早在1965年，荷兰人deWit就提出了一个杂草与作物竞争的数学模型，其研究竞争关系的“置换试验法”至今仍被杂草科学工作者所采用。近年来，国际上数学模型在杂草科学研究中的应用已极其普遍。运用数学模型的方法，可以定量地来分析杂草的发生、生长、分布，及其对作物产量的损失 As early as 1965, deWit of the Netherlands proposed a mathematical model of competition between weeds and crops. The “displacement test method” for studying competition has so far been adopted by weed scientists. In recent years, the international application of mathematical models in weed science has become extremely common. Using mathematical models, we can quantitatively analyze the occurrence, growth, distribution of weeds and their loss of crop yield