Efficacy of entomopathogenic microorganisms for ecofrendly management of helicovera armigera (hub) larvae in corn crop

In the western part of Romania, Helicoverpa armigera larvae cause significant damage to several types of agricultural and horticultural crops leading to considerable economic losses, so the purpose of this paper was the use of some ecofrendly agricultural practices, namely the use of entomopathogenic microorganisms. The field experiment was conducted at the Research farm of West Land Company SRL, Jimbolia, (Timis County). The trial was laid out during 2022 vegetation season, in randomized block design with seven treatments: control plot, Bacillus sphericus + Glomus (2%) � 5 l/ ha, Metarhizium anisopliae + Glomus (2%) � 5 l/ ha, Bacillus thuringiensis var. kurstaki � 1 kg/ ha, chlorantraniliprole � 125 ml/ ha, indoxacarb � 250 ml/ ha (withdrawn from the market in 2022) and chlorantraniliprole 50 EC - 150 ml/ ha; replicated thrice having a plot size of 3042 sqm. The larval population of H. armigera was recorded before spraying and at 48 hours, 7 and 14 days after spraying. All treatments were significantly superior to control plots in reducing larval populations. Among the chemicals, percent larval reduction over control was highest at 7 days after spraying in chlorantraniliprole - 125 ml/ha plots, with an efficiency coefficient of 87.88%. Looking into the efficacy of the bioinsecticides, it was highlighted that the treatments with Bacillus thuringiensis var. kurstaki proved to be the most effective in minimizing the larval population of H. armigera in corn crop, showing an efficiency coefficient of 87.88% at 7 days, respectively 81.96% at 14 days after spraying.