Herbicides for Control of Major Weeds on Winter Potato Fields in Fujian

  Objective  To determine the appropriate weed control using herbicides on fields of winter potatoes in Fujian.

  Methods  Major species of weeds found in the areas and the applicable herbicides for controlling them were studied. A random block test was applied to evaluate the efficacies of oxadiazone, butachlor, acetochlor, s-metolachlor, quizalofop-p-ethyl, haloxyfop, and rimsulfuron on Favorite.

  Results  More than 20 varieties of weeds were commonly found on the fields that grew winter potatoes in the province. Among them, Stellaria media , Malachium aquaticum, Chenopodium album, Chenopodium serotinum, Polygonum bungeanum, Polygonum lapathifolium, Digitaria sanguinalis, Portulaca oleracea, Solanum nigrum, and Conyza canadensis accounted over 80% of all. In the weed control efficacy tests on 7 herbicides, metolachlor at 960 g·L⁻¹ application rate, 60% butachlor, and 50% acetochlor were considered most desirable. The calculated 45 d relative control effects based on fresh weed weight were 83.7% for metolachlor, 68.4% for butachlor, and 65.4% for acetochlor. On the post-seedling efficacy, the 25% sulfadisulfuron-methyl water dispersible granules exhibited the best relative control of 90.9%, among all herbicides tested.

  Conclusion  The weeds in the field were diverse in variety. The application of metolachlor at 960 g·L⁻¹ or 25% sulfadisulfuron-methyl water dispersible granules appeared to be most effective in weed control on the winter potato fields in Fujian.