Treatments of common bean seeds (Phaseolus vulgaris L.) with insecticides for managing bean stem maggot [Ophiomyia spp. (Tryon) (Diptera: Agromyzidae)] in SNNPR, Ethiopia

Abstract

Bean stem maggot (BSM) is one of the main threatening insect pests that cause significant bean plant mortalities and associated grain yield reductions. The field research work was conducted for three successive years (2018 - 2020) in Burji, southern Ethiopia, to decide the effects of insecticide seed treatment in reducing bean plant mortality and severity/damage caused by BSM and enhancing the grain yield of common bean. The research contained seven treatments and was arrayed in a randomized complete block design with three replicas. In 2018, the lowest seedling mortality (SM) (11.78%) and matured plant mortality (MPM) (21.89%) were registered from Diazinone-treated plots. However, it was not statistically varied from Thiram + Carbofuran (13.33% for SM and 22.22% for MPM). Bean seeds treated with Diazinon considerably reduced initial percent severity index (PSIi) by 79.79% and final percent severity index (PSIf) by 79.98%, followed by Thiram + Carbofuran with PSIi by 55.67% and PSIf by 76.98% over untreated plots. Lowest total number of larvae (TNL) (15.00 and 22.67) and pupae (TNP) (11.00 and 13.67) were noted from Diazinone and Thiram + Carbofuran, in that order. Comparable fashions for SM, MPM, PSIi, PSIf, TNL, and TNP were encountered for these insecticides in 2019 and 2020. Grain yields of 2229.37 and 2213.39 kg ha-1 (in 2018) and 2648.29 and 2503.20 kg ha-1 (in 2020) were attained from Diazinone and Thiram + Carbofuran, respectively. Monetary analysis also affirmed that Diazinone ($126,429.52 ha-1) and Thiram + Carbofuran ($122,241.67 ha-1) led to a higher monitory advantage over untreated control and other insecticides. Therefore, Diazinon and Thiram + Carbofuran, one of them as an alternative option, could be advised as a seed treatment to the growers for efficient control of BSM and optimization of grain yield.

Root Rot Disease in Association with Common Bean Stem Maggot (Ophyiomia phaseoli) and Evaluation of Insecticides for Management of Stem Maggot on Common Bean (Phaseolus vulgaris L.) at West Hararghe, Ethiopia

“…Whereas the shortest plant lengths were observed in control that plots untreated having 22.6 cm (Table 4). This nding agrees with the work reported by (Mengesha,et al, 2022) using insecticide for management of steam maggot could increase plant height, growth and yield-related parameters had positive and signi cant associations between and among themselves.…”

“…The results of the insecticides application showed signi cant differences at (P < 0.05). Bean stem maggot were reported in most of haricot bean growing areas as the major insect pest of haricot bean (Mengesha,et al, 2022).…”

“…The negative and highly signi cant r values indicate the importance of the damage caused by BSM on the grain yield and yield components of common bean. According toMengesha,et al, (2022) it also showed that positive correlations between and among growth and yield-related traits could indicate the signi cance of the parameters in determining the nal grain yield of common bean3. 4 Cost bene t AnalysisPartial budget analysis indicated that variation in net bene t and marginal rate of return was observed between and among the evaluated treatments (Table6).…”