EVALUATION OF ECONOMIC PRODUCTIVITY FODDER AND GRAIN YIELD OF SORGHUM (Sorghum bicolor (L) Moench) AS INFLUENCED BY VARIETY AND CUTTING TIME UNDER SEMI-ARID ENVIRONMENTS

The potential of sorghum to meet food, feed and farm income needs of smallholder farmers in arid areas of Kenya relies on the identification and cultivation of appropriate varieties. Sorghum cultivation for food grain and quality fodder from the same crop is not well established among varieties in Kenya. The fodder– cum–grain yield potential of important varieties required to be identified to enable farmers in semi-arid areas to select appropriate varieties and crop management programs to maximize economic returns. Field trials were conducted at Kenya Agricultural and Livestock Research Organization, Kiboko, Kenya during season 1 (October – December 2013) and season 2 (March -May, 2014). The objectives of the trials were; to determine the fodder and grain yield in sorghum varieties cut at different times, the effect of cutting time on yield components of sorghum varieties and the sorghum cutting time that maximizes economic returns to farmers. The experimental design was split plot in a randomized complete block design and replicated thrice. The main plot treatments were four cutting times; No cut, Cutting 40 days after sowing, Cutting 75 days after sowing and Cutting 40 then 75 days after sowing respectively. The sub-plot treatments were four varieties Gadam El Hamam (Vg), Mexico R Line 5 (Vm), KAT 369 X F6 YQ 212 (VK3) and KAT 487 (VK4) respectively. Parameters studied included physiological growth and yield aspects. The results indicated that cutting time and variety significantly affected sorghum grain and fodder yield. Variety Mexico R Line 5 produced the highest mean fodder yield of over 16 t/ha and net income of above KEs.190, 000 under C75in season 1 that had higher rainfall. KAT 487 produced the largest amount of grain up to a maximum of 2.66 t/ha and the highest net income of over KEs. 140,000 from a combination of grain and fodder underC40 in season 2 that had poorer rainfall. Sorghum harvested at 40 days after sowing produced fodder and grain within the same growing season. From the results, KAT 487 is the best sorghum variety recommended for growing as a dual purpose crop. Mexico R Line 5 is the most suited for fodder production. This study indicates that it would be possible for sorghum farmers to obtain high incomes from sorghum. It is also evident that the same crop can be harvested as fodder at 40 days after sowing and also produce grain for human consumption within the same growing season.