Vol. 16—1962 - NorthEastern Weed Science Society

279
·QUACKGRASSCONTROL
S.M.
Raleigh l
Variation in genetic strains of quackgra's was very evident in
1961. These stiains can best be observed by applying treatments across
areas where corn bas been grown.. 'Cultivation tendlt'to spread strains
up and down the row. These strata. have been observed especially with
Atrazine, but also with Dalapon and Amitrol-T.
Plowing, preparing a ,•• ed bed, and planting the same day the
land is plowed followed by good 4ultivation will reduce the stand of
quackgrass considerably, especially if a chemical is used whicb is
injurious to q\lackgrass and not. to the corn.
The pre-emergence application of Atrazine at two pounds per
acre, (data in Table II) with A*1trol-T. Dalapon or Atrazine reducedtbe
stand of quackgrass very little.. In other fields where Atrazine was applied
as pre-emergence the day of planting, the quackgrass was reduced considerably.
Under these conditions rates of four pounds and higher did not give much,
better control than the two pound rates.
The control of quackgca•• with Dalapon (Table II) is rather poot.
In anotber field of twelve acre •. where Dalapon was used with and without
wett.ing agents, the control was much better. There were six replications.
The results were: Dalapon, 5.92.pounds alone (Dowpon, 8 pounds) 93%, with
Dash added, 96%; Dynawet, 97%; rab, 95%; liquid All, 93%; and Tritton x
100, 92%. Four pounds of Atrazine in this test save 90%control.
(l) Professor of Agronomy, The Pennsylvania State University, University Park,
Pennsylvania.