Vol. 15—1961 - NorthEastern Weed Science Society

INTRODUCIIOB:
THEEFFECTOF WEEDCOMPET1'.rION ANDTHETIMEOF CHEMICAL TBEATMENT
ONOATYIELDSANDTHE EFFECTONLEGUMESTANDANDYIELD
Stanford N. Fertig y
(A SW1IDlaryReport)
A valuable aid in helping to sell a weed control program to farmers 18
to have available, accurate research evidence on the losses due to weed
competition and the returns which can be expected from recommendad practices.
Significant questions include: the effect of various weed popula.tion densities
on crop yields, when the competition occurs and in the case of small grains used
as a companion crop with legume seedings, the effect on legume establishment
and subsequent yields. Accurate data of this nature is necessary to determine
the level of costs farmers can economically afford to invest in mechanical and
chemical control methods.
EXPERIMEfllTALMETHODANDPROCE~:
In the spring of 1957 and 1958, field experiments weN initiated to investigate
the effect of weed competition on oats, the effect of removing the
competition at various growth stages of the oats by the use of herbicides or
hand-weeding and to study the resulting effects of weed competition on legume
stand establishment· and yield of forage.
The experimental design was a randomized block with 5 replications of
each cbem1eal or cultural treatment.
The plots were seeded to oats a.t 1-1/2 bushels per acre in early May.
Immedia.tely atter drilling the oats, the entire plot area was seeded to DuPuits
alfalfa at 10 pounds per acre and 4 of the 5 blocks were broadcast seeded with
10 pounds of wild mustard (Brassice. kaber), using a wheel-barrow type seeder.
The treatment schedule included plots seeded to mustard at 10 pounds per
acre and treated with Dinitro amine, 2, 4-D amine and MCPamine at weekly intervals
from emergence of the oats to 7 weeks atter emergence. These chemically
weeded plots were compared to plots seeded to mustard and hand-weeded at weekly
intervals plus those not seeded to mustard, but also hand-weeded. Plots seeded
to mustard and not weeded, plus plots not seeded to mustard and not weeded were
included in each block for comparison.
Due to rainy weather and the time required for the hand-weeding operation,
the weekly schedule was not exactly maintained. However, in only two instances
was the spraying or hand-weeding schedule delayed longer than the 1-day interval.
Y Professor of Agronomy, Cornell University, Ithaca, NewYork.