Vol. 15—1961 - NorthEastern Weed Science Society

359.
THEEFFE0TIVENESSOF PRE-E.II4EBGENCE APPLICATIONSOF HERBICIDESFORWEED
CONTROLIN OATSANDTBE ESTABLISBMENrOF FORAGESEEDINGS
Stanford N. Fert'ig !I
(A 'Summary Report)
INTRODUCTION:
Since the introduction of selective herbicides in 1945, hundreds of
compounds have been screened and field tested for weed control in small
grains and the associated forage seedings.
, A wide range of weed species can be effectively controlled by compounds
such as 2,~-D, MCP, 2,4,5-TP and 4(2,4-DB) when applied aspost'-emergence
sprays. However, the important legume species are in a susceptibility grouping
less resistant than many of the commonweed species. The degree of injury to
the legume stand is a variable factor influenced by time of treatment, the
nature of the canopy to protect it, climatic conditions, the volume of water
used in application, the degree of competition offered by the small grain and
the interval of this competition.
This study was initiated to investigate the effectiveness ot herbicides
applied pre-emergence to the oats and the legume species for controlling the
commonweed species prevalent in oats and to determine the susceptibility of
alfalfa to the kind and rate ot chemicals used.
EXPERIMENTAL lviETHOD ANDPROCEDURE:
On May 14, 1958 certified Rodney oats were planted in a randomized plot
design with 5 replications of each treatment. All plots were then seeded to
DuPuits alfalfa at 10 pounds per acre using a Brillion cultipacker seeder.
To establish a uniform stand of broad-leaved weeds, all plots were over-seeded
with 10 pounds of mustard (Brassica kaber) per acre using a Wheel-barrow seeder.
On May 21, the chemicals listed in Table I were applied as pre-emergence
sprays. All treatments were applied in 30 gallons of water per acre.
The chemicals, rates used) yield of oats for 1958 and the forage yields
for 1959 are reported in Table I.
RESULTSANDDISCUSSION:
The emergence of oats was normal on all plots except those treated with
Fenuron and the ; and 4 pound rates of Eptam. At all rates of Fenuron, the
emergence of oats was slower and the plants showed a chlorat ic condition at
emergence. The entire stand ot oats on these plots was dead Within 3 weeks after
emer~nce.
_ Y P:rotessor of Agronomy1 Cornell Univers ity, Ithaca, New York.