Preparation And Application Of Multiwalled Carbon Nanotube Supported Metconazole Seed Coat For Wheat

Wheat sharp eyespot is an important soil-borne disease.Metconazole is a new triazole broad spectrum fungicide,which has good control effect on soil-borne diseases.Multiwalled carbon nanotubes are a new type of adsorbent material with large surface area and strong adsorptivity.In this thesis,three kinds of porous materials were used as the carrier to carry metconazole.On the basis of screening and optimization of seed coating agent,wheat seed coating agent was prepared by wet grinding method.The laboratory and field tests of the developed seed coating agent were carried out,which provided the basis for the use of metconazole in wheat seed coating agent.The main results of the study are as follows:1.The influences of stirring rate,feeding ratio and stirring time on the adsorption effect were experimentally studied.Finally,the multi-walled carbon nanotubes were determined as the best adsorption material,and the optimal loading conditions were stirring time of 30 min and feeding ratio of 6:1,at which the adsorption rate was 85.27%.2.Orthogonal test was used to screen the dispersant,emulsifier,antifreeze and film forming agent of wheat seed coating agent.The final optimized formula was as follows: 1.5%dispersant sodium wood,1% emulsifier BY-112,2%AEO-15,3% glycol as antifreeze,3%film forming agent,4% dye.3.The results of laboratory safety experiment showed that when the ratio of drug to seed was 1:25,1:50,1:100 and 1:200,the indicators of wheat emergence rate and germination potential under the treatment of drug loaded seed coating agent were higher than those of control agents,and the emergence rate reached 92.22% when the ratio of drug to seed was1:200.The indexes of root length,seedling length,fresh weight and dry weight of wheat were better than those of control agents,this shows that the loading of metconazole has a better mitigation effect on the drug damage of metconazole.4.The results of field plot experiment showed that at the seedling stage,the indices of root length and plant height of wheat treated with drug-loaded seed coat were higher than those of control drug and CK,but the plant height was lower than CK;The plant height of wheat was significantly higher than that of CK at tillering stage,indicating that the drugloaded seed coating played a certain role in controlling release.5.The results of wheat sheath blight control test showed that the control effect was significantly higher than that of the control agents when the ratio of drug to seed was 1:25,1:50,1:100 and 1:200,and the control effect reached 86.14% when the ratio of drug to seed was 1:25,indicating that the loading of metconazole could prolong the efficacy time.