INCREASED YIELDS AND PHOSPHORUS UPTAKE BY WESTAR CANOLA (Brassica napus L.) INOCULATED WITH A PHOSPHATE-SOLUBILIZING ISOLATE OF Penicillium bilaji

Abstract

Greenhouse and field experiments were conducted to evaluate the effect of inoculation with a phosphate-solubilizing isolate of Penicillium bilaji on the yield and phosphate uptake by canola (Brassica napus L.). Under greenhouse conditions, P. bilaji inoculation did not affect canola pod or straw dry matter production, but did increase straw and pod P concentrations resulting from increased P uptake over uninoculated treatments. Addition of P at 20 mg kg−1 soil as Florida rock phosphate plus inoculation with P. bilaji resulted in P uptake by canola nearly equivalent to that resulting from the addition of monoammonium phosphate (MAP) alone at the same rate of P. Addition of Florida rock phosphate alone had much less effect on plant P uptake. Addition of P. bilaji generally increased dry matter yields and P uptake by canola in two field sites. Penicillium bilaji appears to be able to increase the uptake of P from sources unavailable for plant uptake; P uptake by control plants inoculated with P. bilaji absorbed as much P as that absorbed by uninoculated plants receiving MAP. Key words: Penicillium bilaji, Brassica napus, fertilizer efficiency, rock phosphate, monoammonium phosphate