The Antibacterial Effect of the Extract of Eupatorium indica Leaves on Two Main Postharvest Diseases of Pineapple

Abstract Phytophthora nicotianae var. Parasitica and Thielaviopsis paradoxa, often occur in pineapple production. In order to explore the bacteriostatic effect of the extract on the pathogen of pineapple disease, and to provide theoretical basis for the application of the extract on the prevention and control of pineapple fungal disease, the antibacterial activity of three extracts of Eupatorium adenophorum against two pathogenic bacteria of pineapple was studied. Two components with antibacterial activity extracted from the leaves of Eupatorium indica leaves were used as “fungicide”. The antibacterial effects of the three extracts on the pathogens of pineapple heart rot and black rot were studied. The results showed that the crude extracts of H, B, and C components at a concentration of 2 mg / ml against pineapple heart rot and black rot pathogens reached 76.14%, 77.94%, 80.40% and 40.15%, 60.50%. The EC90 values of the crude extracts H, B, and C for pineapple heart rot were 4.48, 2.67, and 4.45 mg / ml, respectively. Respectively, the EC90 values for pineapple black rot pathogens were 10.60, 7.17, and 3.27 mg / ml. Relatively speaking, the three kinds of extracts have better antibacterial effects on pineapple heart rot pathogens than pineapple black rot pathogens; B and C two component substances have great potential to prevent and cure pineapple heart rot and black rot.