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 legum e. Since indigenous populations of rhizobia or vesicular-arbuscular (V A) mycorrhizae are absent or low in this soil, the objective of the cu rrent study was to determine whether inoculation with several strains of Rhizobium leguminosarum bv. viceae and VA mycorrhizae could success fully increase the growth of faba beans. Growth was compared to that i n a fertile silt loam soil from the Nile River Valley. The effect of r ock phosphate and superphosphate on the faba bean was also examined. T he growth of faba beans was increased by dual inoculation with VA myco rrhizae and rhizobia, to a much greater extent than can be attributed to either inoculum on a singular basis. Rhizobium leguminosarum bv. vi ceae USDA strain 102 F84 was the most effective of the rhizobial strai ns examined. Growth, plant nutrient content, nodulation, and root colo nization were invariably greater in the silt loam soil than the calcar eous soil. The addition of rock or superphosphate to soil enhanced the se parameters in the calcareous soil, but less than that observed in t he silt loam soil. These results demonstrate that the growth of faba b eans can be increased in calcareous desert soils by inoculation with r hizobia and VA mycorrhizae. However, the growth remained inferior to t hat observed in the fertile Nile River Valley soil.