Effects of drip irrigation fertilization on growth, yield and quality of fruit mulberry in facilities cultivation

【Objective】 The effects of different fertilization treatments on the growth, development, yield and quality of fruit mulberry under drip irrigation were studied, which provided theoretical reference for guiding the efficient utilization and management of water and fertilizer of fruit mulberry in facilities.【Method】 Fruit mulberry Da 10 in 11 years under 150 plants in 667 m²+secondary branch shaping mode as the test materials, under the condition of same drip irrigation, set up five different fertilizer treatments［T1:fertilizing amount with drip irrigation 100%, T2:fertilizing amount with drip irrigation 80%, T3:fertilizing amount with drip irrigation 60%, T4:fertilizing amount with drip irrigation 40%, control (CK):conventional hole fertilizing amount 100%］. Two consecutive years of field positioning tests were conducted. The effects of different fertilization levels on growth and development, yield and quality of fruit mulberry under drip irrigation were analyzed, and the fuzzy mathematics subordinate function value method was used for comprehensive evaluation. 【Result】 The growth of branch and leaf, and yield of mulberry fruit under 60%, 80% and 100% fertilizing amount with drip irrigation were all higher than CK, among which the leaf weight, single berry weight and single plant berry yield were increased by 11.55%-27.06%, 10.24%-14.44% and 15.07%-24.64% respectively compared with CK, and the single berry weight was significantly higher than that of CK(P<0.05, the same below). There was no significant difference between the number of germination branches and berry shape index in different treatments(P>0.05, the same below). In addition, the pH, flavonoid and anthocyanin contents of mulberry fruits under 60%, 80% and 100% fertilizing amount with drip irrigation were significantly higher than CK, which were increased by respectively 1.58%-3.17%, 21.94%-35.61% and 25.00%-62.50%. However, the soluble solids and soluble sugar contents were respectively 0.83%-1.42% and 1.72%-4.39% higher than CK, but the difference was not significant. The content of polyphenols in 80% and 100% fertilizing amount with drip irrigation was significantly higher than that in 60% fertilizing amount with drip irrigation and CK, which were respectively 14.78% and 12.56% higher than CK. The content of polyphenols in 60% fertilizing amount with drip irrigation was 3.45% higher than CK. The index values of 40% fertilizing amount with drip irrigation were all lower than CK or not obviously different from CK. The fuzzy mathematics subordinate function value method was used for comprehensive evaluation on the economic characters and nutritional quality of fruit mulberry under different fertilization treatments. The comprehensive evaluation sequence was T1>T2>T3>CK>T4. The comprehensive performance of more than 60% fertilizing amount with drip irrigation was obviously better than that of the conventional hole fertilizing amount 100%. 【Conclusion】 The results show that compared with the conventional hole fertilizing amount 100%, more than 60% fertilizing amount with drip irrigation is beneficial to promote the growth of branches and leaves of fruit mulberry, improve the yield and quality of mulberry fruit, and save fertilizer and increase yield obviously. It should be popularized and applied in production practice.