Vol. 16—1962 - NorthEastern Weed Science Society

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CHEMICAIBFORWEEDINGrorJlM&i!.J
ON MUCKANDUPLANDSOILS
173
, R. D.Sweet, J.e. Cialone, R. HliIorgan
Department of Vegetable Crops,COrneil UlI.iversity
Potatoes are one of the leading inter-tilled crops of the Northeastern
United States. New York is second to Maine in total production. Although the
most concentrated area of production in NewYork is on Long Island, significant
concentrations of production exist in several upstate areas so that in total
there is about the same acreage, currently 44,000, in each region. -
Generally speaking, the Upstate regions have shorter spring and fall
. seasons than Long Island. Consequently, the crop is in the ground for only
three or four months as compared to four to six months 'on Long Island.
Furthermore, weeds such as annual grasses and nutgrass which germinate and grow
Vigorously only at warm temperatures start fairly soon 'after planting in
Ups1,;ate areas, but ~ not start for one or two months after planting on Long
Island. Upstate the potato plant especially on muck grows fairly rapidly and
is likely to provide heavy shade early in the season and continue to prOVide
shade until Just prior to harvest. In contrast, Long Island potatoes start
slOWly and, in addition, are often left in the field a month or two after the
.foliage has been drastically reduced in vigor.
The purpose of these tests was (A) to investigate under Upstate field conditions
the relative merits of selective herbicides which have been previously
reported satisfactory and (B) to evaluate new chemicals for their potent1ai as
selective herbicides. '
Field Testing of Herbicides
COllllllercial fields at two locations, one muck and the other gravelly loam
were chosen as sites for testing the relative merits of several herbicidal"
which had been reported as selective and effective in potato weed control., At
both 10catiotlS treatments were made pre-emergence Imd early post-emergence. In
the pre-emergence treatments, no eultivatiml was given except at hilling. The
other plots were cultivated normally. Post-emergence application was made a week
prior to "lay-by" on the muck, but on the mineral soil 'treating was actU8illy at
lay-by as far as the plots were concerned ewen though the crop was only 1 -' 4
inches tall. On muck, however, the plants were knee-high anda1lllost-'touoli1ng
bet_eli rows. The crop was planted on mineral so11 about May 22 and treated
June 1 at).d June 15. The muck crop was planted May " and treated May 24 and
June 28. There vere four replications with individual plots 3 x 15 feet pl.anted
to one row of crop.
Results of the pre-emergence applications on bOth soils are presented in
table 1. It can be seen from these data that muck so11 greatly reduced the
relative herbicidal effectiveness of several compounds. namely. Hercules 8043,
Dacthal) Zytron.and RobInand ~ F-34. Moderate eduction in herbicidal
effectiveness was noted for T1llam, Hercules 7531 and Dinitro granular and
liquid. Trietazine was inconsistent. On the other hand, CDEC+CDAAwas more