Impacts of Black Soldier Fly (Hermetia illucens L.) Frass on Soil Nematode Community Structure and Plant Performance Under Field Conditions

Abstract

Plant parasitic Nematodes (PPNs) pose a substantial threat to cucumber production in developing countries where chemical nematicides are very expensive, and adds to its environmental problems. This study evaluated the impact of black soldier fly frass (BSFF), on soil nematodes population dynamics in a cucumber farm. Two cucumber varieties (Nandini 732-F1 and Market More) were grown on BSFF-amended soil and unamended soil (control) for 60 days.  Soil samples and cucumber roots were collected from the rhizospheres at the two soil types at 14 days intervals for 60 days for nematode extraction with modified Baermann’s technique. Result revealed that BSFF-amended soil exhibited higher nematode diversity and abundance compared to the control. However, roots samples from the control showed higher root infections from parasitic nematodes than those from BSFF-amended soil. Endophytic nematode abundance in the cucumber roots was lower in BSFF-amended soil compared to the unamended soil. In spite of the high soil nematode density and diversity recorded, this scenario supports the idea that BSFF-soil amendments do not eliminate nematodes multiplication however, shifts community dynamics toward ecological balance. The study reveals a buildup of higher soil nematodes diversity induced by BSFF, and a reduction in plant parasitic population.  The study highlights the edaphic-friendly impact of BSFF in soil nutrient amendment and sustainable approach to manage plant parasitic nematode in cucumber farms.