在激烈的市场竞争中，越来越多的农民在种植蜜瓜、西瓜的品种选择上趋向于中、高档品种。可是这类品种价格昂贵，农民为了节省种子开支，每穴只播1粒种籽，保苗率只有70％～80％，甚至更低。即使每穴种2位以上，受种子发芽率、墒情以及病、虫、鼠害等影响，也很难捉全苗，而且 In the fierce market competition, more and more peasants tend to choose mid- and high-grade varieties for planting melon and watermelon. However, these varieties are expensive. In order to save seed expenses, farmers only need to sow one seed per hole, and the seedling protection rate is only 70% -80% or even lower. Even if more than 2 per hole, affected by seed germination rate, soil moisture and diseases, insects, rodents, etc., it is difficult to catch full seedlings, and