Boosting biopesticide potential of Trichoderma harzianum for controlling the downy mildew and improving the growth and the productivity of King Ruby seedless grape

Abstract Background Plasmopara viticola, the causal agent of grape downy mildew, is one most serious diseases. Application Trichoderma harzianum grown on different potato dextrose supplemented broth media using some chemical inducers (TSDCIS), i.e., thiamine (T2), a mixture micronutrients (T3) and potassium tartrate (T4), compared to without amendment (T1), was conducted under field conditions evaluate potential T. against improving growth, as well yield quality, quantity. Results Foliar application all TSDCIS significantly reduced disease severity increased phenolic content, peroxidase, polyphenol oxidase enzyme activity, growth parameters, parameters. growing medium with (T4) achieved significant reduction in (78.9, 81.8%) than control treatment two seasons, respectively. In contrast, it decreased H 2 O lipid peroxidation, cellular electrolyte leakage. Scanning electron microscopy observations revealed that number opened stomata, average stomatal area, pore area response T4 treatment. Conclusions It can be concluded biosafety mildew improve its yield, fruit quality recommended.