Evaluation And Classification Of Low Fertilizer Tolerance Ability Of Main Rice Varieties In Guangxi

In order to evaluate the low fertilizer tolerance of main rice varieties in Guangxi,72 rice varieties were collected from different rice planting areas in Guangxi.After sowing,48 early rice and 60 late rice varieties were selected for field experiments according to the growth of seedlings and the size of the experimental field.A total of four treatments(1/3 normal nitrogen,no phosphate,no potassium,and normal fertilizer)were designed.Yield was harvested at maturity stage and panicle number structure was investigated.The relative yield was used as the main evaluation index to evaluate the low fertilizer tolerance of rice varieties.The results showed that the low nutrient tolerance of early and late rice varieties could be divided into several groups.Among of them,20 early rice varieties with low nitrogen tolerance were more than 0.92;17 varieties with low phosphorus tolerance wasmore than 0.93;and 25 varieties with low potassium tolerance was more than 0.93.The results showed that Guangliangyou 1598,Guiliangyou 2,Teyou 5,Teyou 582,Guifeng 2,Teyou 3813,Tyou 6135,Keliangyou 889,Zhongguangxiang 1 and Aviation Asia Jinzhan was tolerant to low nitrogen,phosphorus and potassium at the same time.Among the tested late rice varieties,26 varieties were tolerant to low nitrogen and their relative yield was more than 0.90;7 varieties were tolerant to low phosphorus and their yield was more than 0.91;32 varieties were tolerant to low potassium and their relative yield was more than 0.90.Among the late rice varieties,Fengliangyou 4,Zhongyanyou 519,Yexiangyou 688,Guifeng 2,Teyou 582 and Yexiangyou 2 was tolerant to low nitrogen,phosphorus and potassium at the same time.There was no significant difference in yield among different classifications of rice cultivars under normal treatment.The results showed that the tolerance of rice to low fertilizer was not affected by its own yield.However,with the increase of low fertilizer tolerance,the normal treatment yield of the tested late rice varieties decreased,although there was no significant difference among different varieties.Low fertilizer treatment significantly reduced grain yield and above ground dry matter yield of rice.Among them,low phosphorus treatment had the greatest impact,followed by low nitrogen and low potassium respectively.Low fertilizer treatment significantly affected the population quality of rice,and there were some differences between early rice and late rice.In the early rice experiment,low nitrogen and phosphorus treatment affected the effective panicle number,panicle weight and yield of rice,while low potassium affected the panicle weight,but had little effect on the effective panicle number.Low fertilizer stress in late rice reduced the number of effective panicles.Low nitrogen and phosphorus had little effect on the weight per panicle of rice.However,low potassium treatment increased the weight of single panicle.Low nitrogen and phosphorus treatment had little effect on the harvest index,but low potassium treatment could improve the harvest index in late rice.