Water demand law of newly introduced varieties of watermelon and fruit yield and quality in different nursery techniques

【Objective】To study the water consumption pattern，soil water dynamics，yield and quality of watermelon of newly introduced varieties cultivated on pressed sand，and the optimal varieties were selected to provide scientific reference for large-scale light and simplified cultivation of watermelon in the arid zone of central Ningxia.【Method】Used comparative experimental research method to study the fertility water demand pattern，yield and quality of four varieties of 4 watermelon varieties（NK-TM，R-18，N-08 and DD-87）under the same irrigation quota and fertilization conditions with different seedling techniques（self-rooting and grafting），and analyzed the variability of the above indicators in different treatments.【Result】Precipitation and irrigation had obvious effects on soil water content changes. The soil volumetric water content increased greatly in each treatment after irrigation and after rain，and most of the soil volumetric water content remained at about 13.0% in other states. The water consumption in the seedling stage was dominated by evaporation. The daily water consumption of self-rooted seedlings and grafted seedlings was 0.60-1.94 mm；the daily water consumption of the spreading stage was 1.19-1.74 mm. The water consumption during the flowering and fruit sitting period increased greatly, and the daily water consumption reached the peak, which was 4.34-8.57 mm. The daily water consumption in the puffed melon stage gradually decreased to 2.95-3.77 mm；the daily water consumption in the watermelon mature stage was the smallest，0.95-1.59 mm. The water consumption of grafted watermelon seedlings was higher than that of self-rooted seedlings except for the seedling stage. The yield of grafted watermelon seedlings was higher than that of self-rooted seedlings. The yields of grafted watermelon seedlings of varieties R-18 and N-08 were higher，which were 43766.61 and 41745.13 kg/ha，respectively. But in terms of watermelon quality indicators，self-rooted seedlings were obviously better than grafted seedlings. Among all treatments，the peel of N-08 grafted seedlings was the thinnest，only 8.33 mm. The results of correlation analysis showed that under the same water and fertilizer conditions，watermelon yield was extremely significantly correlated with seedling-raising methods and crop water consumption（P<0.01），and there was a significant negative correlation between total acid content and varieties，and between vitamin C content and crop water consumption （P<0.05）.【Conclusion】The yield and quality of the four newly introduced watermelon varieties planted in the sandy land are closely related to water consumption and seedling raising methods. N-08 grafted seedlings has excellent performance and can be planted in the arid zone of central Ningxia.