EFFECT OF SEED RATE AND PHOSPHORUS FERTILIZERS ON WEED SPECIES COMPOSITION, DENSITY, AND DIVERSITY IN SESAME VARIETIES IN SUDAN SAVANNAH OF NIGERIA

Abstract

A field experiment was conducted during the 2023 and 2024 cropping seasons in Jigawa State Sudan Savannah Zone of Nigeria to determine the effect of seed rate and phosphorus fertilizer on weed species composition, density, and diversity in sesame (Sesamum indicum L.) variety. The experiment was a factorial laid out in a randomized complete block design with three replications. Treatments consisted of three seed rates (3, 4, and 5 kg ha⁻¹), and three phosphorus levels (0, 20, and 40 kg P₂ O₅ ha⁻¹). Data were collected on weed species composition, weed density, weed dry biomass, and diversity indices. Results revealed that, higher seed rates and phosphorus fertilization significantly reduced weed density and dry biomass, while enhancing crop competitiveness. Shannon-Wiener and Simpson diversity indices decreased with increased seed rate and phosphorus application, indicating reduced weed diversity. The crop consistently suppressed weeds more effectively. The interaction between seed rate and phosphorus application significantly influenced weed composition and sesame yield. It was concluded that the application of 40 kg P₂ O₅ ha⁻¹ combined with 5 kg ha⁻¹ seed rate optimizes sesame growth while minimizing weed interference.