sorted and classified according 

 to the presence of any injury by insect or disease or by its freedom from 

 such injury. Trees were selected for this purpose that w-ere as uni- 

 form as possible. Location of the tree and the size and - uniformity of 

 the crop were points considered in selecting them. The number of trees 

 in any plot was in no case limited to the trees from which counts were 

 actually made. The total number in a plot varied from nine to fifty 

 or more. 



Pink or cluster application. The application made on apples just be- 

 fore the blossoms open, but after the buds have separated in the clus- 

 ter. 



Calyx application. In the work here reported the calyx application 

 was usually made immediately after the petals . had fallen. It could 

 be safely delayed a few days and still control the coddling moth but 

 earlier application insures better control of apple scab. 



Other Insects. This term is used in several of the tables showing re- 

 sults of work with apples. This means injury to the fruit by any chew- 

 ing insect other than coddling moth, such as the lesser apple worm, Tus- 

 sock moth, fruit worms, etc. 



Calcium arsenate. The same as arsenate of lime or arsenate of cal- 

 cium. 



ACKNOWLEDGMENTS 



Much of this work was done at several places in the state in orchards 

 belonging to fruit growers. The Horticultural Department is indebted 

 to these growers for their assistance and co-operation in carrying on 

 this work. They are Geo. Winegar & Son, Morrice; B. F. Hall, Beld- 

 ing ; Oscar Braman, Grand Rapids ; C. W. Garlock, Grand Ledge ; James 

 Boyce, Holland; J. C. Maynard and Ed. O'Brien, Grand Rapids. Much 

 of the actual work with experiments on the College grounds was done 

 by Harold Lackey. The duster used at the College was furnished by 

 the Corona Chemical Company, Milwaukee, Wisconsin. R. E. Loree 

 and M. M. Brown assisted in securing records in 1918. The picture 

 on the front cover is used by the courtesy of D. F. Fisher of the United 

 States Department of Agriculture. 



