Effect of nitrogen biofertilization on snap bean plants grown in substrate cultures

Two studies were conducted at Arid Land Agricultural Research and Services Center (ALARC), Faculty of Agriculture, Ain Shams University, Egypt, during the two Successful seasons of 2007/2008 and 2008/2009 for each study, snap bean seeds (PhaseoIus vulgaris) cv, Goya (round type) was used in both experiments. The aim of the first study was to investigate the ability of using different inoculation timing (0, 7, 14 and 21 days from sowing) of snap beans using Rhizobium using peat moss mixed with sand (1:1 v/v) in pots under plastic greenhouse condition to determine the suitable timing of inoculation in substrates culture .The obtained results showed that inoculation after 14 days of sowing gave the best results of growth expressed as, plant height and plant dry weight, and nodulation (number of nodules). These results highlight the importance of timing of inoculation for Successful nodulation .While, the second study was conducted to investigate the ability of using Rhizobium inoculation to reduce N fertilizer, type of containers and its effect on the growth and yield of snap bean (Phaseolus vulgaris) c:v Goya Four different nitrogen rates (25, 50, 75,100 N% plus Rhizobium) combined with two different types of containers (container and pots) were used in this investigation. The experimental design was split plot with three replicates. Vegetative growth and yield characters, physical and chemical analysis of snap bean pods of and nitrogenase activity were measured .Data showed that using container system had a positive effect on plant height, chlorophyll reading, early yield, total yield, TSS, total protein of pods, water use efficiency and nitrogen use efficiency compared to pot system .Using 100 % N with or without inoculation recorded the highest vegetative growth and yield characters followed by 50 % N with Rhizobium inoculations. Increasing nitrogen rates led to increase the values of plant height, chlorophyll reading, early yield and total yield .On the other hand, number of nodules and nitrogenase activity were significantly the highest with 50% N plus R. Finally the highest water use and water consumption efficiency were recorded by container system combined with 100% N while the highest N use efficiency was recorded by container system combined with 25% N plus Rhizobium.