Optimizing sweet pepper (Capsicum annuum) productivity and phytonutrient quality using photo selective shade nets under protected cultivation in Bangladesh

An experiment was conducted on sweet pepper (Capsicum annuum L.) at the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, during October 2019-April 2020 in a two-factor randomized complete block design with three replications. Factor A comprised three net environments: white net (CN, control net environment), green net (GN, 25% shade) and black net (BN, 40% shade). Factor B comprised three cultivars: F₁ hybrid ‘Lalima’ (R), ‘Peperone Yolo Wonder’ (G) and ‘BARI Mistimorich 2’ (Y). Thirty-day old seedlings were transplanted into 10 L polyethylene bags filled with a substrate mixture of soil, vermicompost, coco dust and mushroom compost in a 20:50:20:10 (v/v) ratio and placed inside walk in tunnels. Microclimate, growth, flowering, yield and fruit quality attributes were recorded and analyzed by analysis of variance, and treatment means were separated by LSD at P ≤ 0.05. Net environment significantly affected plant growth, flowering, yield and fruit quality. GN produced the highest plant height, leaf number and leaf area, while BN resulted in inferior growth. Flowering was earliest and most profuse under GN, particularly in ‘Lalima’. The GN × ‘Lalima’ combination recorded the highest fruit yield (34.52 t ha^-1). CN maintained the highest total soluble solids and vitamin C, whereas GN enhanced antioxidant activity and anthocyanin concentration. The results indicate that a moderate shade environment created by the green net improved sweet pepper performance under protected cultivation in Bangladesh.