Allelopathic potential of Lantana camara for weed control in cowpea (Vigna unguiculata L. Walp)

Smallholder farmers have challenges of weed control and mostly they use cultural control methods because chemical control with herbicides is usually costly. However, Lantana camara L. is known to be allelopathic to other plants hence a worthy candidate for biological control of weeds under cowpea production. A field study was conducted to determine the potential for L. camara to control weeds in cowpea at the University of Zambia Agricultural Experimentation Station. Leaves were harvested from two genotypes of L. camara (G1: Pink-flowered and G2: Orange-flowered genotypes) dried and pulverized to form a powder and applied at different rates (R0C: 0 kg ha-1, R1: 100 kg ha-1, R2: 200 kg ha-1, R3: 400 kg ha-1) using the following types of application: T0C: No application, T1: broadcasting, T2: incorporation in the soil and T3: spraying of soaked ground L. camara. The research was conducted at the University Of Zambia School Of Agricultural Sciences Field Station. The experiment was arranged in a split split-plot design with three replications. Weed population density and weed weight were reduced the most (38% and 12.5%, respectively) at the highest rate (R3: 400 kg ha-1) of L. camara application. The cowpea grain yield was higher (P< 0.05) in fields treated with G1 (mean =876.90 kg ha-1) than for G2 (mean =672.10 kg ha-1). G1 increased cowpea grain yield by 36.04%. Lantana camara holds great potential to increase food security by reducing losses associated with weeds in cowpea.