Effect of Biofertilizer Phosphate on Grain Yield and Its Components of Maize (Zea mays L.) cv. KSC704 under Water Deficit Stress Conditions

To study the effect of biofertilizer phosphate on grain yield and its componants of maize cv. KSC704 under deficit water stress conditions, a field experiment was carried out in Ilam Agricultural Research Field Station, Ilam, in 2008 and 2009 growing seasons. Split factorial arranagements in randomized complete block design with three replications was used. Main plots were assigned to three irrigation levels, irrigation after 70 = I1, 100 = I2 and 130 = I3 mm cumulative evaporation from class A evaporation pan. Sub-plots consisted of factorial arrangements of two levels of biofertilizer phosphate; B0= no biofertilizer phosphate and B1= with biofertilizer phosphate and three levels of chemical phospours fertilizer; P1= 0, P2= 45 and P3= 90 kgha-1. Results showed that biofertilizer phosphate significantly increased grain yield in the water deficit conditions (I2 and I3). The highest grain yiled (9090 kgha-1), yield components and HI was obtained from integrated application of biofertilizer and 45 kgha-1 chemical fertilizer in optimum irrigation regime. However, in mild water deficit stress conditions, the highest grain yield (8098 kgha-1) was also obtained by application of the same fertilizer treatment. 1000 KW was also heavier for this fertilizer treatment in I1 with 356.6 g, and it was 335 g in I2. It can be concluded that biofertilizer phosphate could improve tolerance of maize plant to water deficit stress and reduce the usage of chemical fertilizer.