BIOCONTROL OF FUSARIUMNl.l DISEASE IN CUCUMBER WITH IMPROVEMENT OF GROWTH AND MINERAL UPTAKE USING SOME ANTAGONISTIC FORMULATIONS

摘要

Fusarium wilt disease in Cucumber (Cucumis sativus L.) is widespread, responsible for serious economic losses. Amongst totally 15 isolates of Fusarium spp., obtained from different localities of Sohag gover-norate, Egypt, only the identified isolatesas F. oxysporum were pathogenic on cucumber Denmark Beta-Alpha cv. and caused wilt symptoms. Totally 22 isolates of Trichoderma spp., B. subtilis and Pseudomonas spp., were obtained from rhizosphere of cucumber and some available commercial formulationsand then tested for antagonistic activity against F. oxysporum (F05) in vitro. The highest inhibitory effect on growth of F05 was observed by isolate Trichodex of T. harzianum (89.29%) followed by Th4 of 7". harzianum, Serenade and MBI 600 of B. subtilis, PS3 of Pseudomonas spp., and Treico and Tv2 of 7". viride. Pot experiments were performed to investigate the effects of formulated antagonists as seed treatment on Fusarium wilt incidence, growth and mineral uptake of cucumber. Results showed that alltested formulations significantly reduced percent of wilted plants and disease severity, and improved plant growth by increasing length of shoot and root, fresh and dry weight of shoot and root system, and number of leaves and flowers per plant comparedwith untreated control. They also significantly increased nutrient contents of plant shoot including N, P, K, Ca, Fe, Mn, Cu, and Zn. Magnesium content in shoot slightly not significantly increased. Formulation of Trichodex was the most effective ones followed by Serenade, Th4 and PS3.