Vol. 15—1961 - NorthEastern Weed Science Society

The following effects were noted.
1. Seed Treatments - 0, 40 and 80 lbs. of 5% Thiram-5% Ethion granular per
acre based on 15 inch rows. Applied with the seed in the drill.
a. The 40 and 80 lb. seed treatment rates reduced the numbers and total
weight of marketable fresh onions. The 80 lb. rate had an adverse
effect on all measurements when compared to the untreated check.
It is probable that diseases or insects were of no significant importance
in this trial.
2. Herbicides - 13 treatments including 2 untreated checks applied preemergence.
a. Of particular interest is the onion stand reduction resulting from
the use of 12 lbs. liquid Randox per acre. Due to a heavy seeding
rate the remaining plants were sufficient to produce top yields.
b. CIPC did not affect onion stand counts but produced low onion
yields. This may be attributed to the competition of a heavy
crabgrass and goosegrass population that CIPC did not control.
c. Comparisons of liquid and granular mixtures of CIPC and Randox
indicate that the liquid mixture reduced onion stand count
whereas the granular mixture did not.
3. Irrigation - 0, 1 and 2 inches additional water applied 2 days after
herbicide application.
Since irrigation levels were not randomized, no valid conclusions could be
drawn. The following effects are worthy of note, however.
a. The land 2 inch levels of irrigation reducHd onion stands.
This stand reduction resulted in increased marketable yields at
the 1 and 2 inch level --- probably due to the elimination of
competition between onion plants.
4. Interaction of Seed Treatment, Herbicides and Irrigation on Onion Stand
and Yield.
a. For these measurements there were in most instances interactions
for irrigation x herbicide and irrigation x seed treatment. In
no instance was there a significant interaction for herbicide
x seed treatment.
b. In general yields were increased by those factors that reduced
onion stand count. An exception would be the no seed treatment
plots which practically always outperformed the treated areas,
in stand count and yields.
c. Interactions of irrigation x seed treatment x herbicide showed a
marked reduction in onion stand at the 2 inch irrigation level
where Randox :iquid, Randox granular, Randox + CIPC granular and
Randox T liquid were used. This effect was noted at all levels
nf irrigation where 12 lbs. of Randox liquid or 6 Ibs. of granular
Randox was used in conjunction with the 80 lb. seed treatment rate.
d. Randox T granular at 6 lbs. ha9 little effect on stand count for
the factors studied.