Effects Of Water And Light Treatment On Water Consumption And Growth Phsiological Characteristics Of Summer Maize

Light environment and soil water content arc important external factors affecting crop growing development,and play a decisive role in crops.In this study,natural light was controlled by white gauze and black shading net,natural light was used as control(LO),three light control gradients of 10%(L1),20%(1,2)and 30%(L3)were set at the late seedling stage,at the same time,three water control gradients of conventional irrigation amount(WO),70%W0(W1)and 50%W0(W2)were set under L0,L1 and L2 treatments at the end of jointing.Taking summer maize as the research object,the effects of light and irrigation on various inndicators ol summer maize were explored.The main results of the study are as follows:(1)The diurnal variation of canopy and soil temperature in summer maize showed a trend of "first increase and then decrease".After light control and water control,the canopy temperature decreased with the increase of the control luminosity and the decrease of the irrigation amount,the temperature in the canopy showed:upper layer>middle layer>lower layer,the greater the control luminosity,the smaller the temperature difference of each layer.The canopy humidity is negatively correlated with temperature,and the lowest humidity has a delay phenomenon with the increase of the control luminosity.The soil temperature of the light control treatment showed:L0W0>L1W0>L2W0>L3W0,and the higlhest value of soil temperature gradually lagged with the increase of he control luminosity and soil depth.(2)The diurnal variation of evaporation between the trees in summer maize showed a trend of "first increase and then dccrease",and reaching the maximum at 12:00-14:00.The day evaporation intensity showed a decreasing trend with time.The total water consumption and evaporation between the trees decreased with the increase or the control luminosity and the decrease of the irrigation amount,the effcct of light control and water control on the water consumption in each growth period were the same as that in the whole growth period.The cflcctive rainfall and irrigation accounted for more than 81.2%of the total water consumption,and the water consumption modulus was the largest during jointing and milking.(3)The higher the control luminosity,the smaller the chlorophyll a and b,the net photosynthetic rate,the stomatal conductance and the intercellular CO2 concentration were in the leaves of the light-controlling treatment of summer maize,the each indicator and each layer in the jointing stage and the flowering and silking stage showed:Upper layer>lower layer,middle layer>upper layer>lower layer.The chlorophyll b and photosynthetic indexes were significantly different between LOWO and L3W0 treatments(p<0.05),while chlorophyll a was significantly different in each treatment layer.The growth period of summer maize was prolonged by controlling light and water.The greater the control luminosity and the smaller the irrigation amount,the smaller the plant height,leaf area index(LAI)and dry matter mass and the average rate of accumulation,there were differences in the distribution of dry matter quality under each treatment.(4)The content of starch and crude fat,yield,ear length,ear diameter,ear grain number,row grain number,ear grain weight and thousand grain weight of summer maize decreased with the increase of control luminosity and the decrease of irrigation water,while the length of bare tip and water productivity increased.The content of crude protein increased with the increase of control luminosity and irrigation water.The yield difference between LOWO and L3W0 treatment was significant.The order of influence of each component on yield was as follows:ear grain weight,ear grain number,ear length,row grain number,thousand grain weight,ear diameter,he length of bare tip.(5)L2W0 treatment has good water-saving effect,no significant difference in yield and high water productivity,so it meets the requirements.Compared with the LOWO treatment,the total water consumption and yield of L2W0 treatment were reduced by 16.5%and 12.3%,respectively.In this paper,there is a good correlation between the fitting function of the indicators and control luminosity,and the value of each index can be predicted within 30%of controlled luminosity.