EFFECT OF PHOSPHORUS, PLANT DENSITIES AND PLANT TYPES ON DIFFERENT GROWTH AND PHYSIOLOGICAL-PARAMETERS OF SOYBEAN (GLYCINE-MAX)

A field experiment was conducted during 1986 and 1987 to study the eff ect of P, plant densities and plant types on growth and physiological parameters of soybean [Glycine mar (L.) Merr.] growing on P-deficient Vertisol at Mandsaur. Plant height, dry weight, trifoliates/plant, bra nches/plant, relative growth rate and leaf-area duration significantly increased with P up to 40 kg/ha. Fresh weight, number of root nodules , leaf-area index, net assimilation rate and crop-growth rate signific antly increased up to 80 kg P2O5/ha. All growth and physiological para meters performed well at 0.4 million plants/ha except plant height, le af-area index, crop-growth rate which were superior at 0.8 million pla nts/ha. Erect plant type ('JS 75-46') was superior for almost all grow th and physiological parameters, but spreading type ('JS 72-44') was s uperior for trifoliates and branches/plant.