Abstract: Using Aspergillus niger extract as the test material, single factor test screening and response surface analysis were used to optimize the preparation of Aspergillus niger extract water-dispersible tablets, and the effects of Aspergillus niger extract water-dispersible tablets on tobacco agronomic characteristics and physiological and biochemical indicators were studied through field applications impact. The results of the study showed that the best formula for water-dispersible tablets of Aspergillus niger extract was: 10% Aspergillus niger extract, disintegrant ratio (acid-base) 0.45, 36% disintegrant, 6% polyethylene glycol 6000, 2% Polyvinylpyrrolidone K30, filled with fillers, the Aspergillus niger extract water-dispersible tablets prepared under these conditions had a smooth surface, moderate particle strength and low viscosity with suspension rate 80.56%, pH 5.71, and disintegration time 130.2 s. It met the quality and technical indicators of pesticide formulations. The results of field experiments showed that compared with the control, the number of leaves of tobacco using Aspergillus niger extract water-dispersible tablets increased by 68.35%-89.83%, the leaf length increased by 9.54%-30.18%, the leaf width increased by 23.37%-29.38%, and the stem diameter was increased by 23.37%-29.38%. The thickness increased by 66.40%-97.36% and the plant height increased by 5.80%-16.30%; under the action of the tablet, the field control effect of tobacco bacterial wilt reached more than 50%, it improved the adaptability of tobacco to the unfavorable environment and promoted plant growth and environmental resistance.

Key words: Aspergillus niger extract, water-dispersible tablet, agronomic traits, physiological and biochemical indexes, anti-disease