Evaluation of elite sorghum (Sorghum bicolor) varieties for resistance to field insect pests
Abstract
Sorghum [Sorghum bicolor (L.) Moench] belongs to family Poaceae. It is the fifth most
important cereal in the world’s semi-arid tropics, quantitatively the second most important cereal grain in Africa and the third most important cereal food crop in Uganda. The morphological and physiological characteristics of sorghum contribute to its adaptability to drought conditions. However, field insect pests especially Spotted stem borer (Chilo partellus) Sorghum shoot fly (Atherigona soccata), Sorghum Aphid (Melanaphis sacchari), fall armyworm (Spodoptera frugi-perda), Grasshoppers (Oedaleus senegalensis and Aliopus simulatris) and flea beetles are severe constraints to its production. The use of insect pest resistant varieties is one of the most feasible ways of managing these pests. Some sorghum varieties have been developed in the country but not enough is known about their resistance to field insect pests. A study with the overall objec-tive to generate knowledge on elite sorghum varieties that are resistant to field insect pests at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) was carried out, and the experiment was a Randomized Complete Block Design (RCBD) with four replications. The varieties SESO1, SESO3, MAKSO6 and Epuripur, which were the treatments were evaluated for one season in a field where no insecticides were added so as to determine the reaction of these varieties to the field insect pests. Data collected on pest incidence, severity as well as yield relat-ed traits, was subjected to Analysis of Variance (ANOVA) using Genstat statistical software ver-sion 14 to generate ANOVA summary which was used in testing significance. Morphological, physiological and environmental factors contributed to resistance of the varieties to the pests since the study found that the Elite sorghum varieties had severity of less than 2, which indicated that they were resistant to the field insect pests and the yield performance was on average higher than 2000kg/ha which is high compared to what the farmers obtain. It was also recommended that further studies should be done to assess resistance of these varieties in other regions of the country.