Impact of Different Irrigation Methods on Resistance of Rice Against Bending and Breaking

GUO Xiangping; HUANG Shuangshuang; WANG Zhenchang; WANG Fu; CHEN Bin

doi:10.13522/j.cnki.ggps.2017.05.001

Abstract：The impact of four irrigation methods-deep flooding irrigation (FI),frequent-shallow irrigation (DSI),controlled irrigation (CI) and rain-capture and controlled irrigation (RC-CI)-on resistance of rice against bending and breaking was investigated experimentally in this paper.The results showed that in comparison with the traditional flooding irrigation (CK),the two water-saving irrigation methods (CI and RC-CI) (①)significantly increased (P＜0.05)the diameter,wall thickness and cross section of the rice stem,(②)increased the plumpness and decreased the length of the first and second intermodal stems.Compared with FI,CI and RC-CI increased the breaking-resistance (BR) by 32.58％ and 43.69％ respectively,and the bending moment (BM) by 8.04％ and 9.64％ respectively,leading to an increase in lodging index LI (LI=BM/BR) by 18.60％ and 23.60％ respectively.Compared with FSI,BR under CI and RC-CI increased by13.48％ and 22.99％ respectively,whereas their associated BM increased only by 0.42％ and 1.91％ respectively,leading to a decease in LI by 14.54％ and 17.08％ respectively.The two water-saving irrigation methods increased the accumulation of dry matter androot-shoot ratio in comparison with CK.Compared with FI,CI and RC-CI increased the ratio of stem-sheath dry matter to aboveground dry matter by 8.16％ and 9.00％ respectively,whereas decreased the ratio of panicle dry matter to aboveground dry matter by 4.03％ and 4.27％ respectively.Compared with FSI,CI and RC-CI increased the ratio of stem-sheath dry matter to above-ground dry matter by 2.56％ and 3.32％,while decreased the ratio of panicle dry matter to above-ground dry matter by 2.29％ and 2.53％,respectively.The root-shoot ratio and the ratio of stemsheath dry matter to above-ground dry materswere negatively correlated with LI (P＜ 0.01),while the ratio of panicle dry matter to above-ground dry matter was positively correlated with LI (P＜0.05).BR and BM under RC-CI increased slightly in comparison with those under CI,and there was no significant difference in LI between the two irrigation methods (P＞ 0.05).