Control of damping-off disease in some plants using environmentally safe biocides

Rhizoctonia solani and fusarium solani are causal agents of damping-off disease. biocides formulations were prepared from the essential oils of fennel,peppermint,oregano and ginger. the potential of these formulations were tested to inhibit the in vitro growth of rhizoctonia solani and fusarium solani. the most effective formulations obtained were used against the in vivo growth of the studied fungi (pot experiment) on gamma-irradiated seeds of squash and tomato,respectively. the in vitro studies showed that the formulated peppermint oil led to complete growth inhibition of rhizoctonia solani and the oregano oil formulation resulted in complete growth inhibition of fusarium solani. the other formulations showed a variably less effect against the investigated fungi. the results of the in vivo experiment revealed that the formulated peppermint and oregano oils significantly minimized the pathological symptoms of the inoculated fungi on the studied plants compared to the control. gamma radiation showed an insignificant result in enhancing the curative effect of the biocides. chemical fungicide demonstrated fewer effects than the formulated biocides. physiologically,the formulated biocides add protection to the plant against fungal infection by increasing the levels of the enzymes; polyphenol oxidase (ppo),peroxidase (pod) and phenylalanine ammonia lyase (pal). the obtained results reveal the potential antifungal effects of biocides against the damping-off disease in squash and tomato and recommend their use as an alternative tool rather than chemical fungicides. © 2017,pakistan botanical society. all rights reserved.