Research On Drought Resistance And Yield Stablization Technology Of Double Cropping Rice

Drought is becoming one of the most of key abstacle in rice producation. To exprolation the dronght-resistand and yield stabilization in double cropping rice, field experimnets with Lingliangyou211was carried out to test the effect of different water storage period and storage depth one growth and yield formation in early season rice, and with Xiangfengyou9to test the water-saving effect of transpiration inhibitors on double cropping later rice. The results showed that:1. The depth of water has a strong impact on tillering:Deep water at the early stage would reduced the number of tillers, inhititored the grwoth of rice at later growth stage concountuntly. However, shallow water persecution has little stress on tillering. The Max tillers was rechieved20and19per hill.2. Different water depth has effect on SPAD value. At max tillering stage, the SPAD value under deep water trteatment was42.3, higher than shollow water, was38.6. At booting stage, the SPAD value of shollow water higher than deep warer trmeatment, which meaned that rice is very sensitive to water stress, tillering stage is a key period of deciding the leaf chlorophyll level.3. There is an obvious influence on the content of chlorophyll by spraying growth regulator and leaf fertilizer.The chlorophyll level of testing rice sprayed transpiration inhibitors of diethyl aminoethyl hexanoate and potassium dihydrogen phosphate was22μmol/m2.s, was higher than that sprayed by fulvic acid and potassium chloride.4. Water storage in seedling establishment and tillering period would reduce leaf area, were856.76and931.58cm2per hill, while it’s adverse in booting stage. After full heading stage, rice leaf area declined. Booting stage was the most sensitive period of rice to water condition, also an important period that affect the leaf area. Under different processing conditions, leaf area of testing varieties gradually increased with the process of birth, which meet the maximum of increase range from tillering stage to booting stage, milk-ripe stage is the highest. Application of transpiration inhibitors can increase the rice leaf area.5. Early water storage makes the transportation of dry matter to stem sheath was more than that to blade,which leads to decrease of leaf area. At booting stage,water storage reduces the accumulation of dry matter of rice on the ground. Into full heading stage, dry matter in leaf begins to move to spike,but the speed of moving in water storage processing is slower. At milk stage, the weitht of per panicle was28.7g, higher than that of nonmal water management of26.4g.6. Root activity and proline content of tested varieties show unimodal curve from tillering stage to milk ripe stage under different processing, the peak was achiefed at the booting stage. Different reagents have different impact on root vigor. The root vigor of sprading diethyl aminoethyl hexanoate and potassium dihydrogen phosphate was the highest through all stage.7. Different transpritor hibtors could changed the photosynthesis, also with the content. The photosynthesis sprading diethyl aminoethyl hexanoate and potassium dihydrogen phosphate was19.14μmol/m2.s,17.2%higher than that CK. The photosynthesis of sprading KCL、transpiration inhibitors and fulvic acid were18.61、17.93and17.32, and14.0%、9.8%,6.1%higher than CK.8. The productive panicle number of rice will be reduced under water stress in tillering stage, while has no effect by drought in booting stage and full-heading stage. Weight of rice kernels will be reduced by drought in tillering stage, but it’s advantageous to the increase of it by mild drought in later tillering stage, also in booting stage by water storage. Tillering and booting stage are two of the most important periods effecting yield in rice growth, suffering from mild drought is beneficial to improve the yield in later tillering stage.Water storage increased production in both seedling establishment period and tillering, while adverse in booting stage, but little influence by shallow water storage. Compared with conventional water management, the main cause of yield reduction in booting stage is a decline in real grain numbers per spike, and seed setting rate. Different transpiration inhibitors or same transpiration inhibitor different concentration also have an impact on yield indicators of late rice.