Sulfentrazone absorption by plant roots increases as soil or solution pH decreases
Sulfentrazone absorption by plant roots increases as soil or solution pH decreases
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DOI：
10.1614/p2002-149
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发表时间：
2003-09-01
期刊：
影响因子：
2.5
通讯作者：
Vencill, WK
中科院分区：
文献类型：
--
作者：
Ferrell, JA;Witt, WW;Vencill, WK
甲磺草胺是一种除草剂，已被观察到以不可预测的方式损害作物。因此，进行实验以确定甲磺草胺的根吸收是否依赖于生根培养基的pH。研究开始检查整个植物从土壤和水培溶液中吸收甲磺草胺，以及在溶液中的离体根。这些实验表明，蒸腾作用随着土壤pH值的降低和除草剂用量的增加而降低;我们的目的是用这种措施来描述除草剂的伤害。同样，植物生长24小时的C-14-甲磺草胺溶液培养溶液中积累了更大的除草剂浓度在根溶液pH值下降到6.5以下。当切下的棉花根放置在含有C-14-甲磺草胺的水培溶液中持续10至120分钟时，再次证明了这种随着溶液pH值降低而吸收增加的趋势。然而，当切下的根被放置在含有弱酸性除草剂草甘膦的溶液中时，没有观察到吸收增加的趋势，随着溶液pH值的变化。因此，可以得出结论，随着甲磺草胺从离子形式转化为中性形式，伴随的溶解度的变化是负责增加植物根系的吸收。土壤pH值的局部差异可能是甲磺草胺吸收量增加的原因，并解释了观察到的不可预测的伤害模式。
Sulfentrazone is a herbicide that has been observed to injure crops in an unpredictable manner. Therefore, experiments were conducted to determine whether root absorption of sulfentrazone was dependent on the pH of the rooting medium. Studies were initiated to examine sulfentrazone uptake of whole plants from soil and hydroponic solution, as well of excised roots in solution. These experiments demonstrated that transpiration decreased as soil pH decreased and herbicide rate increased; it was our intention to use this measure as a description of herbicide injury. Likewise, plants grown for 24 h in C-14-sulfentrazone hydroponic solution accumulated a greater herbicide concentration in roots as solution pH decreased below 6.5. This trend of increased absorption with reduced solution pH was again demonstrated when excised cotton roots were placed for durations of 10 to 120 min in hydroponic solution containing C-14-sulfentrazone. However, when excised roots were placed in solution containing the weak acid herbicide glyphosate, no trend of increased absorption was observed with changes in solution pH. Therefore, it was concluded that the accompanying change in solubility, as sulfentrazone was converted from the ionic to the neutral form, was responsible for the increased absorption by plant roots. Localized differences in soil pH could be responsible for greater sulfentrazone uptake and explain the unpredictable patterns of injury that have been observed.