Effect of Groundnut – Sesame Intercropping and Nitrogen Fertilizer on Yield, Yield Components and Infection of Root – Rot and Wilt Diseases

The interaction between cropping system and mineral nutrients (nitrogen) is an important factor affecting yield and its attributes of legumes. A two year-study was carried out at Ismailia Agricultural Experiments and Research Station, ARC, Ismailia governorate, Egypt, during 2010 and 2011 summer seasons to study the effect of intercropping sesame with groundnut and three rates of nitrogen fertilization on yield and its attributes, as well as, root – rot and wilt diseases for both crops. Intercropping pattern 3 groundnut : 1 sesame recorded higher groundnut yield and its attributes than 2:2 pattern, while, the highest sesame yield and its attributes was obtained by 2:2 pattern. Increasing nitrogen fertilization rates from 107.1 to 178.5 kg N per ha resulted in significant increment in yield and its attributes of both crops. Land equivalent ratio (LER) ranged from 1.22 to 1.44. LER Values of 2:2 pattern exceeded 3:1 pattern. The highest LER was obtained when growing sesame with groundnut in 2:2 pattern and using the highest rate of nitrogen fertilization (178.5 kg N per ha). The relative crowding coefficient (RCC) in 2:2 was associated with relatively heavy competition rather than 3:1 pattern. The lowest aggressivity was associated with 2:2 pattern and fertilized with 142.8 kg N per ha. The highest Monetary advantage index was also associated with 2:2 pattern when received the highest rate of nitrogen fertilization (178.5 kg N per ha). The gradual increase of nitrogen fertilization rates resulted in increases the percentage of dead groundnut and sesame plants under the two intercropping patterns during the two seasons. Intercropping pattern 2:2 increased the total counts of fungi and bacteria isolated from soil than the other intercropping pattern. Increasing nitrogen fertilization rates from 107.1 to 178.5 kg N per ha increased the total fungi count, whereas, it decreased the total bacteria count.