Effects of polyacrylamide copolymer on growth of flowering Chinese cabbage in laterite soil

Different dose of polyacrylamide copolymer was applied to flowering Chinese cabbage, in order to study the effect of polyacrylamide copolymer on the the plant growth and water utilization efficiency, and to provide reference for copolymer applying on the vegetables cultivated in laterite soil of Hainan province. The results showed that the growth status of plant applied copolymers was better than the control (without application of copolymer), and the treatment of 4 kg per 667 m2 had the best performance. When copolymer amount was 1-4 kg per 667 m2, the plant root weight and shoot fresh weight showed better with the increasing of copolymer, but the effect of 5 kg per 667 m2 was not as good as 3 kg and 4 kg treatment. The water utilization efficiency of the treatment of 1~5 kg copolymer per 667 m2 were 14.95%, 27.80%, 35.22%, 43.52%,18.05% higher than that of the control, respectively.