Cruciferous crops including cabbage, cauliflower, mustard, broccoli, and radish, are crucial components of winter crop production. These crops face significant threats from a range of insect pests, notably Pieris brassicae (cabbage butterfly), Plutella xylostella (diamondback moth), Brevicoryne brassicae (cabbage aphid), and Trichoplusia ni (cabbage looper). Diamondback moth (DBM), stands out as a global scourge, causing up to 80% of crucifer crop losses worldwide. Alarmingly, DBM has developed resistance to a staggering array of synthetic insecticides, rendering traditional chemical control strategies increasingly ineffective. This growing crisis necessitates a transition to environmentally friendly pest management methods, and entomopathogenic fungi (EPF) have emerged as promising solutions. EPFs, such as Beauveria bassiana, Metarhizium anisopliae, and Verticillium lecanii offer sustainable alternatives. These fungi, with their diverse insect hosts and compatibility, have demonstrated significant efficacy against lepidopteran insect pests. With approximately 750 EPF species identified over the last century, their adaptability to various ecosystems is evident. EPF possesses formidable enzymatic capabilities and produces potent toxins, making them formidable biological control agents. Once they infect an insect host, EPF exhibits vigorous vegetative growth, invading host tissues and triggering a cascade of physiological, histological, and pathological changes, ultimately resulting in the death of the host insect. The versatility of EPF, including their wide host range, environmental prevalence, enzymatic prowess, and lethal toxins, positions them as ideal candidates for sustainable and eco-friendly pest management strategies in cruciferous crop production. This review explores the potential of microbial entomopathogenic fungi, specifically B. bassiana and M. anisopliae, in addressing the challenges posed by DBM and other crucifer insect pests, shedding light on sustainable pest control methods for cruciferous crops.

Field research was conducted in the central research farm of Sher-e-Bangla Agricultural University (SAU), during the period from October 2020 to March 2021. The experiment was a layout with RCBD design to evaluate the effect of selected fungicides (Indofil, Mancer, and Ridomil Gold), micronutrients (Zinc, Boron, and Magnesium), and botanicals (neem and eucalyptus leave extract) on purple blotch complex of onion. Data were collected on percent disease incidence and percent disease index, the number of leaves per plant, leaf length, bulb diameter, bulb weight (fresh and dry), and yield. The local cultivar Faridpuri was used as a tested variety. Among the selected fungicides, Ridomil Gold gave a better result than other fungicides in controlling the percent disease incidence (52.67%) and percent disease index (49.00%) with the highest number of yield qualities per plant. In addition to this, the highest bulb diameter (18.23 cm), single bulb weight (47.98 g), fresh weight (3.16 Kg/plot), and dry weight (2.88Kg/plot) were also obtained in Ridomil Gold treated plots. This treatment also gave better yield performance (9.60 t ha-1) followed by Indofil (8.20 t ha-1) and Mancer (7.90 t ha-1), and increased yield by 54.34% over the control treatment. From the study, it was also found that among the micronutrients, boron gave more satisfactory results than botanicals.