The Effects Of Different Water Treatments On Physical Growth And Water Consumption Of Winter Oilseed Rape Under Film Mulching

Oilseed rape is one of the important oil crops in the world, in order to solve the problemsof low temperature and little rainfall which limit the growth and development of winteroilseed rape in the arid and semi-arid regions of northwest China, plot experiment and potexperiment were confined to evaluate the effects of different water treatments on physicalgrowth and water consumption of winter oilseed rape in seedling stage and stem elongatingstage under film mulching. Water treatments involves soil moisture maintained among70%~80%of field capacity in the whole growth stage (QG), soil moisture maintained among60%~70%of field capacity in the whole growth stage (QZ), soil moisture maintained among50%~60%of field capacity in the whole growth stage (QD), soil moisture maintained among60%~70%of field capacity in returning green stage (FZ), soil moisture maintained among50%~60%of field capacity in returning green stage (FD). Soil moisture was maintainedamong70%~80%of field capacity in other growth stage of FZ and FD. The treatments ofpot experiment were divided into under buried environment and normal environment. Theresults show at the end of stem elongating stage:1. It has significant impacts on the growth indexes of winter oilseed rape among differentwater treatments（1）Plant heightNo matter it was pot experiment or plot experiment, plant height of FZ almost equals tothat of QG, and the plant height values of the two treatments are significant greater than othertreatments. As to pot experiment, compared to MQZ, the plant height of MQG and MFZ hasincreased11.76%and12.74%, respectively; and compared to MQD, the plant height of MQGand MFZ has increased15.38%and5.42%, respectively; and the plant height of LQG andLFZ compared to that of LQZ, has increased23.10%and6.82%, respectively; and the plantheight of LQG and LFZ compared to that of LQZ, has increased15.38%and5.42%,respectively. As to plot experiment, the plant height of QG and FZ compared to that of QZ,has increased6.38%and4.47%, respectively; and the plant height of QG and FD compared tothat of QD, has increased8.53%and4.88%, respectively.（2）Stem diameterNo matter it was pot experiment or plot experiment, stem diameter of FZ almost equivalents to that of QG, and the stem diameter values of the two treatments are significantgreater than other treatments. As to pot experiment, compared to MQZ, the stem diameter ofMQG and MFZ has increased10.02%and7.07%, respectively; and compared to MQD, thestem diameter of MQG and MFZ has increased21.80%and14.47%, respectively; and thestem diameter of LQG and LFZ compared to that of LQZ, has increased6.93%and5.17%,respectively; and the stem diameter of LQG and LFZ compared to that of LQZ, has increased18.54%and14.66%, respectively. As to plot experiment, the stem diameter of QG and FZcompared to that of QZ, has increased9.85%and8.31%, respectively; and the stem diameterof QG and FD compared to that of QD, has increased15.46%and9.70%, respectively.（3）Leaf areaThere was no significant difference among three treatments of QG, FZ and FD.Compared to QZ, the leaf area of QG and FZ has increased8.98%and26.77%, respectively;and the leaf area of QG and FD compared to that of QD, has increased30.01%and34.47%,respectively; and the leaf area of QZ has increased19.30%compared to that of QD.（4）Above-ground dry matter accumulationThe above-ground dry matter accumulation of all the treatments were QG（150.78g/plant）＞FZ(137.85g/plant)＞FD(123.03g/plant)＞QZ(116.93g/plant)＞QD(109.76g/plant) successively.2. There were significant effects on the physiological indexes of winter oilseed rapeamong different water treatmentsNo matter it was pot experiment or plot experiment, after rewatering, the content ofchlorophyll and photosynthetic rate of FZ are significant greater than other treatments, and thecontent of chlorophyll and photosynthetic rate of FD are a little less than those of QG.3. Water consumptionThe sum of the water consumption in seedling stage, returning green stage and stemelongating stage were:Pot experiment: MQG（15.655kg）＞MFZ（15.324kg）＞MFD（14.939kg）＞MQZ（13.661kg）＞MQD（13.136kg）; LQG（16.302kg）＞LFZ（15.955kg）＞LFD（15.392kg）＞LQZ（14.176kg）＞LQD（13.619kg）;Plot experiment: QG（251.17mm）＞FZ（246.24mm）＞FD（235.84mm）＞QZ（211.65mm）＞QD（195.09mm）.No matter it was pot experiment or plot experiment, the sum of water consumption inthe three growth stage of QG is larger than other treatment, the water consumption of FZ islarger than that of FD, And the water consumption of the two treatments FZ and FD is larger than that of QZ and QD.