Effect of levels and sources of phosphorus and phosphate solubilizing microorganisms on growth, yield and quality of sugarcane

Field investigations were carried out at Regional Research Station, Visweswaraya Canal Farm, Mandya (Karnataka) to study the effect of soil inoculation of phosphate solubilizing organisms (PSM) in conjunction with levels and sources of P on growth, yield and quality of sugarcane-Plant and ratoon during 1995 to 1998. The bacterial cultures viz.,Agrobacterium radiobacter andBacillus megaterium in plant crop and the fungusAspergillus awamori in ratoon crop are efficient P solubilizers. Their inoculation with soluble P source viz., SSP and in combination with pressmud (PM) ascentuates their effect as P solubilizers. Enhanced uptake and higher tissue indices of P besides N and K were indicative of better nutrient use efficiency and their positive influence on various growth and yield parameters. Improvement in cane yields (8 to 10%), economy in fertilizer P (25%) are suggestive of cost effectiveness and higher net returns due to their inoculation.