Vol. 15—1961 - NorthEastern Weed Science Society

357.
THEEFFECTOF HERBICIDESONTHEYIELDOF ESTABLISHEDALFALFA
.Am>BIRDSFOOl'TREFOIL
Stanford N. Fertig y
(A SummaryReport)
INTRODUCTION:
The yield and quality of hev produced on NewYork farms is far below
the desirable or easily obtainable level. This is the result of at least
four factors: (1) the seeding miXtures used by many farmers is inferior to
that which they should be us 1ng, (2) stands are left down much longer than
desirable, (;) the time of cutting is much too late on most farms" resulting
in reduced quality and total seasonal yields and (4) most legume stands have
a serious infestation of broad-leaved weeds.
Changes 1n farming practices" based on presently available research information,
of present
could be put into use by farmers to materially improve the quality
forage., For example, e. wider use of grass silage would result in
better quality roughage, more total tons of feed which animals would consume
and at the same time reduce the weed problem on farms by eliminating a major
source of re-infestation.
EXPERlMENTAL METHODANDPROCEDURE:
A series of' plots which were seeded to alfalfa and birdsfoot trefoil
in the sprinS of 1951 were used for this study. The stand of both legumes
was uniformily good on all plots. The varieties were Narragansett and Viking"
respectively.
On April 25, 1959, when the alfalfa was 2 to , inches tall and the birds ..
foot trefoil 1 to 2 inches tall, the chemicals listed in Table I were applied.
RESULTSANDDISCUSSION:
The initial injury to the alfalfa was more severe than to the birdsfoot
trefoil. The early growth was reduced by all treatments and delayed blooming
until the week of July 29. The yield of any cutting taken in June would
have been very low,; however, the recovery on the second cuttilg would have
been more rapid and complete.
The early growth was reduced by all treatments with 2,4,5-TP at 1/2
pound and 4(2,4 ..00) ester (ACPM-,60) at 2 and ; pounds being most severe.
The injury to the legume stand was evidenced by stunting, reduced thickened
leaflets and epinasty of the plant stems. .
The recovery of the birdsfoot trefoil was more rapid than the alfalfa.
HoweverJ some injury symptoms were evident on both crops at harvest (JUly 29)
at the higher rates of each chemical and rate.
Y Professor of Agronomy, Cornell University" Ithaca" NewYork.