Daniel I. Padgett, Glenn R. Wehtje, Veronique Perrin, and Neil R. Martin, Jr.

The introduction of Cadre to the assortment of herbicides currently available in peanut production has opened new doors for weed control. Cadre offers control of many troublesome broadleaf and grass weeds that are left unchecked by Pursuit, a herbicide with similar chemistry that has been available the to peanut growers past few years.

Cadre has a wide window of application timing, but for maximum performance it is recommended that it be applied at a rate of four ounces per acre (all rates are expressed in formulated product, not active ingredient) at early post emergence (EPOST) before the weeds exceed two to three inches in height. For several years, mixtures of Starfire with Butyrac 200 and/or Basagran have been widely used for weed management in peanuts, but this standard may change with addition of new herbicides to the peanut market place. Starfire is registered for post emergence (POST) application on peanuts between emergence and 28 days after peanut emergence, a relatively limited window of application. Basagran and/or Butyrac 200 are often added as a tank mixture in order to control weeds that may escape Starfire, such as smallflower morningglory, coffee senna, prickly sida, and bristly starbur. Also, the addition of Basagran reduces the amount of Starfire-induced injury to the peanut plants.

An AAES study evaluated and compared Starfire-based herbicide programs with systems containing Cadre for weed control, peanut yield, and net returns when used in Alabama peanut production systems. Ongoing experiments are being conducted at the Wire grass Substation in Headland. The first year's data are discussed here.

Natural populations of yellow nutsedge, bristly starbur, sicklepod, Texas panicum, and Florida beggarweed infested the experimental plots. Prowl was applied (one quart per acre) preplant incorporated (PPI) over the entire test area and incorporated to a depth of 2.5 inches one day before planting Florunner peanuts.

Six EPOST-applied and four POST-applied treatments were arranged with all possible combinations. EPOST treatments included (1) none, (2) Starfire, (3) Cadre at two ounces per acre, (4) Cadre at four ounces per acre, (5) Starfire plus (tank-mixed) Cadre at two ounces per acre, and (6) Starfire plus Cadre at four ounces per acre. The POST treatments were: (1) none, (2) Butyrac 200, (3) Starfire plus Basagran, and (4) Starfire plus Basagran and Butyrac 200. Starfire, Basagran, and Butyrac 200 were applied at 11, 16, and 16 ounces per acre, respectively, at both EPOST and POST applications. Visual estimates of weed control were recorded at periodic intervals throughout the growing season.

Test plot data on inputs and yield were evaluated at the farm production scale level using enterprise budgets developed by the Alabama Cooperative Extension Service for nonirrigated peanut production. Peanut net return calculations were based upon the assumption that the crop would have a normal grade and be marketed at a 3:1 ratio of quota peanuts and additional peanuts. Prices for quota and additional peanuts were $610 and $300 per ton, respectively.

Yellow nutsedge control was rated at a greater than 90% for Cadre at both the two or four ounces per acre rate applied alone, regardless of whether a POST treatment was used. Control of Florida beggarweed, sicklepod, and bristly starbur was similar, thus only an average rating for these broadleaf weeds is presented. As seen in previous studies and this study, both an EPOST and POST treatment was required for maximum (greater than 90%) weed control; this was also true for the maximum yield and maximum net returns. Starfire applied EPOST followed by Starfire plus Basagran plus Butyrac 200 provided this level of control. However, nearly all the treatments in which Cadre was applied EPOST at four ounces per acre followed by any POST application that contained Starfire provided comparable weed control.

Starfire is fairly competitive with Cadre with respect to weed control, yet maximum yields and net returns reflected the application of Cadre. Maximum yield and net return was achieved with Cadre applied alone EPOST, at either the two or four ounces per acre rate, followed by a POST application of a Starfire, Butyrac 200, and Basagran tank mixture. For both maximum weed control and maximum yield to be obtained, it was required that both an EPOST and POST herbicide application be utilized.

These results reveal the excellent weed control and yield-preserving benefits of this recently registered herbicide. Yet, two separate herbicide applications were required for maximum weed control, yield, and net return. Further research involving split application of Cadre at two ounces per acre for both EPOST and POST may show the practice to be equally if not more effective than the best treatment of this study.

Padgett is a Graduate Research Assistant and Wehtje is a Professor of Agronomy and Soils. Perrin is a Graduate Research Assistant and Martin is a Professor of Agricultural Economics and Rural Sociology.