Effects of different root promoting agents on the growth and root clump-ing formation of watermelon seedlings

MAO Guiling; YANG Zihao; CHENG Liao; YUAN Shan; ZHOU Jiale; GUO Xinyu; LI Jintao; HE Xinqi; LIU Guang; HE Changzheng; DAI Sihui

doi:10.16861/j.cnki.zggc.2024.0709

Abstract：In order to investigate the effect of root promoting agents on the rooting of plug seedling,watermelon variety SP100 was used as the test material.Different types and concentrations of root-promoting agent were sprayed,and water spraying was used as control.The effects of four root-promoting agents on the growth and root clumping formation of watermelon seedlings were analyzed,with the aim of screening out the root-promoting agent and its appropriate concen-tration beneficial to root clumping.The results showed that four root promoting agents,namely mineral source potassium fulvic acid,amino acid water-soluble fertilizer,Bacillus subtilis and indole naphthalene acetic acid,had a good promoting effect on the growth of watermelon seedlings and roots.They increased the plant height,stem thickness,leaf SPAD value,and dry and flesh mass of watermelon seedlings,and accelerated the speed of root clumping.According to the comprehen-sive analysis of relevant indexes of watermelon seedlings,the optimal concentrations of the four kinds of root promoting agents were as follows:Mineral potassium fulvic acid of 1000 mg·L-1,amino acid water-soluble fertilizer of 1000 mg·L-1,Bacillus subtilis of 600 mg·L-1,and indole naphthalene acetic acid of 80 mg·L-1.Through grey relational analysis,it can be known that among these four root-promoting agents,the one with the best effect on the growth of watermelon seed-lings and the clustering of roots is 600 mg·L-1 Bacillus subtilis,followed by 1000 mg·L-1 amino acid water-soluble fertil-izer.In summary,600 mg·L-1 Bacillus subtilis has the best promoting effect on the growth of watermelon seedlings and the formation of root clumping.