Use of aqueous and cow urine based plant extracts against post-harvest diseases of apple.

摘要

The efficacy in vitro of water and cow urine-based botanical formulations against important postharvest pathogens of apple (Alternaria alternata, Botrytis cinerea, Glomerella cingulata, Botryosphaeria, Penicillium expansum, Rhizopus stolonifer and Trichothecium roseum) was evaluated. Six plants (Bougainvillea glabra, Melia azedarach, Eucalyptus globulus, Roylea elegans, Dodonaea viscosa and Mentha piperita) were evaluated as Field Formulations I (FF-I, with water) and II (FF-II, with cow urine), each at 10, 25 and 50%. FF-II resulted in 69.8-93.4% reduction in the mycelial growth of the pathogens in comparison to 53.5-84.1% reduction in FF-I at 10.0%. Increase in the concentration of these formulations resulted in higher inhibition of the mycelial growth. As FF-II was found effective in vitro against the pathogens, its efficacy against postharvest rots of apple was evaluated and compared with wax coating (Carnauba wax) and chemical treatment (fruit dip) in fungicide Saaf. The efficacy of FF-II was evaluated as direct skin coating of fruits and also by impregnating the butter paper wrappers which were then used for covering the fruits. Fruits wrapped in wrappers impregnated with FF-II was found at par with fruit dip in Saaf, with 80% reduction in fruit rot compared to the control at 75 days after storage. Though fruit firmness was highest (15 lbs per square inch) in fruits coated with wax, fruits wrapped with impregnated wrappers with FF-II and fruit dipped in Saaf also had fruit firmness of 14 lbs per square inch compared to 11 lbs in the control. Total soluble solids (TSS) was lowest (13.5%) in fruits coated with wax. FF-II also had lower (15 and 1.5) TSS compared to other treatments. Fruit dip in Saaf was the most effective in reducing surface microflora (87.7%), while FF-II resulted in 85.2% reduction.