Effects Of Mulching On The Photosynthetic Characteristics And Fruit Quality Of Facility Grapes In Rainy Seasons And Dry Seasons

Diffuse light is beneficial to the growth and development of plants,it can improve the utilization rate of light energy,adjust the light environment,it is known as another kind of"fertilizer"of plants.In the middle and lower reaches of the Yangtze River in summer,there are continuous rainy weather and drought weather every year.In rainy weather,the diffuse radiation is more than drought weather but the light is insufficient and the light quality is poor,which easily leads to barren branches and underdevelopment of plants.Drought weather has more direct light but less diffuse light with high temperature,the situation is easy to cause plant heat damage.In this study,the perennial facility grape was taken as the research object,aiming at the problem of insufficient utilization of diffuse radiation in the actual production,the method of adjusting the diffuse radiation proportion is studied,in order to make a contribution to the actual production.This research adopts the laying diffuse film and reflective film at the same time,using the combination of the two film to adjust the proportion of diffuse light,testing set up five groups of different layers of the diffuse film and reflective film,and lay no film in CK group for comparison,in the process of determination of grapes radiation intensity under rainy weather,drought weather,including direct radiation and diffuse radiation intensity;At the same time,the photosynthetic characteristics of grape leaves in rainy weather and drought weather are measured,and the quality of grape fruits is also measured.The main research contents and experimental results of this study are as follows:(1)Using a handheld device measuring diffuse radiation intensity,the handheld device including shading ball,stents,radiation sensor and data collector and so on several parts,it is different from the existing block halo method and block plate method,the handheld device is small and light,easy to move,and it can according to the demand of mobile location anytime and anywhere;(2)Comparing with CK group,covering the diffuse film and reflective film can effectively increase the diffuse light proportion in rainy weather and drought weather,but the total radiation intensity will decrease;(3)Covering diffuse film and reflective film in drought disaster weather significantly increased the photosynthetic capacity of the plant,plant under drought disaster weather net photosynthetic rate,stomatal conductance,intercellular CO₂concentration,transpiration rate,higher than that of CK group F_v/F_m,F_v/F₀,ABS/RC,PI_absand leaf chlorophyll content,higher than that of CK group T5 group processing under the best of every index,The net photosynthetic rate,stomatal conductance,intercellular CO₂concentration and transpiration rate of all treatments had no significant changes under cloudy and rainy weather;(4)Covering diffuse film and reflective film in rainy weather and drought weather is positive for the quality of the grapes,especially after continuous rainy weather and drought weather,grape fruit fruit diameter,weight,content of soluble sugar content,organic acid,sugar,acid,ascorbic acid content,protein content and anthocyanin content are higher than that of CK group,among which the fruits of group T5(covering 2 layers of diffuse film and 1 layer of reflective film)has the best quality;(5)Through fuzzy comprehensive evaluation of grape fruit quality indicators,it is found that the best treatment for grape fruit quality was group T5,that is the treatment of two layers of diffuse film and one layer of reflective film.This study proved that the method of laying diffuse film and reflective film at the same time can effectively improve the photosynthetic reaction rate,dry matter distribution ability,improve grape fruit quality,and improve the efficiency of grape production.