Vol. 15—1961 - NorthEastern Weed Science Society

Plot size varied from 9 sq. ft. to 100 sq. ft. All granulars were
applied by hand from a glaas. jar with a perforatetitop using the "salt shaker"
technique. The sprays were applied with a one-gallon hand pump sprayer
equipped with a Teejet nozzle at the rate of 100 gallons of water por acre.
The rates used in the various tests ranged from 4 to 20 pounds active chemical
per acre.
In 1959 a total of seven experiments was conducted comparing DACTHAL
W-50 and G-IO(20/40)M granulars on crops and W-50, G-l.25(20/40)M, and G-l.25
(30/60)M granules on turf for the control of crabgrass. The G-l.25 granulea
were as effective as the W-50 for control of crabgrass in turf. The 10 per
cent granulars were significantly less effective than the W-50 in tests for
the control of weeds in crops. In a tomato transplant test three G-IOMgranules
with mesh sizes 20/40, 30/60, and 40/60 were compared with the W-50. The
performance of the G-IO granulars in this evaluation was much better than in
some of the earlier tests, but they were significantly less effective than the
W-50. There was not a significant difference between the performance of the
various granulars, but the trend was toward greater herbicioal efficiency with
the smaller ai.ad 8:ranule.
In 1960 eight tests were conducted comparing the W-50 with G-l.5, G-5,
and G-IO granules .with varying mesh sizes and water disin~egratingproperties.
In tests with transplanted and seeded annual flowers three formulations were
ranked in effectiveness for weed control. W-50 > G-l. 5(20/40)F > G-5(30/60)F.
The G-l.5 granule equalled the W-50 in one test. The G-5 product was signifi­
cantly less effective in two tests.
49.
In a test on snapbeans where the W-50 and five granulars were compared
the weed control obtained with the formulations was in the following order of
effectiveness: W-50 =G-5(30/60)F > G-5(20/40)F> G-IO(30/60)F =G-IO(20/40)F
=G-5(20/40)S.The mean weed control percentages based on estimates after 35
days at a dosage of 12 lb. per acre were 91, 91, 81, 74, 72, and 71, respectdvelye
In a test on broccoli significant differences in weed control effectiveness
of three formulations were demonstrated in the following decreasing order r . W-50,
G-5(20!40)F, andG-l0(30/60)F. The mean per cent woed control based on estimates
after 42 days at .a dosage of 8 lb .. per acre was 89, 65, and 51, respectively.
The following general conclusions can be drawn from this work: 1. In tests
for the control of crabgrass in turf and for control of weeds in annual flowers
the G;..1.5(20!40)F formulation was as effective as the W-50. 2. The G-5{30!60)F
granule in one crop test nearly equalled the performance of the W-50, but was
significantly less effective than theW-50 in another test .. 3. Herbicidal
efficiency of the granulars increased when the per cent active ingredient decreased.
4. Differ,snces in weed control ability due to mesh size and water'
disintegrating properties within G.-5 and G-lOformulations were variable; however
,small granules (40/60) combined. with fast water disintegrp..tion tended to
increase herbicidal effectiveness compared to large granules (20/40) with a slow
water disintegration rate.