Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms.

1. The allelopathy of black walnut trees can prevent other plants from growing near them.
   黑胡桃樹的化感作用可以阻止其他植物在它們附近生長。
2. Some plants use allelopathy to inhibit the growth of competitors and gain more resources.
   一些植物通過化感作用抑制競爭者的生長，從而獲取更多的資源。