RICE PERFORMANCE AND NATURAL INFECTION WITH BLAST (PYRICULARIA-ORYZAE CAV) UNDER DIFFERENT ALGALIZATION TECHNIQUES AND RATES OF FERTILIZER NITROGEN

Japonica rice, Giza 171, was inoculated with either a dry or fresh soil-based inoculum of cyanobacteria containing Anabaena cylindrica, Anabaena oryzae, Nostoc muscorum and Tolypothrix tenuis together with fertilization with urea at 0, 36, 72, or 108 kg N/ha. Fresh inoculum enhanced plant growth, yield and N content in comparison with the dry one. The efficiency of nitrogen utilization from the urea at all N concentrations was improved by using the fresh inoculum. Natural infection with leaf and neck blast caused by Pyricularia oryzae Cav. increased with increasing N fertilization. Algalization with the fresh inoculum decreased leaf blast while neck blast was slightly higher in the algalized sub-plots but without considerable yield damage.