ONIONS IN THE CONNECTICUT VALLEY 11 



bushels per acre. With the exception of biennial sweet clover, growth was almost 

 invariably good, grasses and clovers reaching a height of 3 or 4 inches, and rye 

 6 to 8 inches, before plowing in late fall. 



With the exception of redtop all the cover crops depressed the yield of onions 

 on the average, although there were years when gains were shown. The results 

 were quite erratic, and the differences are not considered significant. It is interest- 

 ing to note in this connection that redtop has proved the most satisfactory cover 

 crcp for tobacco in a separate series of experiments. 1 



It was found more or less difficult to cure onions in the presence of cover crops. 

 Usually they were raked to a check plot without cover crop for curing, a method 

 which would hardly be practicable on a large field. On a large scale the use of 

 curing crates would probably be the most practicable method. Crates were tried 

 in this experiment, but it was found that the onions did not cure quite so well in 

 this way as on the ground. 



This experiment has shown that it is possible to grow cover crops in the culture 

 of seed onions in the Connecticut Valley. The cover crops, with one possible 

 exception, have not proved beneficial to yield of onions, but this may be because 

 the soil on which they were tried was a little better supplied with organic matter 

 than the average onion soil. The cost of seed and additional labor in handling 

 during curing are disadvantages of cover crops. Prevention or checking of water 

 and wind erosion, particularly the latter, checking of losses of plant food by 

 leaching, and increasing or maintaining the organic matter of soils, are possible 

 advantages. Most likely, the use of cover crops would be more feasible and the 

 advantage greater with set than with seed onions. 



SPACING AND RATE OF SEEDING ONIONS 2 



As a result of observations made during preceding seasons relative to the effect 

 of density of stand on the occurrence of onion "blast", a field test was conducted 

 in 1929 for the purpose of obtaining further information on this point. Rows 

 were spaced 13, 15, and 18 inches apart and it was planned to seed at the rate 

 of 3, 5, and 7 pounds per acre. The field chosen for this work was quite uniform, 

 and was uniformly fertilized with 2500 pounds of a 4-12-8 fertilizer. Each treat- 

 ment was replicated four times. 



The seeding was done May 11 at the actual rate of 3.5, 4.5, and 6.85 pounds 

 per acre instead of 3, 5, and 7 pounds as planned. The different rates of seeding 

 became very obvious soon after the onions came up and remained quite noticeable 

 throughout the season. During July the number of plants on 90 feet of row were 

 counted on each plot. The figures are given in Table 1, as well as the average 

 number of seeds planted per foot and the average percentage which survived. 

 Onions seeded at the heaviest rate matured about two weeks earlier than those 

 seeded at the lightest rate. The wider spacing of rows also slightly retarded 

 maturity. The crop was harvested 132 days after seeding, although some plots 

 were still somewhat green. 



Since there was no blast on onions during the season of 1929, the results were a 

 failure so far as the effect of density of stand on blast was concerned; but there 



Beaumont, A. B., Snell, M. E. and Holland, E. B. The effect of certain cropping systems on 

 the yield and quality of Havana tobacco. Mass. Agr. Exp. Sta. Bui. 297 (1933). 



2 Credit is due L. H. Jones and other members of the Botany Department for suggestions in 

 planning the experiment. 



