Effects of time of nitrogen application and frequency of weeding on the performance of okra (&lt;i&gt;Abelmoschus esculentus&lt;/i&gt;) in southwestern Nigeria

B Osundare

doi:10.4314/gjass.v8i1.48522

Abstract

A two – year field experiment was carried out at the Teaching and Research Farm of the University of Ado – Ekiti, Nigeria, during 2005 and 2006 cropping seasons to evaluate the effects of time of nitrogen application, frequency of weeding and the interactions between these two treatments on the growth and yield of okra. The design was a split - plot arrangement, laid out in a randomized complete block, with three replications. Nitrogen application constituted the main – plot treatment, which were: no nitrogen (control); single dose N application at four weeks after planting (WAP); split N application, with half applied at 4 WAP, and the rest at 6 WAP, and single dose N application at 8 WAP. Weeding frequency was the sub – plot factor, which comprised: no weeding (control), weeding once at 3 weeks after planting (WAP), and weeding twice at 6 and 9 WAP. The results obtained indicated that there were significant differences (P ≤0.05) between the treatments in growth and yield parameters of okra. The two – year average values indicated that time of nitrogen application significantly increased okra leaf area from 2.15m2/plant for no nitrogen (control) to 2.71, 2.49 and 2.15m2/plant for single dose N application at 4 WAP, split N application at 4 and 6 WAP, and single dose N application at 8 WAP, respectively. The main effects of weeding on okra leaf area were 2.12, 2.63 and 2.19 m2/plant for no weeding (control), weeding once (3 WAP), and weeding twice (6 and 9 WAP), respectively. Time of nitrogen application significantly increased okra fruit yield from 7.1 t ha-1 for no nitrogen (control) to 10.7, 9.1 and 7.9 t ha-1 for single dose N application at 4 WAP, split N application at 4 and 6 WAP and single dose N application at 8 WAP, respectively. Similarly, weeding significantly increased okra fruit yield from 5.9 t ha-1 for noweeding (control) to 10.5 and 7.7 t ha-1 for weeding once (3 WAP) and weeding twice (6 and 9 WAP), respectively. The interactions between time of N application and weeding frequency had significant effects on growth and yield components of okra. The treatment combination of single dose N application at 4 WAP and weeding once (3 WAP) resulted in the highest values of growth and yield parameters of okra in both years.

Highlights

Okra (Abelmoschus esculentus) is an important vegetable in Nigeria, but the yields of okra, over the years have been low because many of the okra farmers do not use fertilizers and improved methods of production (Bein, 2005)
The two – year mean values indicated that nitrogen application significantly increased okra leaf area from 2.15m2/plant for no nitrogen to 2.17, 2.49 and 2.15 m2/plant for single dose N application at 4 weeks after planting (WAP), split N application at 4 and 6 WAP and single dose N application at 8 WAP, respectively
The better performance of okra associated with single dose N application (4 WAP) and split N application (4 and 6 WAP) than single dose N application (8 WAP) agrees with the findings of Aito (2004); Demo (2005); Bako (2005); Bale (2007), who noted significantly higher values of growth and yield parameters of okra for single dose N application and split N application than those of the growth and yield indices of okra for single dose N application counterpart

Summary

INTRODUCTION

Okra (Abelmoschus esculentus) is an important vegetable in Nigeria, but the yields of okra, over the years have been low because many of the okra farmers do not use fertilizers and improved methods of production (Bein, 2005). Significant responses of okra to nitrogen application have been demonstrated by many studies (Abe, 2002; Aito, 2004; Demo, 2005; Bako, 2005; Bale, 2007) In all these studies, significant increases in growth and yield of okra on application of nitrogen fertilizers were reported. This paper reports a two – year trial, aimed at evaluating the growth and yield of okra as influenced by time of nitrogen application, weeding frequency, and the interactions between these two factors

MATERIALS AND METHODS

RESULTS

WAP 2005 2006

DISCUSSION

CONCLUSION