Synergism Mechanism Of Organic Silicon And Xanthan Gum On Fungicide

Wheat scab is a typical disease of climate, whose occurrence is closely related with the weather condition of warm and rain. Rainfall in the growing season often caused us can not spray control chemicals properly, which will cause severe occurrence of this disease. Addtion of additives can reduce the surface tension of chemicals, increase the adhesion with the crops and enhance the capacity of resistance to rain erosion, which will improve the control effect with less chemical. In this experiment, we tested wheat as plant, triadimefon and carbendazim as control agents, studied synergies of four additives——organic silicon, XG-5, XG-7 and XG-9, tested effect on the deposit of chemicals of different additives by using pesticide residue analysis and selected representative additives conducive to deposition to do rain erosion test, verified the effect of additives'application in the field efficacy trials, in order to find the best variety and concentration of additive that can increase the deposit of chemicals.1. We used pesticide residue detection method to determine the deposit amount in wheat leaves of triadimefon and carbendazim after adding additives. The results showed that:①Residue of triadimefon:triadimefon+ organic silicon> triadimefon+ XG-9> triadimefon+ XG-5> triadimefon+ XG-7> triadimefon.②Application of wetting agent organic silicon increased the deposit amount of carbenazim by 29.1%, application of thickener XG-5, XG-7 and XG-9 increased the deposit amount of carbenazim by 13.0%,13.7% and 12.6% respectively.2. Representative variety organic silicon and XG-5 were selected to do screening test of concentration, different concentrations of organic silicon and XG-5 were added into triadimefon and carbendazim, the concentrations of organic silicon were 0.05ml/l,0.10 ml/l, 0.15 ml/l and 0.20ml/l, the concentrations of XG-5 were 1ml/l,2 ml/l,3ml/l and 4ml/l. The residue results showed that deposit of triadimefon increased with the increasing concentration of additives gradually with concentration of organic silicon between 0.05ml/l to 0.15ml/l, which decreased when the concentration was more than 0.15ml/l, The concentration range of organic silicon recommended by author was 0.05ml/l～0.15ml/l. Deposit of carbendazim was highest with the concentration of 0.05ml/l, which dropped when the concentration of organic silicon was more than 0.10 ml/l. The concentration range of organic silicon recommended by author was 0.05ml/l～0.10ml/l. The best concentration range of XG-5 was 1ml/l～2ml/l.3. Deposit of triadimefon and carbendazim under conditions of different rainfall after spraying revealed deposit of chemicals adding additives were higher than the control after the simulated rainfall of different time. Deposit of triadimefon/carbendazim+XG-5 combination in wheat leaves were higher than triadimefon/carbendazim+ organic silicon after rainfall of 2h and 4h, showed that capability of thickening agent on the deposit of liquid after simulated rain was better than wetting agent organic silicon.4. Spraying chemicals in the flowering period is the key measure of protection of wheat. Field control test studied not only the synergy of additives to the fungicides, but also the proper time of application of chemical control. The results showed the control effect of spraying chemicals 1d after inoculation of fusarium spores solution was obviously better than 3d and 5d., the control effect of inoculation of fusarium spores solution Id after spraying chemicals was obviously better than 4d and 7d. The control effect of adding four kinds of additives were higher than which of the corresponding CK. When there is the possibility of disease epidemics, we had better to spray chemicals as early as possible, the effect of prevention is better than that of treating after infected.5. Results of field test with simuated rainfall showed that synergism of organic silicon was better than xanthan gum in the treatment without simulated rainfall. Synergism of thickening agent xanthan gum was better than wetting agent organic silicon. Control effect decreased with the increasing time of rainfall:no rain erosion> rain erosion of 2h> rain erosion of 4h> rain erosion of 6h. Control effect of combinations adding additives were all higher than CK, therefore the addition of additives can improve control efficacy of chemicals in controlling wheat scab significantly.