Study On Preparation And Properties Of Chitosan-based Foliar Antitranspirant

In the northwest China, the action time of pestcide is short and its efficacy is low,leading to serious insect pests, causing huge economic losses. In this paper, it was worked that to prepare a kind of foliar antitranspiratant to delay the leaf transpiration rate effectively, inhibite water evaporation and prolong the action time of the liquid greatly. It may enhance the single fertilizer effect and improve the pest problem fundamentally using the conbination of antitranspiratant and pestcide.In this study, by using natural biodegradable chitosan as raw material, antitranspiratant RA and RG were prepared and tested by various mehtods, such as different blade effects test, water retention performance test, environmental stability testing, chlorophyll fluorescence analysis. The main results are as follows:(1) Photosynthesis and respiration of plants was influenced hardly by antitranspiratant RA, which was suitable for all growth stages. The relative evaporation rate of RA on Chinese wolfberry tested was 19.91 % of CK, which was effectively worked on reducing the evaporation rate of water. It was indicated that RA water retention capacity was about 1.5 times of CK and the evaporation rate was half-time of CK, with inhibiting water evaporation rate up to 48.7%. Besides that, relative evaporation rate of RA was lower with temperature or wind speed increasing, and it was approximately stable under various conditions of salinity, pH and calcium concentration. Moreover, it was good for compatibility of RA and pesticide that the compound of which didn't affect their owe effects respectively.(2) Antitranspiratant RG was divided into two groups, including RGC based on chitosan and RGCS based on carboxymethyl chitosan. The initial gel temperature of antitranspiratant RGC was 32?, and RGC had no effect on physiological behavior of plants, and was suitable for all growth stages. In water retention performance test, it was resulted that water retention capacity of RGC was about 2.41 times of CK and the evaporation rate was 36% of CK, with inhibiting water evaporation rate up to more than 63%. Water retentiong capacity of RGC was related to the environment, as the temperature and the wind speed was higher, the action effect of RGC was greater. The initial gel temperature of antitranspiratant RGCS with carboxymethyl substitution degree of 0.11 was 31?. It was indicated that the higher the temperature was, the shorter gel time was, with time temperature equivalence of sol-gel transition. Same as RGC, RGCS was suitable for all growth stages. It was resulted that water retention capacity of RGCS was about 2.46 times of CK in water retention performance test, and the evaporation rate was 34% of CK,with inhibiting water evaporation rate up to more than 65%. The temperature and the wind speed was higher, the action effect of RGC was greater.