Effectiveness of Certain Biocides and Essential Oils in Controlling Damping-Off and Root-Rot Diseases of Soybean (Glycine max (L.) Merr.)

Abstract

Damping-off and root-rot are some of the most important diseases attack soybean (Glycine max (L.) Merr.) in Egypt. The effect of biocides, i.e. Bio-Cure-F, Plant guard, and Rhizo-N, and essential oils of eucalyptus, thyme, and lemongrass oils, as well as the fungicide Vitavax-200, were evaluated in vitro, greenhouse and under field conditions during the two successive growing seasons, 2018 and 2019 to control damping-off and root-rot diseases of soybean. All the tested biocides and essential oils used significantly inhibited the linear growth of the tested pathogenic fungi, i.e., Fusarium moniliforme, Fusarium solani and Rhizoctonia solani compared with the control. Under greenhouse and field conditions in both growing seasons, obtained results indicated that all the tested biocides and essential oils significantly reduced the percentages of soybean damping-off and root-rot severity furthermore improved photosynthetic pigments content, growth parameters, and seed yield. Vitavax-200 and Plant guard gave the highest values of reduction in this respect, followed by Rhizo-N, lemongrass oil, Bio-Cure-F, thyme oil, and eucalyptus oil respectively. Besides, the quality parameters of soybean seeds showed a favorable elevation in total oil content, on the contrary, there was a general decrease in the seeds protein content. However, the correlations between seeds oil and protein contents were negatively correlated. It could be concluded in biocides and essential oils examined can be recommended for biocontrol of soybean damping-off and root-rot diseases.