Author(s): Andualem Alemayehu Atumo
Among insect pests that damage legumes worldwide, chickpea pod borer, Helicoverpa armigera, has been identified as the most harmful. Chickpea is attacked by more than 36 species of insect pests, among these pests, the pod borer, Helicoverpa armigera is the most serious one. The objective of this study was to evaluate and select effective insecticides against chickpea pod borer insect pest damage. In order to screen insecticides which have high efficacy to control Helicoverpa armigera the trial was carried out for 2020 and 2021 at Kokate and Areka main and sub research stations. The insecticides were Diazinon 60%EC, Dimeto 40%EC, Karate 5EC*, Thiodan 35%EC*, Apron star 42 WS and susceptible chickpea variety of Habru. Design was randomized complete block with three replication. The result revealed that average number of larvae outbreak on untreated plots were higher in number (12-17) than treated plot (1-6). The statistical result of grain yield implied that significant at (p<0.5% and combined data p<0.1%) level. At 2020 Diazinon 60%EC, Karate 5EC* and Thiodan 35%EC gave 52.23%, 51.91% and 50.79% higher yield per ha-1 than untreated one . Whereas, in 2021 Thiodan 35% EC*, Karate 5EC*and Diazinon 60% EC gave 53.47%, 52.75% and 49.35% higher yield per ha-1 than unsprayed one. Hence, based on the relative efficiency of insecticides Karate 5EC > Thiodan 35% > Diazinon 60% > Apron star 42 WS >Dimetho 40%. As their relative efficiency variation yield was obtained from Karate 5EC (1422.905), Thiodan 35% (1420.892), Diazinon 60% (1373.4), Apron star 42 WS (1113.385) and Dimetho 40% (1030.475) kg/ha-1 respectively. The lowest yield was recorded from untreated (677) kg/ha-1 and all insecticides proved better as compared to untreated one. The cost benefit ratio revealed that among insecticide treated karate 5EC and Thiodan35% gave higher net benefit (33019 and 32891 (ETB) i.e. Ethiopia birr) respectively followed by Diazinon 60% (31871ETB).These indicate that Karate 5EC and Thiodan 35% have high efficiency to manage Helicoverpa armigera insect pest damage followed by Diazinon 60%. The implication for future study on time interval with spraying frequency and the biology of this insect in laboratory is important to know the accurate time of insecticide spraying.
