Tudy On The Mitigation Action Of Different Rootstocks On Greenhouse Watermelon Succession Cropping Obstacle

Watermelon(Citrullus lanatus) as an important horticultural crops, occupies an important position in the planting industry. But watermelon was a strictly avoid succession cropping crops, succession cropping obstacles have occurred often, seriously affecting the sound development of watermelon industry. At present, as an effective way to improve the watermelon continuous cropping, grafting has been widely used in production. The purpose of this study was to explore the mitigation of two different root-stock on greenhouse watermelon succession cropping obstacles, and provide a theoretical basis for future agricultural production.In this study, the greenhouse of four year succession cropping was chosen as the test field. There was three treatments: pumpkin/watermelon grafted(N), gourd/melon grafted(H), self-rooted(CK), measured the incidence of Fusarium Wilt of each growth period, the plant morphological and physiological indicators index of each growth period, the total soil microbial before and post-production, the fruit quality of watermelon. Obtained the following results:1. Two root-stocks, Pumpkins and gourds, had a significant role in promoting watermelon growth and development, and the promoting of pumpkin root-stock was better than gourd root-stock. In the later period of the growth, the difference of the main vine length between two treatments, and between treatment and contrast were significant in the order of pumpkin root-stock, gourd root-stock and self-rooted. The difference of both root-stock stem-diameters in the growth period was not significant, but compared with the contrast, the stem-diameter has reached a significant difference in the growth periods except seedling stage, pumpkin root-stock stem- diameter value 15.12 % higher in the mature period.2. In remission of Fusarium Wilt, there was not obvious deference between treatments and contrast in the effects of remission in the first two growth periods. In the later two periods of growth, though the difference between the two treatments was not significant, but all significantly lower than the contrast, pumpkin root-stocks was 16.44% lower than the contrast which was the highest value of Fusarium Wilt reduction in mature period.3. The two root-stocks improved the structure of microbial community in greenhouse watermelon continuous cropping, compared with before planting to harvest, the quantity of actinomycetes and bacteria(except gourd root-stock) increased significantly, while fungi significantly reduced. But the difference between the effects of the pumpkin root-stock and the gourd root-stock was not obvious. The increased number of fungi of the pumpkin root-stock was the least, lower 60% than the contrast. While the increased number of bacteria of pumpkin root-stock was the largest, doubled than the contrast. The total number of microorganism of pumpkin root-stock was the largest, which was 0.40×107 cfu/g; followed gourd root-stock increased 0.27×107 cfu/g; and the contrast increased the least, which was 0.21×107 cfu/g.4. The yield of pumpkin root-stock was significantly higher than the contrast, the difference between the gourd root-stock and contrast was not significant, but the value of gourd root-stock was higher than the contrast. Gourd root-stock significantly reduce the content of soluble solids, but the change of pumpkin root-stock was not obvious. The content of soluble protein and vitamin C of pumpkin root-stock was significantly higher than the contrast, the differences between gourd root-stock and contrast was not significant.