Screening Potential of Some Bacterial Species and Trichoderma hrzianum Against Sclerotinia sclerotiorum on Cucumber.

Abstract

Eight bacterial isolates belonged to 4 genera, i.e., Serratia sp.,(one isolate) Bacillus subtilis, (three isolates) Bacillus thuringiensis,(two isolates) Streptomyces sp.(one isolate) and Pseudumonas flourescens(one isolate) and one fungal isolate (T. harzianum) were isolated from cucumber rhizosphere to evaluate their potential as antagonists to Sclerotinia stem and root rot on cucumber. In vitro, all isolates resulted in a significant reduction in hyphal growth of pathogenic fungus, Streptomyces sp. was more significantly reduced mycelium growth followed by P. flourescens and Bacillus subtilis (Bs1) (72.22, 68.0 and 62.22 %); respectively. All isolates gave a significant reduction in disease severity on cucumber plants, B2, Bs1, Bs2 and Streptomyces sp. isolates gave best reduction in disease severity. All isolates resulted in significant increase in morphological parameters of cucumber plants (stem and root length, foliage and root dry weight) compared to control.

The Use of Rhizobacteria on White Rot Disease and Growth of Lettuce

“…The inhibitory effect of Pseudomonas spp. AFP104 isolate on mycelial growth of S. sclerotiorum was reported as 83.3% by Soylu et al (2005), while the inhibition ratio of pathogenic fungus by Streptomyces sp., Pseudomonas fluorescens and Bacillus subtilis (Bs1) bacteria was 72.2, 68.0, 62.22%, respectively (Helmy, 2016). El-Tarabily et al (2000) reported the inhibitory effect of Serratia marcescens, Streptomyces viridodiasticus and Micromonospora carbonacea, on the growth of S. minor in vitro.…”