Vol. 51—1997 - NorthEastern Weed Science Society

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MECHANICAL WEED CONTROL IN OATS
WITH A ROTARY HOE AND TINE WEEDER
Charles L. Mohler and James C. Frisch!
ABSTRACT
Four w management treatments were applied to oats in a randomized block design: 2,4-
0, cultivati pre-emergence and at the 2-3 leaf stage with a rotary hoe, cultivation with a flextine
weedin harrow at the same stages, and an untreated check. Cultivation controlled annual
weeds more effectively than 2,4-0 in one year, 2,4-0 was more effective in one year, and the
two approac es were about equal in a third year. The rotary hoe and tine weeder also varied in
relative eff tiveness. Cultivation reduced crop density in two of three years. Despite significant
differences' weed control and crop density, oat yields varied little among treatments in all three
years. Alth ugh integrated strategies might improve weed control, weed management efforts
may have li e economic benefit in this crop.
INTRODUCTION
Oats are grown on over 100,000 acres per year in New York state (8), making them about
tied with w eat as the number two grain crop after com. Sixty percent of this acreage is treated
with 2,4-0, 0% with Bromoxynil or MCPA, and 30% is not treated for weeds (1). Because of
possible ri associated with use of 2,4-0 (3,4), determining the effectiveness of alternative
weed contr practices for oats is desirable.
Spike to th harrows have been used to mechanically control weeds in small grain crops for
many years. Recently, European manufacturers have developed improved harrow designs using
flexible tine (tine weeders). Several investigations in Europe and elsewhere have found that
these devic s reduce weed density with little damage to small grain crops (9, 12, 13). Rasmussen
(10) found close correlation between weed control by harrowing and damage to small grain
crops, and veloped a model to explore these factors affected crop yield (11). Tine weeders
have been t sted in the United States for weed management in vegetable and row crops (2, 6, 14),
but little w has evaluated their effectiveness in small grain production systems in the U.S.
oes have long been used for early season weed control in row crops in the U. S.
However, e have found no data on use of rotary hoes in small grains. This lack of research on
rotary hoes small grain crops may be the result of their rarity in Europe (1. Ascard, personal
communica .on) where most research on mechanical weed control in small grains has occurred.
The stu y reported here compared weed biomass, oat stand and oat yield in four treatments
differing 0 y in weed control practice: (1) two operations with a rotary hoe, (2) two operations
with a tine eeder, (3) 2,4-0 applied at late tillering/early stem elongation, and (4) and untreated
control.
ISr. Res. soc. and Res. Assist., Div. of Biological Sciences, Sect. of Ecology and Systematics,
Corson Hal, Cornell University, Ithaca, NY 14853.