GROWTH OF VICIA-FABA AS AFFECTED BY INOCULATION WITH VESICULAR-ARBUSCULAR MYCORRHIZAE AND RHIZOBIUM-LEGUMINOSARUM BV VICEAE IN 2 SOILS

Desert areas of Egypt are rapidly being planted with faba beans (Vicia faba) to increase the production of this economically important legume. Since indigenous populations of rhizobia or vesicular-arbuscular (VA) mycorrhizae are absent or low in this soil, the objective of the current study was to determine whether inoculation with several strains of Rhizobium leguminosarum bv. viceae and VA mycorrhizae could successfully increase the growth of faba beans. Growth was compared to that in a fertile silt loam soil from the Nile River Valley. The effect of rock phosphate and superphosphate on the faba bean was also examined. The growth of faba beans was increased by dual inoculation with VA mycorrhizae and rhizobia, to a much greater extent than can be attributed to either inoculum on a singular basis. Rhizobium leguminosarum bv. viceae USDA strain 102 F84 was the most effective of the rhizobial strains examined. Growth, plant nutrient content, nodulation, and root colonization were invariably greater in the silt loam soil than the calcareous soil. The addition of rock or superphosphate to soil enhanced these parameters in the calcareous soil, but less than that observed in the silt loam soil. These results demonstrate that the growth of faba beans can be increased in calcareous desert soils by inoculation with rhizobia and VA mycorrhizae. However, the growth remained inferior to that observed in the fertile Nile River Valley soil.