农用有机硅对五氟磺草胺防治稗草的增效作用

为明确有机硅对五氟磺草胺防治稗草的增效作用和增效机理,本研究采用室内与田间试验测定有机硅助剂对五氟磺草胺的增效作用,并采用滴重法和HPLC方法分别探索有机硅对五氟磺草胺药液表面张力和吸收的影响。室内生测表明,有机硅对五氟磺草胺防治稗草具有显著的增效作用。当五氟磺草胺用量为7.5 g/hm^2,有机硅添加浓度为0.04%时,稗草的致死率和干重抑制率分别提高32.0百分点和39.6百分点;有机硅用量与增效效果非正相关。田间试验表明,有机硅对五氟磺草胺增效作用明显,对五氟磺草胺低剂量的增幅优于其高剂量的增幅;机理研究表明有机硅能够显著降低五氟磺草胺溶液的表面张力,增强稗草叶面对五氟磺草胺的吸收。

Synergism of organosilicon on Echinochloa crus-galli control with penoxsulam

In order to understand synergistic effect and mechanism of organosilicon on barnyard grass control with penoxsulam, greenhouse and field experiments were conducted, and drop weight and high performance liquid chromatography (HPLC) methods were adopted to investigate effect of organosilicon adjuvant on liquid surface tension and uptake of penoxsulam. Indoor experiment showed that organosilicon significantly synergized penoxsulam, with increase of 32.0 percentage points in plant mortality and 39.6 percentage points in inhibition rate of dry weight when penoxsulam was used at 7.5 g/hm2, and organosilicon concentration was 0.04%, compared to penoxsulam treatment alone. Moreover, organosilicon concentration was not positively correlated to its synergism efficacy. Field experiment revealed that organosilicon had better synergism at the lower penoxsulam rate than that at the higher rate. Organosilicon evidently reduced surface tension of penoxsulam solution and enhanced uptake of penoxsulam in barnyard grass leaves.