关键词: 多效唑, 谷子, 茎秆强度, 抗倒伏

Abstract: In order to study the effects of paclobutrazol on stalk traits and panicle neck lodging resistance of foxtail millet, this paper used a randomized block design, 300 mg·L^-1  paclobutrazol were sprayed on foxtail millet leaf at the stage before jointing (A1), jointing stage (A2) and booting stage (A3), which water was used as control (CK). Stalk characters, lodging index, panicle parameters and yield of millet were measured. The results were as followed. ① Compared with CK, the growth and development of millet plants were significantly inhibited. The earlier spraying period was, the more obvious inhibition effect was, and the lower plant height was. ② The plant heights of the two varieties were the minimum in A1 treatment, and the ratio between height of gravitational center and plant height had similar changing trend. The stem diameter of basal internode was increased and reached the maximum value in A1 treatment. With the advance of paclobutrazol spraying period, the decreasing range of internode length was smaller, and the internode diameter was gradually increased with the decrease of internode length, and the stalk plumpness was significantly improved. ③ With the advance of paclobutrazol spraying period, the bending moment and lodging index were increased gradually, the bending force was decreased, and lodging resistance was gradually decreased. All of them were best in A1 treatment. ④ In terms of panicle neck, the water content and bending moment of Nongda 8 had been obviously changed. Among them, the bending moment of panicle neck was the smallest in A1 treatment, while the water content of panicle neck was the lowest in A2 treatment. However, there was no significant change  other indexes except the bending moment of panicle neck of Zhangza 10. Among them, the bending moment of panicle neck reached the minimum in A1 treatment. ⑤ The key components affecting the yield of millet were panicle weight and grain weight of panicle. In A2 treatment, yield was increased significantly. Compared with CK, the yields of Nongda 8 and Zhangza 10 were increased 7.10% and 8.29% higher, respectively. Therefore, the spraying of 300 mg·L^-1  paclobutrazol at the jointing stage could improve the stalk plumpness and enhance the lodging resistance. The effect of increasing yield was the best.

Key words: foxtail millet, paclobutrazol, stalk strength, lodging resistance