Applying Rice Seed-Associated Antagonistic Bacteria to Manage Rice Sheath Blight in Developing Countries

Abstract

Mew, T. W., Cottyn, B., Pamplona, R., Barrios, H., Xiangmin, L., Zhiyi, C., Fan, L., Nilpanit, N., Arunyanart, P., Kim, P. V., and Du, P. V. 2004. Applying rice seed-associated antagonistic bacteria to manage rice sheath blight in developing countries. Plant Dis. 88:557-564.One promising area of disease management for resource-poor farmers that emerged in recent years in developing countries is the potential of biological control. Biological control agents (BCAs) were found to be ubiquitous in the rice ecosystem. Seed bacterization with BCAs appeared to promote plant growth. BCAs showed efficacy on sheath blight (Rhizoctonia solani AG 1) but produced inconsistent results over time in the field using it alone. The control efficiency ranged from 50 to over 90%, with a high variance. To improve the efficacy, a half-dose of a commonly used fungicide, like Jingangmycin in China and Validamycin in Vietnam, was introduced to mix with BCAs and was found to be effective, and it reduced the variance of the field performance tests. To scale up the BCA technology for resource-poor farmers, a participatory approach, engaging the farmers to evaluate the product, was initiated in China and Vietnam. The BCA strain that is indigenous at a locality is mass produced at the research institution based on the total area required for application, as relayed by the farmers to extension workers. The demand by farmers would serve as the basis for the amount to be produced and for delivery to the rice farmers who were participating in the trials and, later, to those farmers who ordered the product. This process alleviates BCA storage and shelf-life problems. Data from the field performance trials also were used by the researchers to apply for registration for commercial use of BCAs. Scaling up to extend the BCA technology to more rice farmers as an integral part of their pest management scheme, in particular, and crop management practices, in general, is foreseen in the near future.

Penyakit Hawar Pelepah (Rhizoctonia solani) pada Padi dan Taktik Pengelolaannya

“…Sklerosium jamur R. solani mampu bertahan hidup selama satu tahun di dalam tanah. Sklerosium dan miselium dalam serasah jerami dapat tersebar selama proses pengolahan tanah dan sangat berperan sebagai inokulum awal penyakit untuk musim tanam berikutnya (Mew et al, 2004).…”

Water-soluble granules containing Bacillus megaterium for biological control of rice sheath blight: formulation, bacterial viability and efficacy testing

“…More recently, B. subtilis has been reported for controlling sheath blight disease of rice in Jiangsu, China (Mew 2004). The present work reports an improved formulation of water-soluble granular form to suppress sheath blight disease.…”

“…For sheath blight disease, fresh cells of potential bacterial antagonists were originally used to control sheath blight disease for research purpose (Mew and Rosales 1986;Vasantha Devi et al 1989;Gnanamanickam and Mew 1990;Gnanamanickam et al 1992). More recently, bacterial formulations have been developed and used to combat sheath blight disease of rice in some developing countries (Vasudevan et al 2002;Mew et al 2004). In China, for instance, a liquid formulation has been extensively tested to control sheath blight disease in farm ricefield conditions (Mew et al 2004).…”

“…More recently, bacterial formulations have been developed and used to combat sheath blight disease of rice in some developing countries (Vasudevan et al 2002;Mew et al 2004). In China, for instance, a liquid formulation has been extensively tested to control sheath blight disease in farm ricefield conditions (Mew et al 2004). Although, this type of formulation can be produced in large quantity using a simple fermentation and formulation processes, it may be difficult to store and may have a relatively short shelf life.…”

Ultrastructural studies on the interaction between Bacillus subtilis MBI 600 (Integral) and the rice sheath blight pathogen, Rhizoctonia solani

“…Presently, bio-formulations of PGPR are being used for ShB management in some developing countries (Vasudevan et al, 2002;Mew et al, 2004). Understanding the exact mechanism of action of these bacterial formulations is necessary for devising effective management strategies for ShB in the field.…”