Study On Photodegradation Of Chlorothalonil In Cabbage And Extract Flowed Through The Pakchoi

As a high-efficiency,low-toxic,broad-spectrum fungicide,chlorothalonil is widely used in agricultural production and causes a series of environmental problems.Proanthocyanidins promote photodegradation of chlorothalonil in water and inhibit the formation of 4-hydroxy chlorothalonil.However,proanthocyanidins are widely present in plants,so it is thought that the proanthocyanidins of the plant itself can promote the degradation of chlorothalonil,and whether it can inhibit the formation of 4-hydroxy chlorothalonil.This paper mainly studies the effects of the plant's own proanthocyanidins on the degradation of chlorothalonil.The plant tissue extract was obtained by water extraction method and the photodegradation of chlorothalonil in plant extracts was investigated.The photodegradation of chlorothalonil on the surface of common cabbage and purple cabbage leaves with different proanthocyanidin contents was studied.It provides some references for the safe use of chlorothalonil.The experimental results are summarized as follows:1.Under the illumination of xenon lamp,the extracts of common cabbage and purple cabbage extracted by water extraction can promote the degradation of chlorothalonil.The extract of cabbage leaves was added to the aqueous solution containing 1 mg/L of chlorothalonil.After 1 h of illumination,the removal rate of chlorothalonil reached about 40%.There was no significant difference in the degradation of chlorothalonil between two cabbage leaf extracts,but the leaf extracts of different layers of cabbage had significant differences in photodegradation.Adding the outermost common cabbage leaf juice,the removal rate of chlorothalonil was about 50%after 1 h of light,and the removal rate of chlorothalonil was 70%after adding the innermost layer of juice for 1 h;the addition of purple cabbage leaf extract also With the same trend,the removal rate from the outermost layer increased from 58%to 72%of the innermost layer after 1 h of illumination.The effects of the two kinds of cabbage from the outer leaf extract to the innermost leaf extract on the degradation of chlorothalonil were enhanced.2.The extracts from different parts of the plant have different ability to promote the degradation of chlorothalonil.The five different extracts of flowers,flower buds,leaves,petioles and stems are selected.After 1 h of illumination,the solution contains 1 mg/L of chlorothalonil.The removal rates of chlorothalonil were 82%,84%,60%,28%,and 40%,respectively.The effect is as follows:flower buds>leaves>stems>petiole.3.The extracts of different color flowers promoted the degradation ability of white fungus.The degradation rate of chlorothalonil was about 78%after 1 h of xenon lamp illumination.4.Under UV light,the photodegradation rate of chlorothalonil on the surface of two cabbage leaves was slower,but the degradation rate of chlorothalonil was significantly accelerated after the wound treatment of cabbage leaves.5.The addition of proanthocyanidins on the surface of cabbage leaves could not promote the photodegradation of chlorothalonil,but inhibited the photolysis of chlorothalonil,and had no effect on the photodegradation of chlorothalonil after moisturizing the leaves.