Plant Defense Responses to Sorghum Spotted Stem Borer, Chilo partellus under Irrigated and Drought Conditions

摘要

Sorghum [Sorghum bicolor (L.) Moench] is one of the most important cereal crops in the semi-arid tropics (SAT), and insect pests are a major yield-reducing factor. Sorghum is attacked by nearly 150 insect species, causing an annual loss of over dollar1 billion in the SAT (ICRISAT 1992). A number of stem borer species have been reported as serious pests of sorghum, of which spotted stem borer, Chilo partellus Swinhoe (Lepidoptera: Pyralidae) is an important pest in India (Jotwani and Young 1972) andSouth and eastern Africa (Ingram 1958). Responses to stem borer infestation are influenced by environmental factors apart from genetic factors and their interactions. Moisture and nutrient availability influence plant growth, which in turn will influencethe extent of losses due to stem borer damage. Therefore, we studied the reaction of a diverse array of sorghum genotypes to stem borer damage under irrigated and drought conditions.