Effects of coronatine on lodging resistance and yield of maize

A field experiment using maize varieties Xianyu335 and Zhengdan958 was conducted to study the effects of spraying coronatine (COR) with different concentrations (0, 0.01, 0.1, 1 and 10 μmol/L) at V8 stage on maize yield and lodging resistance. The results showed that the plant height and ear height of Xianyu 335 treated with 10 μmol/L COR were decreased by 7.0% and 19.9%, respectively. And those of Zhengdan 958 were decreased by 20.8% and 18.2%, respectively. And the leaves area per plant, the breaking resistance, the length of the 8^th-14^th internodes and the maximum diameter of the 8^th-14^th internodes were significant different from the control. While the plant height, the ear height, the leaves area per plant, and the length of the 8th-14th internodes were decreased. And the maximum diameter and breaking resistance of the 8^th-14^th internodes were increased with the increase of the concentration of COR. Grain yield, ears per hm², grain numbers per ear, and thousand grain weight of those two maize varieties treated with 1 μmol/L COR were increased compared with the control. The grain yield of Xianyu 335 increased by 9.9% compared with the control, and Zhengdan 958 increased by 4.3% compared with the control. In summary, COR could increase the lodging resistance of maize. The optimal COR concentration for Xianyu335 to increase lodging resistance was 10 μmol/L and that for Zhengdan958 was 1 μmol/L, indicating that different maize varieties have different sensitivity levels to COR.