ABSTRACT

With a view to find out the comparative field evaluation of different approaches for controlling aphid infesting maize, a field trial was conducted in the Entomology Field Laboratory, Department of Entomology, Bangladesh Agricultural University (BAU), Mymensigh. The experiment was laid out during Rabi season of 2016-17 following the complete block design (RCBD) with three replications. Maize var. BARI Hybrid Butta-09 variety was used as experimental variety. The efficacies of eight insecticides viz. Carbofuran 5G @ 20g/L (T1), Chloropyriphos 50% + Cypermethrin 5%@ 1.2ml/L (T2), Emamectin benzoate 5 SG@ 1g/L (T3), Imidacloprid 20SL@ 0.3ml/L (T4), Abamactin 1.8EC@ 2.0ml/L (T5), Spinosad@ 0.4ml/L (T6), Imidacloprid 25% + Thiram 20%@ 0.4g/L (T7) and untreated control (T8) were used as experimental treatments. The study explored that all the tested insecticides significantly reduced the plant infestation caused by maize aphid, R. maidis and thereafter increased the grain yield of maize compared to control. However, treatment T4 (Imidacloprid 20SL@ 0.3ml/L) was found as the most effective insecticides due to ensuring the highest reduction of infested plant (80.40%), the highest plant height (212.24cm), cob length without husk (22.26cm), no. of grain cob-1 (626.44), 100 grain weight (38.05g), grain yield (10.36 t ha-1), percent increase of yield over control (51.45%) and the lowest cumulative mean of plant infestation (18.53%) in maize. The best performance of imidacloprid was due to causes block the receptor, nervous system & stomach system of aphid directly and causes disrupt the cell of the aphid’s body as imidacloprid is a contact, systemic and stomach barrier insecticides. On the other hand, control treatment showed the worst performances for above parameters. However, the performances of other insecticides ranked as T7> T2> T5> T1> T6> T3> T8. Imidacloprid 20SL@ 0.3ml/L as treatments, therefore, could be recommended to the maize grower for the effective management of R. maidi.

Key words: Maize, Rhopalosiphum maidis, insecticides, management.

Introduction

Maize (Zea mays L.) is the second important cereal crops after rice in Bangladesh (The daily star, 26thSeptember, 2016) as well as the world. It is a plant belonging to the family of grasses (Poaceae). Maize, known as corn, Bengali called as Bhutta. It is considered as a staple food in many countries of the world. In Bangladesh, the production of maize is about 2.81 MT annually in 2018-2019. About 90% of the home grown maize is feeding a burgeoning poultry and fish feed industry and rests are used as human food (Alam et al., 2019a, c). It can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. Colorful kernel of maize is used as different purpose, such as a dent, flint, waxy, flour, sweet, pop and pod corn (Alam et al., 2019c). It is also cross-pollinating but self-fertile crop, so it can be grown all year round in Bangladesh and can therefore be fitted in the gap between the main cropping seasons without affecting the major crops. But it is the matter of worried that maize production is hindered by aphid infestation. Aphid, Rhopalosiphum maidis is a major agricultural pest and polyphagous attacking more than 182 plant species (Alam et al., 2014). The larvae of aphid feed on all parts of plant. This damage prevents pollination and introduces various fungi into the cobs
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