Effects Of Shading And Fogging On Growth And Physiological Characteristics Of Ginger

In order to innovate the technique model of ginger cultivation,the effects of four treatments,which is shading and fogging?S+F?,fogging but no shading?-S+F?,shading but no fogging?S-F?and no shading and no fogging?-S-F?on ginger field,and the growth of ginger and some physiological characteristics of ginger field were studied with'Laiwu'ginger to evaluate the interactive effects of shading?Shading/S?and fogging?Fogging/F?.The main results are as follows:1.Fogging treatment can significantly reduce the canopy temperature of ginger plants by increasing air humidity.The average temperature of S+F,-S+F,S-F and-S-F were 27.6?,29.3?,30.4?and 33.2?,respectively,in July 12,2016,while the soil moisture content in the ginger field was higher,in July 28th,compared with-S-F,the treatments of S+F and S-F are on an increase rate of 12.21%and 9.13%respectively.2.Although aerial parts of ginger via fogging cultivation was smaller than that via shading cultivation,rhizomes of ginger were larger and the economic coefficient was higher.The-S+F was the highest with a field of 2688.68 kg/667m²,and the S+F was 2640.65 kg/667m²,which was 1.7%and 0.7%increase compared to shading cultivation?S-F?,and a rate of 31.3%and28.9%increase compared to the no shading and no fogging?-S-F?respectively.3.The chlorophyll content in ginger leaves treated by S+F and S-F was significantly higher than that in-S+F and-S-F treatments,but the content of carotenoid in leaves was significantly lower than that in-S+F and-S-F treatments.In sunny days,10:00-16:00 is the high temperature,strong light and low humidity period,during which period the fogging treatment could significantly increase Fv/Fm,?PS?,qP,Pn and gs in ginger leaves,also decreased the photosynthetic midday depression.The photosynthetic rate of leaves appeared at the first peak at 11:00,the S+F,-S+F,S-F and-S-F processing were 12.10,13.23,11.43 and 9.23?mol·m^-2·s^-1 respectively.When the valley value was at 13:00,the photosynthetic rate of S+F and-S+F were 75.04%,and 90.84%higher than-S-F.The diurnal variation curve of transpiration rate is a single peak curve,the peak appeared at 13:00,and the leaf WUE showed two peaks in one day,the peak appeared at 11:00 and 15:00,the largest WUE was got by-S+F,and followed were the S+F and S-F,while-S-F was the smallest.4.Under natural light conditions,the activities of NR,GS and GOGAT in ginger leaves and roots treated with-S+F and-S-F were significantly higher than those in S+F and S-F treatments.When treated at 56 d,the NR activity of-S+F treated leaves increased by 12.13%,18.71%and 4.52%respectively than that of S+F,S-F and-S-F treatments.The content of nitrate nitrogen and soluble protein in ginger leaves and roots were higher than that of shading treatment under natural light,and the-S+F treatment was significantly higher than that of other treatments,for the treatment of 28 d,the NO₃^-content in root system respectively 94,115,99and 111?g·g^-1 in S+F,-S+F,S-F and-S-F treatment,while the free amino acid and ammonium nitrogen content were higher in light shading treatment.5.The activity of SOD,POD,CAT and MDA content of ginger leaf and root were significantly increased under high temperature and strong light environment.The ROS content in the ginger plant was reduced by adding light shading or fogging treatment.For example,when dealed with for 56 d,the H₂O₂ contents of 4 treatments were 0.23,0.27,0.33 and 0.36?mol·g^-1 respectively.The largest activity of antioxidant enzyme was got by-S-F,and followed by S-F,and S+F and-S+F was smaller.when dealed with for 56 d,the CAT activity in the S+F,-S+F,S-F and-S-F treatments were 9.86,11.14,13.86 and 14.16 U g^-1 respectively.6.In the process of soil water control,the decrease of Fv/Fm,?PS?,qP,net photosynthetic rate and stomatal conductance of ginger leaf slices was smaller,such as when dealed with for 9d,the photosynthetic rate of S+F,-S+F,S-F and-S-F treatments decreased by 41.55%,73.32%,47.42%and 83.47%respectively when compared with the of 3 d`s treatment,and as the stress aggravated,the diurnal variation of photosynthetic rate also showed different trends.The photosynthetic rate of S+F,-S+F and S-F treatments leaves appeared at the first peak at 11:00,while the-S-F treatment appeared at 9:00 and the photosynthetic rate was smaller,only 8.07?mol·m^-2·s^-1,indicating that shading or fogging treatment could alleviate the damages of soil drought stress to plants.