Preharvest application of phellodendron bark extracts controls brown rot and maintains quality of peento-shaped peach

Abstract

Preharvest application of Phellodendron bark (Phellodendron Chinese Schneid) extract (PBE) on brown rot and postharvest quality of peach [Prunus persica (L.) Batsch var. platycarpa (Decne.) L.H. Bailey] was investigated. PBE at 0.8, 1.6, and 3.2 mg·mL-1 totally inhibited conidial germination, mycelial growth, and sporulation, respectively, of Monilinia fructicola in vitro. Preharvest PBE treatment at 21.0 mg·mL-1 at 0, 30, 60, and 90 days after full bloom controlled brown rot caused by M. fructicola on peach fruit after harvest and reduced disease incidence and lesion diameter by 37% and 61%, respectively, than those of the control 96 h after inoculation in in vivo experiments. The results from field experiments were consistent during a 3-year period. Fruit from PBE-treated trees showed higher activities of defense enzymes, including peroxidase, phenylalanine ammonia-lyase, chitinase, and β-1,3-glucanase, compared with those of the control during storage. PBE also delayed softening and loss of titratable acidity and inhibited flesh browning during storage. Total soluble solid contents were unaffected by treatment. The results indicate that preharvest application of PBE may be an alternative for controlling brown rot of peach fruit.