| Abstract: In order to cultivate strong watermelon seedlings and reduce the waste of water and fertilizer resources, the precision control experiments of water and fertilizer were carried out by control the different water content of substrates (95%-100%, 70%-75%) and use different water-soluble fertilizers including potassium dihydrogen phosphate and balanced fertilizer of nitrogen, phosphorus and potassium (15-15-15+TE) on the grafted seedlings of watermelon. The survival condition, growth indexes and strong seedling index of grafted seedlings were compared and analyzed. The results showed that when the grafted seedlings of watermelon were cultivated in winter and spring of greenhouse, it was suitable for keeping the maximum water content of the substrate at 95%-100% within seven days after grafting, and appropriate to apply potassium
dihydrogen phosphate water-soluble fertilizer 1 000 times solution four times (at the rootstock with one true leaf, the grafted seedling with one true leaf, the scion with one-leaf and one-heart, and the scion with two-leaf and one-heart, respectively). The survival rate of grafted seedling was increased (95%), the rate of diseased
seedlings was decreased (5%), and the strong seedling index was 165.59, which was significantly higher than the other three treatments and was beneficial to the cultivation of strong watermelon seedlings. |