1922.] PUBLIC DOCUMENT — No. 31. 19a 



]\LvXA(iEMEXT. 



Department of Poinolofiii. 



Project 4. "Experiments in ])ruiiijig apples." 



Professor Sii.vw. 



These experiments were started in 1910, and compare the 

 following methods of pruning apple trees: globular or vase 

 head, modified leader head, a new form of the true leader 

 heafl, and unpruned head. Results to date confirm the growing 

 belief that pruning is a dwarfing process, and that heading 

 back is detrimental to fruit-bud formation. 



Project 9. "Testing methods of pruning." 

 Project 10. "Testing of pruning methods on Northern Spy 

 and other varieties." 



Professor Shaw. 



These are similar to the above in scope. Project 9 is carried 

 out iu connection with Project S, "Test of cover crops for 

 apple orchards." 



Crop Protection. 



Insect Enemies of Vegetation. 

 Department of Entomology. 



Project 2. "Economic importance of digger wasps." 



Professor Fernald, 



This project was started in 1909, and represents an attempt 

 to establish the economic importance of the digger wasps and 

 to determine the number and kinds of insects which may be 

 parasitized by them. This project is nearing completion. 



Project 3. "Control of the onion maggot." 



iVssistant Professor Bourne. 



Work on this project has progressed to the point where the 

 possibility of poisoning the onion maggot fly before completion 

 of oviposition has been established. Owing to the seasonal 

 nature of the onion maggot attacks, and to the difficulty of 

 getting comparable results on areas widely separated, it has 

 not yet been possible to organize field test work on an effective 

 scale. 



