Biological control of downy mildew of maize caused by Peronosclerospora sorghi under environmentally controlled conditions

Abstract

Downy mildew disease, caused by Peronosclerospora sorghi, is one of the most serious diseases of maize. The disease is currently managed by seed treatment with metalaxyl fungicides. However, problems regarding environmental pollution resulting from the use of fungicides and development of fungicide resistance within populations of P. sorghi are of increasing concern. Assuming that biological control by means of using antagonistic microorganisms may be an alternative for the management of this disease, the efficacy of biocontrol agents viz., Bacillus subtilis G1, Bacillus amyloliquefaciens B2, Brevibacillus brevis 57 and Pseudomonas fluorescens Pf1 for the management of downy mildew of maize and for promoting plant growth was evaluated. The results indicated that seed treatment with B. subtilis G1 and B. amyloliquefaciens B2 significantly (P = 0.05) increased the germination percentage and seedling vigour of maize as assessed by roll towel method. Among them, B. subtilis G1 was the most effective and recorded 9% and 31% increases in germination percentage and seedling vigour of maize respectively, as compared to the control. A talc- based powder formulation of B. subtilis G1 when applied through seed at the rate of 10 g/kg reduced the downy mildew incidence up to 54% under greenhouse conditions. Results of this study suggest that B. subtilis G1 is a promising bioagent for the management of downy mildew of maize and for promoting plant growth. This antagonist could be further exploited for commercial scale up for ecofriendly management of downy mildew of maize under localized climatic conditions.

Efektivitas Isolat-Isolat Bacillus sebagai Pengendali Penyakit Bulai dan Pemacu Pertumbuhan Tanaman Jagung pada Kondisi Terkontrol

“…Benih yang telah ditanam dalam kertas gulung (roller) diinkubasi pada suhu ruang 25±2°C selama satu minggu. Perlakuan sama untuk masing-masing isolat dan kontrol (Sireesha & Velazhahan, 2016).…”

“…Agens hayati Bacillus sublilis G1 telah dilaporkan dapat menekan kejadian penyakit hingga 50%, selain itu B. subtilis G1 tersebut mampu meningkatkan persentase perkecambahan dan memperbaiki vigor tanaman jagung (Sireesha & Velazhahan, 2016). Namun, di Indonesia pengembangan agens hayati untuk penyakit bulai sekaligus sebagai pupuk hayati ini masih terbatas.…”

Discovery of a New Fungicide Candidate through Lead Optimization of Pyrimidinamine Derivatives and Its Activity against Cucumber Downy Mildew

“…Downy mildew is one of the most highly destructive of the diseases that cause serious damage to fruits, vegetables, and other economic crops. − Along with an increase in the standard of living, the demand for a greater quality and quantity of fruits and vegetables increases daily. Consequently, the demand for relevant fungicides against downy mildew is being enhanced.…”