Study On The Water Use Rules Of Peanuts Under Irrigation Amount And Staged Water Deficiency And Moisturizing Irrigation

In this study,Huayu 25?HY25?was used as the experimental material,the effects of water deficit on the growth and physiological characteristics of peanuts under different irrigation quota and different growth stages were studied by using the combination method of pooling and potting cultures.The changes of physiological characteristics,photosynthetic characteristics,water use efficiency?WUE?,yield and quality of peanuts under different irrigation amounts,water shortage at different growth stages and phased drought conditions were revealed.The water absorption and utilization rules of peanut and the response characteristics of water were initially established,which provided theoretical guidance for the drought resistance and water saving cultivation of peanuts in agricultural production.1.The main stem height and lateral branch length treated with 9000 m³·hm^-2 irrigation in the whole growth period of peanuts were well fitted with Logistic growth curve regression equation,the correlation coefficient R² was higher than 0.98,the maximum growth rate V_m,dry matter accumulation,biological yield WUE,leaf WUE and economic yield WUE were the highest.The contents of antioxidant enzymes in the leaves and the contents of the osmotic adjustment substances in the membrane system under different treatments were all decreased with the increase of the irrigation amount,each index presented the smallest under the irrigation quota of 9000 m³·hm^-2?T4?.The highest economic yield was obtained under the irrigation quota of 9000 m³·hm^-2?T4?,yields under the irrigation quota of 4500 m³·hm^-2?T1?,6000m³·hm^-2?T2?,7500 m³·hm^-2?T3?and 10500 m³·hm^-2?T5?were decreased 9.5%,31.5%,18.1%and 27.2%,respectively compared with 9000 m³·hm^-2?T4?.2.The growth process of peanuts was all delayed under different conditions of water shortage in the growth stages,the growth rate and dry matter accumulation rate of the peanuts were slowed down.Of which,drought in the flower-pegging stage?D3?was the most obvious,and the high level of biological yield WUE could be maintained with this treatment under drought condition,and the water compensation effect was not obvious after drought.Under water shortage,sucrose synthase?SS?,sucrose phosphate synthase?SPS?and glutamine?GLS?activities in peanut leaves and pods increased significantly,while glutamate synthase?GOGAT?activity decreased.In the indexes of economic yield,reduction of output was the most serious under drought in fruiting period?D4?,the economic output WUE presented as the lowest under drought in the flower-pegging stage?D3?,and the economic yield WUE was D0>D2>D1>D4>D3.According to the comprehensive indicators,the mild drought in seedling stage was beneficial to improve the water use efficiency.The most sensitive water requirement was in the flower-pegging stage,which was the threshold of the water demanding.In the podding period,the water demand was the biggest,and the drought would cause the most serious reduction of output.The effect of reduction was the smallest in mature stage,but it had a great influence on the formation and accumulation of crude fat in seed kernel.3.The growth rates of main stem height,lateral branch length and dry matter accumulation achieved the highest under water supplementary?W20?during 20-40 d of blossom,and were all higher than those under other treatments,the net photosynthetic increased rate was the biggest,transpiration increased rate was the smallest.The SS,SPS and GLS viabilities of leaves and pods with water supplementary after different drought treatments were drought and water shortage in the whole growth period?W?>water supplementary during 60-80 d of blossom?W60?>water supplementary during 40-60 d of blossom?W40?>water supplementary during 0-20 d of blossom?W0?>water supplementary during 20-40 d of blossom?W20?>control water supplementary in the whole growth period?CK?,the activity of GOGAT presented the opposite,which was CK>W20>W0>W40>W60>W.In each treatment,in addition to CK,the leaf level WUE,biological yield WUE and economic yield WUE were higher under W20treatment,20-40 d at the first blossom was the stage that required the most water demand efficiency.