Induces Resistance Against Fusarium and Pink Rots by Acibenzolar-S-Methyl in Harvested Muskmelon (cv. Yindi)

Acibenzolar-S-methyl (ASM) is a chemical activator of systematic resistance in many plants. The effect of preharvest and postharvest application of ASM was evaluated for its ability to induce resistance in muskmelon fruit. The results indicated that 50 and 100 mg L−1 ASM or 1 mL L−1 imazalil at 1 week or 1 day before harvest were effective in reducing the lesion area with 100 mg L−1 ASM the most effective. No treatment inhibited the infection rate. The postharvest results showed that 50 and 100 mg L−1 ASM, and 0.1 mL L−1 imazalil were effective in reducing the lesion area with 100 mg L−1 ASM the most effective. No treatment inhibited the infection rate. There was a clear time-dependent response of the fruit to postharvest ASM treatment, in which treatments applied 1, 3, and 5 day before inoculation provided the best results. ASM did not demonstrate any fungicide effect in vitro and suppressed lesion area in treated muskmelons, indicating that disease resistance was induced. The protection of ASM was associated with the activation of peroxidase (POD) in treated muskmelons.