Utilization of vesicular–arbuscular mycorrhizal fungi in agriculture

Abstract

Commercial use of vesicular–arbuscular mycorrhizae (VAM) may be an alternative to rising agricultural energy and fertilizer costs. Vesicular–arbuscular mycorrhizae may be able to increase crop yields while reducing fertilizer and energy inputs. Since mycorrhizal fungi are naturally present in most soils, their unique fertilizer abilities are already being utilized by most crop plants. Commercial uses of VA mycorrhizal fungi are therefore currently restricted to situations where the natural populations of VAM fungi have been destroyed or damaged such as in fumigated or chemically treated areas, greenhouses, and disturbed areas such as coal spoils, strip mines, waste areas, or road beds. Commercial production of VAM inoculum is presently being attempted at several locations in the U.S. Vesicular–arbuscular mycorrhizal inoculum is produced by growing VAM fungi on the roots of suitable host plants under aseptic greenhouse conditions The inoculum consists of the host-plant growth medium and host roots associated with VAM hyphae and spores which have been ground and dried. Most large-scale uses of VAM involve the establishment of the mycorrhizae on seedlings which will be transplanted to the field. Large-scale methods for direct inoculation with VAM have not yet been devised, but in small trials, layering, banding, broadcasting, and pelleting seed with VAM inoculum have proved effective. Methods for determining what soils are most likely to benefit from applications of VAM fungi are available. The potential for employing VAM fungi on a wide scale in agriculture is dependent on the development of crop growth-promoting strains of VAM which are superior to native soil populations of VAM fungi.

Effect of VAM on Drought Tolerance and Growth of Plant in Comparison with the Effect of Growth Regulators

“…Under adverse conditions several internal and external factors e.g., growth regulators, changes in level of inoculation with VAM fungus ameliorate the adverse affects of drought. The use of VAM fungi in cultivated crop can be important factors in increasing productivity even under adverse conditions as well as enhancing a more rational use of fertilizers (Menge, 1983). Under low moisture levels, water absorption capacity of roots might be enhanced by mycorrhiza.…”

<i>Gigaspora (GIGASPORACEAE) </i>da India, com notas morfo-taxonômicas </htm>

“…The roots of host plants were checked for AM colonization after 45 days. Pots showing successful mycorrhization were maintained for period of six months and application of water was reduced at final three weeks to maximize spore production (MENGE, 1982). At the end of 6 months the plants were cut near the base, the cultures were air-dried and checked for the presence of spores.…”

Efeitos da inoculação micorrízica em mudas de gravioleira em solo fumigado e não fumigado

“…a eficiência simbiótica e potencial de inóculo de fungos micorrízicos indígenos (Ikram et al, 1992;Siqueira,1994). A eficiência do fungo indígeno é um dos fatores-chaves para o funcionamento de inoculação micorrízica no solo não fumigado (Menge, 1983). Os resultados mostraram que a gravioleira é uma planta que se beneficia de FMAs para seu desenvolvimento.…”