Plant growth regulators and signal molecules enhance resistance against bacterial blight disease of pomegranate

Abstract

AbstractBacterial blight caused by Xanthomonas axonopodis pv. punicae is a devastating disease causing huge economic losses in major pomegranate growing areas. Thus, this study has been undertaken to assess the effect of plant growth regulators (PGRs) and signal molecules on disease incidence of bacterial blight in addition to its impact on yield and productivity under field condition in disease endemic area. Considering the environmental concern for reduction in synthetics and antibiotics, PGRs offers cost‐effective and an eco‐friendly schedule for management of this disease. Foliar application of ethylene at 200 ppm resulted in significant reduction in disease incidence in leaves (from 33.01% to 4.87%), fruits (from 25.77% to 2.05%) and twigs (from 1.76% and 0.97% to 0%), as compared to untreated plants. Treatment with salicylic acid and paclobutrazol also resulted in reduction of disease incidence. Further, higher accumulation of total phenols and anthocyanin content in rind as well as in arils was observed in ethylene treatment with enhanced fruit yield in pomegranate plants. The enhanced disease tolerance by recording less disease incidence with increased accumulation of defence compounds like phenols and anthocyanins by ethylene, salicylic acid and paclobutrazol treatments resulted in improving fruit yield and quality of pomegranate fruits. Thus, judicious application of PGRs and signal molecules contributed for induction of resistance while improving developmental and reproductive parameters of pomegranate and thus could be a viable option for their synergistic use in pomegranate farming.