Book Chapter: Varietal and Management-Based Modulation of Pests, Diseases, Weeds, and Yield Traits in Tomato Production and Productivity

Tomato (Solanum lycopersicum L.) plays a vital nutritional and economic role in Sierra Leone; however, its production is hindered by pest infestations, disease outbreaks, weed competition, and suboptimal agronomic practices. This study assessed the impact of two tomato varieties which are Heirloom (improved) and Nornro (local) under four agronomic management practices (AMPs), combining organic and inorganic approaches, over a two-year field trial (2022-2023) at Njala University. The experiment followed a 2 × 4 factorial design in a Randomized Complete Block Design (RCBD) with three replications. AMP 1, which included chicken manure, mulching, and neem biopesticide, significantly improved plant height, branch number, truss formation, and fruit yield (up to 5.3 t/ha), outperforming both the inorganic treatment (AMP 3: 4.6 t/ha) and the control (AMP 4: 2.5 t/ha). AMP 3, involving NPK fertilizer and chemical pesticides, was most potent in reducing pest populations (whiteflies, aphids, and leaf miners), disease incidence (tomato mosaic and bacterial leaf blight), and weed infestation. Conversely, AMP 1 also effectively enhanced soil health and economic returns, producing the highest net revenue (SLL 380,000/ha). The local Nornro variety demonstrated superior pest and disease resistance, while the Heirloom variety exhibited better vegetative growth. Weed surveys revealed diverse species dominated by Poaceae and Fabaceae families, with Imperata cylindrica and Panicum maximum being most prevalent. Overall, integrated organic and inorganic practices significantly influenced tomato productivity, weed suppression, and profitability. The findings advocate for the adoption of AMP 1 as a sustainable and eco-friendly strategy for enhanced tomato cultivation in low-input agricultural systems in Sierra Leone.