African star grass response to postemergence herbicides

ABSTRACT Cynodon nlemfuensis Vanderyst, commonly called African star grass, is excellent forage in pasture formation and herd feeding. However, little information is available regarding weed management in areas of star grasses. Two field experiments were carried out in 2017 and 2018 to evaluate the response of African star grass to postemergence herbicides. The treatments applied were as follows: 2,4-D (1,340.0 g ae ha-1); 2,4-D + picloram (720.0 +192.0 g ae ha-1 + 0.3% v/v nonionic surfactant); fluroxypyr + picloram (80.0 + 80.0 g ae ha-1 + 0.3% v/v mineral oil); fluroxypyr + aminopyralid (160.0 + 80.0 g ae ha-1 + 0.3% v/v mineral oil); fluroxypyr + triclopyr (320.0 + 960.0 g ae ha-1 + 0.3% v/v mineral oil); bentazon (720.0 g ai ha-1 + 0.5% v/v mineral oil); imazapyr (25.0 g ai ha-1); monosodium methyl arsenate (MSMA) (1,440.0 g ai ha-1 + 0.1% v/v nonionic surfactant); atrazine + S-metolachlor (1,480.0 + 1,160.0 g ai ha-1); atrazine + tembotrione (1,000.0 + 100.8 g ai ha-1 + 0.3% v/v mineral oil) and a control without herbicide application. The most phytotoxic treatments for the African star grass plants were fluroxypyr + amininopyralid, fluroxypyr + triclopyr and atrazine + tembotrione. The dry matter yield of star grass plants was not reduced by the applications of 2,4-D, 2,4-D + picloram, bentazon, imazapyr, MSMA and atrazine + S-metolachlor. These herbicides can be considered potential practices in African star grass crop management.

摘要 Cynodon nlemfuensis Vanderyst（俗称非洲星草，African star grass）是一种优质牧草，适用于草地建植与家畜饲喂。然而，目前针对非洲星草种植区杂草管理的研究资料仍较为匮乏。本研究于2017年和2018年开展了两项田间试验，以评估非洲星草对苗后除草剂的响应情况。试验设置的处理组如下：2,4-D（1340.0克酸当量/公顷）；2,4-D+氨氯吡啶酸（720.0+192.0克酸当量/公顷，添加0.3%体积比非离子表面活性剂）；氟草烟+氨氯吡啶酸（80.0+80.0克酸当量/公顷，添加0.3%体积比矿物油）；氟草烟+氨基吡啶酸（160.0+80.0克酸当量/公顷，添加0.3%体积比矿物油）；氟草烟+绿草定（320.0+960.0克酸当量/公顷，添加0.3%体积比矿物油）；苯达松（720.0克有效成分/公顷，添加0.5%体积比矿物油）；咪唑烟酸（25.0克有效成分/公顷）；甲基胂酸一钠（MSMA，1440.0克有效成分/公顷，添加0.1%体积比非离子表面活性剂）；莠去津+S-异丙甲草胺（1480.0+1160.0克有效成分/公顷）；莠去津+苯吡唑草酮（1000.0+100.8克有效成分/公顷，添加0.3%体积比矿物油）以及不施用除草剂的空白对照组。对非洲星草植株药害最为显著的处理组为氟草烟+氨基吡啶酸、氟草烟+绿草定与莠去津+苯吡唑草酮。施用2,4-D、2,4-D+氨氯吡啶酸、苯达松、咪唑烟酸、MSMA以及莠去津+S-异丙甲草胺均未降低非洲星草的干物质产量。上述除草剂可作为非洲星草种植田杂草管理的潜在可行方案。