|Shrefler, James - OSU, LANE, OK|
Submitted to: Oklahoma Agriculture Experiment Station Departmental Publication
Publication Type: Experiment Station
Publication Acceptance Date: June 10, 2006
Publication Date: June 15, 2006
Citation: Webber III, C.L., Russo, V.M., Shrefler, J.W. 2006. Impact of preplant incorporated herbicides on non-pungent jalapeno pepper yields. 2005 Vegetable Trial Report, Oklahoma State University, Division of Agricultural Sciences and Natural Resources, Department of Horticulture and Landscape Architecture. Stillwater, OK. MP-164, p. 61-62. Technical Abstract: Producer surveys often rank weed competition as their most serious concern in maximizing vegetable yields. Non-pungent jalapeno peppers have a potential for outstanding yields in Oklahoma. Non-pungent jalapeno peppers are used for making commercial picante sauces (salsas). There is incomplete information on the crop safety of certain herbicides that may not specifically address their use with non-pungent jalapeno peppers. The objective of this research was to determine the weed control efficacy and safety of a combination of preplant incorporated herbicides on transplanted non-pungent jalapeno pepper production. A field study was conducted during the summer of 2005 on 36-inch (91-cm) wide raised beds at Lane, OK. Prior to constructing planting beds the soil was fertilized with 300 lb/ac of 17-17-17. The herbicides in the study included Devrinol (napropramide, 2 lb ai/a), Command (clomazone, 1 lb ai/a), Prefar (bensulide, 6 lb ai/a), and Treflan (trifluralin, 1lb ai/a) used separately, and in combination with one of the other herbicides. All herbicides were applied preplant incorporated just prior to transplanting on May 6, 2005. The herbicides were incorporated into the top 1 to 2 inches of the soil surface with a rolling cultivator. The experiment included a weedy (no weed control) and a weed-free (hand weeded) check. Pace 105 non-pungent jalapeno peppers were transplanted on May 6, 2005 with a 1.5-ft spacing between plants within the rows. Fruit were harvested on July 21, 2005, 76 days after transplanting. Plants treated with Command (clomazone, 1 lb ai/a) used by itself produced the greatest yields (7.32 t/a) compared to plants treated with the other herbicides used individually, although it was not significantly greater than Devrinol (napropramide, 2 lb ai/a), 4.11 t/a. Four of the five top yielding herbicide treatments included the use of Command (clomazone, 1 lb ai/a). The tank mixture of Devrinol (napropramide, 2 lb ai/a) and Prefar (bensulide, 6 lb ai/a) produced the second greatest yield (7.21 t/a). Herbicide treatments using Prefar (bensulide, 6 lb ai/a) or Treflan (trifluralin, 1lb ai/a) individually or in combination with each other resulted in significantly lower pepper yields, and were not significantly different from the weedy-check yields (1.07 t/a). The weed-free treatment produced 7.8 t/a compared to 86% yield reduction for the weedy check. These results demonstrated that Command (clomazone, 1 lb ai/a) used individually, or in combination with certain other herbicides, can maintain non-pungent jalapeno yields equivalent to weed-free levels. Devrinol (napropramide, 2 lb ai/a) also prevented significant yield loses due to weeds when applied in conjunction with Prefar (bensulide, 6 lb ai/a).