Vol. 16—1962 - NorthEastern Weed Science Society

Results
Date treated: 9/6/61
Soil motsture:medium below, but dry on lurfaQe and 1n seed zone.
Soil type: sandy clay loam
Plot arrangement: One row of each crop was planted on a 3,ft. bed
110 ft. long.
Herbicide treat.ents: All herbicidel were apPl1e4 beginning at the rate
of 16 lbs/A and decreasing to 1/2 lb/A with a half dosage distance of
20 ft., using 125 gals/acre at 40 psi. The width of the sprayed area
was about 5 ft. There was no cultivation or haRd weeding.
Rainfall data: 0.52 in. the d4Y prior to makina the beds and planti.,.
Soil surface and seed zone dried out rapidly and remained dry until Sept.
14 when 0.67 in. fell. Subsequent precipitatiollduring the 4 weeks dter
planting was: Sept. 15, 0.14 in.; Sept. 18-20, 0.35 in., Sept. 28,
0.40 in.; and OCt. 2-4, 1.98 inl.
and Observations
Visual observations and measurements are summariced in Table 1. There were
several herbicides besides the standard treatmenta WhiChshowed promising degrees
of crop·weed selectivity. The material with the wid.. t safety margin on most
crops was Dacthal, giving good initial weed control to 1 lb/A while showing no
crop injury at the highest rate of 16 lbs/A. except on apinach which waa tolerant
below 4 lbs/A. R·1870 was equally safe on moat cropa including spinach, at
l6lba/A, but 6 lba/A were required for good weed control. Other materials
showing good selectivity on most crops teated were Trifluralin (, to 3 lba/A),
Tilla. (4 to 8 lha/A) and Eptam (4 to 8 lba/A except on spinach). Zytron
(4 to 6 lbs/A), Randox (3 to 4 lba/A) and NIA 6370 (8 to 12 lbs/A) showed "limited
possibilities on apecific crops.
It is obvious that the dry and hot weather cond1clons at the time of appli·
cation and for 8 daya afterward had a major influence on the results. Unuaually
high ratea, eapecially of the thio~carbamates, were aece.aary for good weed
control. However, crop tolerance also resulted at correspondingly high rat.l.
Increased efficiency from theae materiala, as well al Vegadex and CIPC, has
consiltently been obtained when foll~ed by rain or Iprinkling. Trifluralla,
Diphenamid, Zytron and Dscthal, on the other hand, are apparently not so subject
to volatilization and loss under adverle weather and 8011 conditions. Othew teats
show. however, that Dacthal is very dependant on precipitation getting it into
the aoil before the weed seeds ge~lnate.
Trial No.2: Pre· ... rgence herbicide applicationl 08 six leaf cropa ustng
conventional plots.
Methods and Materials
Crop varieuea:
Spinach - Old Dominion Blight Resiatant
Kale • Vates Dwarf Blue Curled Scotch
Hanover salad - Early
Collards - Vates
Turnip areens • Seven Ton Salad
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