plant growth retardant

例句：

1. 1. The chemical is usedto prevent the growth of harmful weeds in agricultural fields.
   这种化学物质用于防止农业田地中有害杂草的生长。
2. 2. The plant growthretardant helps plants to grow moreslowly and efficiently.
   这种植物生长延缓剂有助于植物生长得更加缓慢和高效。
3. 3. Theuse of plant growth retardants hasbeen banned in many countries due to concernsabout their environmental impact.
   由于对它们环境影响的担忧，许多国家已经禁止使用植物生长延缓剂。