Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide

Abstract

Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination between biocontrol agents and chemical inducers recorded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in field.

Bacillus megaterium-Mediated Synthesis of Selenium Nanoparticles and Their Antifungal Activity against Rhizoctonia solani in Faba Bean Plants

“…These results are similar to studies by Nandini, Hariprasad, Prakash, Shetty and Geetha [ 65 ], which reported that Se-NPs had a highly effective role in controlling plant pathogenic fungus Sclerospora graminicola as a causative agent of downy mildew disease. However, several reports showed that the application of selenium in plants activates the defense plant mechanism against abiotic [ 68 ] and biotic stresses such as R. solani [ 69 ].…”

Improvement of Faba Bean Yield Using Rhizobium/Agrobacterium Inoculant in Low-Fertility Sandy Soil

“…However, production has declined considerably from 523,000 tonnes in 1998 to 158,000 tonnes in 2014 [4]-often a result of susceptibility to foliar diseases, the effects of parasites [5], and/or competition with other crops. Egypt now is the world's largest importer of faba bean; its annual requirement of half million tonnes accounts for over half of global imports [6].…”

Inoculation Techniques for Assessing Pathogenicity of Rhizoctonia solani, Macrophomina phaseolina, Fusarium oxysporum and Fusarium solani on Pepper Seedlings

“…It causes root and/or foot rot of the host plant. Aboveground portions' symptoms can vary based on F. solani species complex and plant species, and the disease may be visible as stunting, wilting and lesions on the leaves and/or stem (Abdel-Monaim, 2013;Coleman, 2016).…”