Herbicide Screening

 The following information was derived from the most recent trial in
which new herbicides were evaluated (Everglades Station Mimeo Report 60-7).
Diamond Alkali Company DAC-893 and Dow M-1329 had sufficient promise in crop
tolerance and herbicidal performance to warrant further critical evaluation
as pre-emergence herbicides. Robm & Haas FW-734 was an effective post emer-
gence material which tilled all crops but rice. Certain post emergence
herbicide-crop combinations should be tested further in directional applica-
tions. In a comparison of 15 herbicides, crop tolerance was greater and
weed control poorer with granular than with liquid formulations at the same
active ingredient rate. Randox and Vegadex were the only herbicides in which
both formulations were equal herbicidally. Granular amiben was a better herbi-
cide than the liquid formulation.


Primary evaluation of herbicides for leaf crops

 Thirty-five chemical treatments were made by applying different for-
 mulations, rates and combinations of three herbicides over 18 types and varie-
 ties of leaf crops. The crops tolerated CIPC and Vegadex better than Randox.
 Randox and Vegadex provided the best weed control. Romaine was injured by
 Vegadex. Pink-ribbed endive was severely injured by Randox although green-
 ribbed endive grew normally. Three strains of Great Lakes lettuce were less
 tolerant to the herbicides than Cornell 456. The Boston lettuces differed in
 tolerance.

 No firm conclusions may be drawn from this exploratory trial except
 that the three herbicides mentioned should be used with caution under field
 conditions. Additional research is planned to develop herbicidal treatments,
 methods and recommendations satisfactory for commercial use.


 Herbicides for sweet corn

 Pre-emergence

 Corn stand, emergence and growth were normal following pre-
 emergence applications of recommended herbicides. Highest yields were obtained
 with Simazine, Vegadex, Randao-T and Randox. Best control of grass and brcad-
 leaf weeds was provided by Randox, Randox-T and Vegadex. When applied at the
 recommended rates (Everglades Station Mimeo Report 60-3) to a 12-inch band in
 corn planted on 36-inch centers, these treatments would cost from $3.25 to
 6.50 per acre of corn.

 Post emergence

 The best control of emerged grass and broadleaf weeds in corn
 at four weeks after planting was provided by combinations of the following
 herbicides: Karsil, Atrazine, and DNBP. Corn was most tolerant of Atrazine
 or DNBP alone. However, the best yields were produced in plots treated with
 Atrazine, Atrazine + DNBP, DNBP,or Karsil + Randax. None of these are
 recommended for commercial use currently. Similar trials are planned to'
 develop effective, safe post emergence treatments.