Vol. 15—1961 - NorthEastern Weed Science Society

PROGRESSREPORTON LAY-BYUEEDCONTROLIN POTATOES
Richard D. Ilnicki l, John C. Campbel1 2,
Thomas F. Tisdell 3, and Henry A. Collins
4
ABSTRACT
Annual grasses, particularly crabgrass and barnyard grass,
are a problem in potato production after the last cultivation.
These grasses do not necessarily reduce yields but are trouble­
some at harvest.. There has been a search for herbicides that
would effectively control these grasses and other weeds from
lay-by to early fall when potatoes are harvested. Many have
been either ineffective or have reduced potato yields. The
object of this study was to evaluate some of the newer herbi­
cides for weed control after lay-by.
After the last cultivation the following herbicides were
applied: ethyl N,N-di-n-propylthiolcarbamate (EPTC), n-propyl
di-n-propylthiolcarbamate (R-1607), ethyl ethyl-n-butylthiolcarbamate
(R-2060), and propyl ethyl-n-butylthiolcarbamate.
(R-206l) at 4 and 6 lb./A of a 5% granular formulation and 6 Ib/A
of the emulsifiable concentrate; 3-amino-2,5-dichlorobenzoic acid
(amiben, 5% granular)( tris (2,.4-dichloro Phenox yeth YI) phosphite
(falone, 10% granular) and N-I naphthylphthalamic acid, sodium
salt (NPA, 10% granular) at 4 lb./A; dimethyl 2,3,5,6-tetrachloroteraphthalate
(dacthal, 5%granular) at 6 and 12 lb/A;
and Hercules 7442 (H-7442, 5% granular) at 2, 4, and 6 lb./A.
Almost complete weed control was obtained with amiben and
the high rate of granular R-1607. Other effective treatments
included the high rates of granUlar R-2061 and EPTC. The
liquid formulations of all the thiolcarbamates were ineffective.
Notwithstanding that some of the other herbicides showed promise
they were ineffective for weed control at the rates used in this
study.
No treatment significantly increased or reduced yields of
potatoes from the control.
55.
IAssociate Research" Specialist in Weed Control, New Jersey
Agricultural Experiment Station, Department of Farm Crops,
Rutgers--the State University, New BrunSWick, New Jersey.
2Associate Research Specialist, New Jersey Agricultural
Experiment Station, Department of Plant Pathology, Rutgers-­
the State University.
3 and 4 Research Assistants, Department of Farm Crops.