Compatibility of Bio and Natural Compounds with Trichogramma evanescens (Westwood) for Pieris rapae Management in Cauliflower

Abstract

The efficacy of a bio compound, Protecto (Bacillus thuringiensis) and botanicals extract (mixture of ginger, garlic, hot red pepper extracts and aloe vera) either in combination with Trichogramma  evanescens releases or alone was evaluated in comparison to an insecticide, Uphold 36% SC (Methoxyfenozide/ Spinetoram) on Pieris rapae on cauliflower Brassica oleracea. Field experiments were conducted at Atfih District, Giza Governorate, Egypt in September 2020 and October 2021. Results revealed that, all the tested compounds combined with Trichogramma releases were more effective in reducing P. rapae population than when used alone. B. thuringiensis with Trichogramma releases caused 96.91% and 95.32% reduction in larval population in 2020 and 2021 respectively while the reduction in Pieris pupal pupation was 70.87% and 71.59% respectively during these two trials. Similar results were observed with botanical extracts. Parasitization by T. evanescens ranged between 91.95-92.77% in the plots sprayed with bio- and natural compounds during the trials in two years. Meanwhile, the insecticide treatment was the least effective in reducing P. rapae population (37.85% and 47.85% respectively). It could be concluded that either B. thuringiensis or the botanicals extract could be integrated with T. evanescens releases for the sustainable production of Cauliflower.