1. The excessive use of pesticides can result in the accumulation of phytotoxicants in the soil, which can harm crops.
过度使用农药会导致植物毒害物质在土壤中积累，从而对作物造成伤害。

2. Researchers are studying the effects of different phytotoxicants on plant growth and development.
研究人员正在研究不同的植物毒素对植物生长发育的影响。