Vol. 16—1962 - NorthEastern Weed Science Society

62
Du R)nt 326 caused slight early stunting of carrots on muck. However, at
barvest no differences in yield could be noted. In tbe t'WOtests on coarse
sand where only early records we~.btained, 326 caused marked stunting at
three pounds. It was for this reasOn that rates were kept at 1.5 lbs. ma.x1mum
in the sandy !oem test.
Ragweed is a severe pest not controlled by Stoddard Solvent. Tbe t'WO
tests abandoned early, were in fields chosen primarily because of bigh ragweed
population. These tests yielded some data on ragweed control. The follow1nc
materials failed to control tbis pest: Cbloro !PC, Dacthsl, Zytran, Dipropalin
(post-emergence) and Trifiuralin. Du R)nt 326 gave excellent control of
ragweed. Other compounds whicb performed well were J:.pazine and Solan.
In the planting on the sandy loam soil annual grasses were a serious problem.
Ipe.zine and Solan gave only fair control of tbese pests. Du R)nt 326, however,
performed exceedingly well. Tbus for a wide range of weed species on widely
different soils under either pre or post-emergent conditions this chemical was
outstanding.
Nutgrass
Ex,per1ments
The activity of Du Pont 326 and other chemicals was studied at two locations
beavily infested witb nutgrass. The materials were applied pre-planting at botb
locations. At one location they were also applied in the "spike" stage and wben
tbe nutgrass averaged 6 - 8 inches tall. The results of the several tests are
presented in table 2.
Timing bad a pronounced effect on the response of nutgrass to Du R)nt 326.
Pre-plant applications whether on the surface or incorporated gave unsatisfactory
control. Disappointing results were also bad from the "spike" stage applications.
At both of these timings the foliage turned somewhat yellow and early
growtb was slightly retarded. However, after about three weeks tbe nutgrass
foliage returned to a normal color and the plants developed vigorously. When
treated at the taller stage, the foliage turned yellow and gradually became
necrotic. No regrowtb occurred on any 326 plot treated at the 6 - 8 inch stage.
Atrazine performed less satisfactorily at the spike stage than is normally
expected. EPrC, however, was consistently excellent. Dalapon gave widely
different results at tbe two pre-plant locations. Tbe authors do not have any
explanation for the poor early results ~b Dalapon at King Ferry. Generally,
early applications witb Dalapon have givfn results similar to tbose obtained
at Binghamton.
ReSponse of Additional
Crops
In addition to the results already reported Du R)nt 326 was used as an
at -planting treatment in one test on muck, three tests on sandy loam, and in
three tests on stony silt loam. R)tatoes appeared to be tolerant, however, no
post -emergent tests have been conducted on this crop. Other crops including
cucumbers, muskmelons, peas, snap and lima beans, tomatoes, beets and spinach
were either severely damaged or killed at rates needed for weed control. Squasb
were moderately damaged from pre-emergence applications but were killed by