INOCULATION OF SORGHUM (SORGHUM-BICOLOR) WITH GLOMUS-VERSIFORME UNDER FIELD CONDITIONS

The effect of preceding crops (wheat, chickpea, fallow), on the response of sorghum to inoculation with Glomus versiforme was assessed under field conditions in a phosphorus-deficient sandy loam. Wheat and chickpea increased the number of propagules of indigenous VAM fungi 3-5-fold compared with fallow soil. Inoculation with G. versiforme in fallow soil increased the level of infection in roots compared with the control. However, a similar effect of inoculation, when wheat and chickpea were the preceding crops, was not observed. Inoculation with G. versiforme increased sorghum growth by 10, 28 and 29% under wheat-, fallow-, and chickpea-sorghum rotations, respectively. This also resulted in 15-47% increase in the uptake of phosphorus. The largest increases in shoot dry weight (39%) and in uptake of phosphorus (54%) were, however, obtained by application of single superphosphate (60 kg P2O5 ha-1)