RELATION SOIL AMENDMENTS AND MICROBIAL ANTAGONISTS FOR BIOLOGICAL CONTROL OF NEMATODES
Dr. Hamid Abbasi Moghaddam,
Dr. Nasser Panjehkeh
Journal Title:International Journal of Medical Studies
Plant parasitic nematodes are important factors affecting crop growth and yield in all agricultural production zones. However, chemical nematicides are now being reappraised in respect of environmental hazard, high costs, limited availability in many developing countries or their diminished effectiveness following repeated applications. This review presents progress made in the field of microbial antagonists of plant−parasitic nematodes, including nematophagous fungi, endophytic fungi, actinomycetes and bacteria. A wide variety of microorganisms are capable of repelling, inhibiting or killing plant−parasitic nematodes, but the commercialisation of these microorganisms lags far behind their resource investigation. One limiting factor is their inconsistent performance in the field. No matter how well suited a nematode antagonist is to a target nematode in a laboratory test, rational management decision can be made only by analysing the interactions naturally occurring among "host plant nematode target soil microbial control agent (MCA) environment". Organic soil amendments stimulate the activities of microorganisms that are antagonistic to plant parasitic nematodes. The decomposition of organic matter results in accumulation in the soils of special compounds that may be nematicidal. Amendments are mainly bio products and wastes from industrial, agricultural, biological and other activities. Control of plant parasitic nematodes can be by improvements of soil structure and fertility, alteration of the level of plant−resistance, release of nemato toxic compounds), parasites (fungi and bacteria) and other nematode antagonistic (biological control agents). The mode of action of organic amendments leading to plant disease control and stimulation of microorganisms is complex and dependent on the nature of the amendments.
KEYWORDS: Biological control, Microbial control, Plant parasitic nematode.