Effects of Soil Water Potential on Panicle Characters and Yield of Rice in Cold Region

A pot culture experiment was conducted to study the effects of soil water potentials at ranges from-30 to(-35) kPa,-60 to-65 kPa and 0 kPa(check) during different developmental stages on panicle characters and grain yield by(using) two rice varieties Shangyu 397 and Suijing 3 as materials.The treatments at panicle-formation period had the greatest effect on panicle characters and the panicle number under the treatments was significantly more than that in control.The panicle length,numbers of panicle nodes and branches under the treatments during panicle-formation period were also significantly more than those under the control and the treatments during the other periods.However,the difference of panicle number between two soil water potentials was not significant among all the treatments at each treatment stage.The grain yields under the treatments during panicle-formation period were significantly lower than that in control.Obvious effects of soil water potential on grain yields under the treatments at the tillering stage and one to ten days after heading were founded.Panicle length,numbers of panicle nodes and branches were significantly positively correlated with the yield of the middle-position grain and inferior grain.