ONIONS IN THE CONNECTICUT VALLEY 31 



may be expected from the medium size sets (^ to % inch), because the crop 

 will be more uniform and of better quality, and because the initial outlay for 

 sets is less on account of the smaller number of bushels required for planting. 

 Sets smaller than x /i inch are too small for best results. 



4. A comparison was made between sets graded from Yi to % inch and those 

 from 3/8 to 7/8 inch. The yields of marketable bulbs were practically the same 

 from the two size groups, but there were more seed stalks, divided bulbs, and 

 small onions from the 3/8- to 7/8-inch group. The difference in price of the two 

 grades of sets would largely determine which to use. 



Experiments were conducted with methods of growing onion sets. The results 

 show that very good yields of sets of high quality may be obtained, that they can 

 be kept in storage without excessive loss from decay, sprouting, or shrinkage, 

 and that when planted they will produce satisfactory onions. From the experi- 

 ments it seems that about 50 pounds of seed to the acre drilled in a row about 

 2 inches wide, and fertilized with 500 to 1000 pounds of a good onion fertilizer, 

 will give good results. Careful judgment must be exercised in regard to the proper 

 time of pulling the sets. 



Selection and breeding of onions and the testing of varieties have been carried 

 on for the past ten years, in an attempt to find or produce varieties more suitable 

 to the Connecticut Valley than those now grown. Several strains have been inbred 

 for five generations, and some crosses have been made, but no strains of com T 

 mercial importance have been developed. In this work good results were obtained 

 by transplanting to the field young onions started in the greenhouse, and this 

 method is thought to have possibilities as a practical cultural method in the 

 Connecticut Valley. 



A short summary is included of previous work with some of the most important 

 of the diseases attacking onions in this region, together with recommendations 

 for treatment. 



Experiments with the control of onion thrips have shown the following: 



1. Set onions are a favorite breeding place for thrips, which migrate to near-by 

 fields of seed onions when the set onions are harvested. Seed onions grown at a 

 distance from set onions showed a much less severe infestation. 



2. In a study of different types of onions, it was found that those with upright 

 growth and an open chit were more resistant to the attack of thrips than those not 

 showing these characteristics. 



3. A fungus disease which is prevalent in some years helps to keep the thrips 

 in check. It is not a reliable control, however, since its presence seems to be 

 largely dependent upon the weather. 



4. A nicotine-soap spray has been tested over a period of years, under different 

 weather conditions and with various degrees of infestation, and has proved 

 uniformly successful in controlling thrips. At the height of the growing season, 

 reinfestation of the plants is very rapid and a follow-up spray is necessary, five or 

 six days after the first application. 



Publication of this Document Approved by Commission on Administration and Finance 

 3M-0-'35. No. 4807 



