Combined effects of weed control and NPK fertilizer on yield components of kenaf (<i>Hibiscus cannabicus</i> L.)

Abstract

Two field trials were conducted during the wet season of 2017 at Zaria and Kaduna to evaluate the influence of weed control methods and NPK application on yield components of kenaf. The treatments consisted of five weed control methods, which included three pre-emergence herbicides (Pendimethalin at 2.0 kg a.i ha-1, S- Metolachor at 1.0 kg a.i ha-1 and Tank mixture of Pendimethalin, and S- Metolachor at 1.0 + 0.5kg a,i ha-1), hoe weeding at 3 and 6 weeks after sowing (WAS) and an unweeded check (control) and four levels of NPK application (0:0:0, 30:15:15, 60:30:30 and 90:45:45 kgha-1). The treatments were laid out in 5 × 4 factorial arrangements fitted into randomized complete block design (RCBD) and replicated three times. The results showed that among the weed control methods evaluated, the application of S- Metolachor at 1.0kg a.i ha-1 gave lower weed cover score, weed dry weight and higher weed control efficiency, while hoe weeding control method resulted in highest yield components. Pendimethalin at 2.0 kg a.i ha-1 , S- Metolachor at 1.0 kg a.i ha-1 and Tank mixture of Pendimethalin at 1.0 + 0.5kg a,i ha-1 gave varied weed control efficiencies with fibre yield of 845.37 kg ( 98.7%), 851.16 kg ( 97.4 %) and 531.91kg ( 61.8%) respectively at Samaru location and 638.30 kg (93,5%), 744.68 kg (83.6%) and 433.67 kg (57.6%) respectively at Kaduna location when compared to the hoe weeded control treatment with fibre yield of 866.98 kg (100%) at Samaru and 754.12 kg (100%) at Kaduna respectively. NPK application had negative influence on weed infestation but positive effect on weed control efficiency. Application of 90:45:45 kg NPK ha-1 had highest yield components. It can be concluded that, hoe weeded control treatment combined with application of NPK 90:45:45 kg ha-1 gave the best weed management that resulted to highest ribbon and fibre yield compared to all herbicides evaluated.