Belz Regina G, Duke Stephen O
Agroecology Unit, University of Hohenheim, Stuttgart, Germany.
Pest Manag Sci. 2014 May;70(5):698-707. doi: 10.1002/ps.3726. Epub 2014 Feb 22.
Herbicide hormesis is commonly observed at subtoxic doses of herbicides and other phytotoxins. The occurrence and magnitude of this phenomenon are influenced by plant growth stage and physiological status, environmental factors, the endpoint measured and the timing between treatment and endpoint measurement. The mechanism in some cases of herbicide hormesis appears to be related to the target site of the herbicide, whereas in other examples hormesis may be by overcompensation to moderate stress induced by the herbicides or a response to disturbed homeostasis. Theoretically, herbicide hormesis could be used in crop production, but this has been practical only in the case of the use of herbicides as sugar cane 'ripeners' to enhance sucrose accumulation. The many factors that can influence the occurrence, the magnitude and the dose range of hormetic increases in yield for most crops make it too unpredictable and risky as a production practice with the currently available knowledge. Herbicide hormesis can cause undesired effects in situations in which weeds are unintentionally exposed to hormetic doses (e.g. in adjacent fields, when shielded by crop vegetation). Some weeds that have evolved herbicide resistance may have hormetic responses to recommended herbicide application rates. Little is known about such effects under field conditions. A more complete understanding of herbicide hormesis is needed to exploit its potential benefits and to minimize its potential harmful effects in crop production.
除草剂刺激效应通常在除草剂和其他植物毒素的亚毒性剂量下被观察到。这种现象的发生及其程度受植物生长阶段和生理状态、环境因素、所测量的终点以及处理与终点测量之间的时间间隔影响。在某些除草剂刺激效应的情况下，其机制似乎与除草剂的靶位点有关，而在其他例子中，刺激效应可能是对除草剂诱导的适度胁迫的过度补偿或对体内平衡紊乱的一种反应。从理论上讲，除草剂刺激效应可用于作物生产，但这仅在将除草剂用作甘蔗“催熟剂”以提高蔗糖积累的情况下才具有实际应用价值。对于大多数作物而言，许多能够影响刺激效应的发生、程度以及产量增加的剂量范围的因素，使得依据目前所掌握的知识，将其作为一种生产实践过于不可预测且存在风险。在杂草无意间接触到刺激剂量（例如在相邻田地中，当被作物植被遮蔽时）的情况下，除草剂刺激效应可能会产生不良影响。一些已经进化出除草剂抗性的杂草可能对推荐的除草剂施用量产生刺激反应。在田间条件下，对此类影响了解甚少。需要对除草剂刺激效应有更全面的认识，以便在作物生产中发挥其潜在益处并将其潜在有害影响降至最低。
