Vol. 15—1961 - NorthEastern Weed Science Society

312.
THEEFFECTIVENESSOF COMBINATIONS OF PLOW-mIN, PRE-EMERGENCE AND
ANDPOST·EMERGENCE TREATMENTS lOR QUACK GRASSCONTROL, 1960 RESULTS.
INTRODUCTION:
Stanford N. Fertig !t
(A SumrDaryReport)
The most prevalent grass problem on NewYork farms is Q,uackgrass
(Agro:pyron rep!ns) In small graiDS, corn, potatoes and vegetable production,
it is a menacing problem. Heavy infestations compete vigorously for moisture
and nutrients, resulting in losses in yield and qUality.
EXPERIMENTALMP:rHODANDPROCEDURE:
The herbicides listed in Table 1 were applied as plow·down and preand
post-emergence trea.tments in the spring of 1960. As indicated in the table,
all plots received a plow-down treatment. These were followed by pre- or postemergence
treatments to the corn.
The chemicals were applied to vigorously growing Quackgrass (4 to 6
inches tall)
on June 4.
on May 6. The areas were plowed on June 3 and planted. t9 corn
The pre-emergence treatments were applied on June 8 and the post-emergence
treatments on June 28.'
All treatments 'Were replicated 4 times and all chemicals applied in
30 gallons of water per acre.
In all instances, one -half of each plot was cultivated two times. The
first cultdvation 'V.as3 weeks after planting and the second, 1 weeks after
planting.
~ESUUTS ANDDISCUSSION:
The stand of Quackgrass was markedly reduced by all chemicals and combinations
of treatment, particularly when combined with two cultivations. The
stand counts (Table 2) show the added effectiveness of two cultivations in
reducing the stand of Quackgrass.
Based on stand counts J yields of silage corn and observations during
the growing season tbe most promising treatments were 3, 4, 7, 8, II, 12 and
13·
The competitive effect of heavy stands of Quackgrass on corn yields
are shown in Table 2. The average ;yields are below normal due to late p1an.tiDg
(June 4) and an early harvest (September 19). However, the differences 1n
;yield are significant and show the competitive effect of QU8.ckgrass on corn.
The 1960 growing season was exceptionally cool but with ample moisture.
V Professor of Agronomy, Cornell University, Ithaca, N. Y.