Vol. 16—1962 - NorthEastern Weed Science Society

Rototilling was done in June·' SO that the 1959 and 1960 data represents
re-establishment over the period June 1960 to November 1961. In the fall of
1959 three months after treatnumt little Agropyron repens was present in
the plots receiving simazine or atrazine. This was true also in November
1961 following June 1961 rototilling.
Summary
In a Dunkirk' silty c1B¥ 101$ simazine and atraZine applied on the SUI"­
face at 5 poundS or at 10 pounds' of active ingredient per acre are effective
in controlling Agr0J2.:'Lr.cnr~pens'antt'seedling wceds'ror one and possibly 'biro
growing seasons. Ro'';;otiJling 2- 3 times at the closE! of the second aeason
largely reduces any herbicidal value and permits nomal growth of red kidney
beans during the sensi.tive juvdhileleaf' stage on through to flowering stage.
Normal growth of all indicator plants tested is taken to indicate that the
soil is free of herbicidal leveis Of the herbicide applied. Incorporation
of simazine or atrazine at the tfm~ of application increases the initial
efficiency of the herbicidala.ctibh.It is ljJ~ely that incorporation
assures placement within the soil. and minimizes loss through run off or '
spreading to adjacent plots. ao~dtilling once a year in present tests
appears to be as effective as herbicidal appEcatj,on used once in a three
y'ear period. Weed control value is lost and phytotoxic effect to indicator
plants was not evident after the second year following application.
:References
Pridhem, A. M. S. Crop, voed !Uld.~oi1 aspects of sil'nazine, atrazine and'
other herbicides in greenhouse and field tests. Proc. 14th
Almual Meeting N.E. Weed Control conr , 142-147. 1960.
•
-----a~:t~r~a~z~i·ne
Weed control. and residual effects
applied to. sod prior to planting
of simazine and of
nursery stock.
Proc. 15th Annual MeetiDg R.E. Weed Control Conf. 174-176.
1961.