Vol. 15—1961 - NorthEastern Weed Science Society

·205.
Percen t Woad Can trol
·1960
Broedleat: Annual
Her-b Le Lde weeds grasses
6 pounds Dacthal 58.3
8 pounds Dacthal 68.8
1 pound Trietazine 91.6
2 pounds Trietazine ·92.3
In 1959, 1.80 inches of ra.in fell during the first ten days
after treatments had been applied; in 1960, .12 inches fell during
the first ten days. Total rainfa 11 in 1959 for the first twenty
days following application of treatment was 5.17 inches, in 1960
2.32 inches.
The 'poor weed control obtained in 1960 tests with Dacthal
apparently resulted from insufficient rainfall. The poor weed
control in 1959 with 1 and 2 pounds Trietazine csn be .attributed
to high rainfall reducing effectiveness of the relatively low
rates of application by excessive leaching. The 4 pound rate of
Trietazine in 1959 gave 97.8 percent can trol of broad leaf weeds
and 24.7 percent control of annual grasses.
B. Comparisons of Several Rates of DNBP-DALA~ON Mixtures with
C~codYlicAcid, Falone, and Dlchlorobenzonitrile
None of the treatments produced yields significantly higher
than 3 pounds DUBPplUS 2.22 pounds of Dalapon, although 3 pounds
DNBPplus 4.44 pounds Dalapon, and 8 pounds. of Falone gave
numerically higher yields, Table 6. Eight pounds of cacodylic
acid did not .satisfactorily control broadlesf weeds, Table 7.
D:LchloX'obertzon1trlle 'at both 2 and 4 pound rates inhibited sprouting
and reduced the stand of potatoes.
C. Cowarison ofa mr;§p-DALAPONMixture with Thiolcarbal11ates
None of'the thiolcarbamates tested produoed yields of
Katahdin potatoes signifieantly higher than 3 pounds DNBPplUS
2.22 pounds Dalapon, Table 8. Three pounds DNBPplUS 2.22.pounds
Dalapon, and 6 pounds R-l607 (n-propyl-di-n-propylthiolcarbamate)
produced significantly higher yields than 6 pounds of R-2061
(propyl-ethyl-n-butyl thiolcarbamate). Six pounds EPTC did not
differ significantly in effect on yield for ef, ther the DNBP­
Dalapon mixture or for ~-l607.
The DNBP~Dalapon mixture gave significantly better broadleaf
weed control-than R~l607'or R-206l, but did not differ significantly
from EFTC.