Herbicides are an important tool for weed management in water-seeded rice (Oryza sativa L.); however, the reduced efficacy from available herbicides and the lack of new herbicides have encouraged research on new use of older herbicides for this production system. This research evaluated weed control and water-seeded rice response to pendimethalin applied post-emergence in a field trial. Pendimethalin was applied alone and in herbicide mixtures at 1.1, 2.3 and 4.4 kg ai ha−1 with three graminicide or broad-spectrum foliar herbicides to rice at the 4- to 5-leaf stage. A greenhouse study was conducted to evaluate rice response to pendimethalin applied at 1.1 and 2.3 kg ai ha−1 at the 4- to 5-leaf stage grown under 5-cm and 10-cm flood depth conditions. Grass weed control at 14 days after treatment was 68%–86% when pendimethalin was applied in herbicide mixtures compared to 48%–63% when applied alone. The mixtures with bispyribac-sodium and propanil provided broad spectrum control of grass, sedge, and broadleaf weeds unlike the mixture with cyhalofop-butyl, a graminicide herbicide. All treatments resulted up to 8% of visual rice injury. Rice tiller counts and grain yield were not affected by pendimethalin. The 5-cm and 10-cm flood depth, in the greenhouse study, affected shoot length, root length, and root biomass but not shoot biomass averaged over pendimethalin applications; however, rice was normal by 14 or 21 days after treatment. Only shoot length was reduced by 12% at 21 days after treatment at 3.4 kg ai ha−1 of pendimethalin. The results from these studies demonstrate pendimethalin can be a potential herbicide for water-seeded rice and does not cause injury of concern on rice when applied at the 4- to 5-leaf stage rice.

中文翻译：

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杂草和水稻对单独使用二甲戊灵和在水播稻中除草剂混合物施用的反应


除草剂是水稻 （Oryza sativa L.） 杂草管理的重要工具;然而，现有除草剂的功效降低和新除草剂的缺乏鼓励了对旧除草剂在该生产系统中新用途的研究。本研究在田间试验中评估了杂草控制和水稻对出苗后二甲戊灵的反应。二甲戊灵单独施用，并在 1.1、2.3 和 4.4 kg ai ha-1 的除草剂混合物中施用，与三种禾谷杀虫剂或广谱叶面除草剂一起施用在 4 至 5 叶期的水稻上。进行了一项温室研究，以评估水稻在 5 厘米和 10 厘米洪水深度条件下生长的 4 至 5 叶期施用 1.1 和 2.3 公斤二甲戊灵的反应。在除草剂混合物中施用二甲戊灵时，处理后 14 天的禾本科杂草控制率为 68%-86%，而单独施用时为 48%-63%。与杀禾本科除草剂 cyhalofop-butyl 的混合物不同，与 bispyribac-sodium 和 propanil 的混合物不同，它们对草、莎草和阔叶杂草提供了广谱控制。所有治疗都导致高达 8% 的 Rice 视觉损伤。水稻分蘖数和产量不受二甲戊灵的影响。在温室研究中，5 cm 和 10 cm 洪水深度影响了芽长、根长和根生物量，但不影响二甲戊灵施用的平均芽生物量;然而，Rice 在治疗后 14 或 21 天恢复正常。在 3.4 kg ai ha-1 的二甲戊灵处理后 21 天，仅芽长减少了 12%。这些研究的结果表明，二甲戊灵可以成为水播水稻的潜在除草剂，并且在 4 至 5 叶期水稻施用时不会对水稻造成令人担忧的伤害。