African stem borer resistance in early segregating genotypes of F2 sorghum population in Uganda

Abstract

Sorghum is a cereal and key food staple grain to over 500 people in semi-arid tropics Africa and Asia. The grain yield in subsistence farming ranges from 0.5 t/ha to 0.8 t/ha compared to potential yield of 10 t/ha. Low yields are attributed to biotic, abiotic and social-cultural factors. Stem borers an insect pest to sorghum causes yield losses of up to 15 - 80% due to leaf damage, death heart, exit holes and tunneling damages. Multiple control measures have been employed for stem borer management but they show some limitations. Besides, host plant resistance is an economical and effective way of controlling stem borer suitable for the resource-poor farmers. Therefore, there is need to know the resistance level among the F2 population which has been developed at NaSARRI Forty-eight (48) F2 population were sown in 8 x 6 alpha-lattice design of 3 replicates each in two sites – NaSARRI in Serere district and Busitema University Arapai campus in Soroti district. Data was collected on grain weight, plant height, 50% flowering leaf damage, dead heart, tunnel length, exit holes waxi blooms and leaf glossiness Genstat 18th version was used for data analysis where ANOVA was performed for all the observed traits. A significant different (p<0.05) was detected for all the studied parameters Some sorghum genotypes experienced low damage and registered better yields (mean 3752-3978) with genotype SILAxTanzaniaACC#42 having the highest grain yield (5720 kg/ha), followed by NAROSORG1xIS30310 (4550 kg/ha), NAROSORG1xTanzaniaACC#42 (4380) and SILAxIS12750 (3988 kg/ha). In addition, the result also revealed variation in resistance to the damage parameters across the locations and rep.