Submitted to: Subtropical Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 1997
Publication Date: N/A
Interpretive Summary: Cilantro, dill, and dandelion greens are used for salads and seasonings and are produced in many areas of the United States but there are no currently labeled herbicides for these crops. Mechanical and hand-weeding are very expensive and cost ranges from $250-$500 per acre and the expense of these types of weed control is a major threat to the continued production and producer profitability. Weeds not only decrease yield due to competition, but even moderate weed infestations can make harvested foliage unmarketable. The objectives of this study were to determine the crop safety and weed efficacy of trifluralin for weed control in cilantro, dill, and dandelion. Trifluralin at 0.56 and 0.84 kg/ha effectively controlled most winter weeds and did not adversely affect crop growth of cilantro and dill. Dandelion greens were severely stunted in two of three study sites with trifluralin. Trifluralin, when used in combination with early season mechanical cultivation, can provide selective weed control of many of the most common winter annual weeds in south Texas while exhibiting a high level of crop tolerance for cilantro and dill.
Technical Abstract: Field studies were conducted to determine the efficacy and crop safety of trifluralin in coriander, dill and dandelion greens when applied pre-plant incorporated (PPI) at 0.56 and 0.84 kg ha-1. Visual injury evaluations, crop fresh and dry weight at maturity, and leaf area were used to determine adverse effects of trifluralin on each crop when compared to an untreated control. Dandelion greens had a 47% and 49% reduction in leaf area when treated with trifluralin at 0.56 and 0.84 kg a.i. ha-1 when compared to the untreated weed free dandelion treatment. Coriander and dill showed no visual crop phytotoxicity and no adverse affects on crop growth, fresh and dry weight yield, or leaf area when treated with trifluralin. Trifluralin, when used in combination with early season mechanical cultivation, can provide selective weed control of many of the most common winter annual weeds in south Texas while exhibiting a high level of crop tolerance for coriander and dill.