CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Cowpea (Vigna unguiculata L. Walp) is an important leguminous crop cultivated mainly for its protein-rich grains, which are used in preparing various foods such as beans, moin-moin and akara. Its leaves are also consumed as vegetables, while the harvested haulms serve as valuable livestock feed, particularly in the northern parts of Nigeria. In addition, cowpea contributes to soil fertility through its ability to fix atmospheric nitrogen. According to Adigun et al. (2020), Nigeria is the world's leading producer and consumer of cowpea. The crop therefore plays an important role in the food supply and income generation of many households, especially in northern Nigeria.

Despite its importance, cowpea production on many farmers' fields is characterised by relatively low yields. Adigun et al. (2020) identified weed infestation as one of the major factors responsible for low cowpea productivity in Nigeria and other parts of sub-Saharan Africa. Cowpea seedlings generally develop slowly during their early stages of growth, making them vulnerable to competition from weeds. These unwanted plants compete with cowpea for essential resources such as sunlight, water and soil nutrients. They may also provide shelter for pests and diseases, thereby affecting crop development and reducing grain production.

The negative effects of weeds on cowpea production can be substantial. Adeyemi et al. (2020) conducted experiments at Abeokuta to examine five weeding treatments on an extra-early-maturing cowpea variety. The treatments included plots that were not weeded, plots kept completely free of weeds, and plots weeded with a hoe at three weeks after sowing, at three and six weeks, and at three, six and nine weeks after sowing. Their findings showed that uncontrolled weed growth reduced cowpea yield by 53.10% during the early season and 49.9% during the late season when compared with the highest yields obtained from weed-free plots. The treatment involving weeding at three, six and nine weeks after sowing produced the highest grain yield during the early-season experiment. The researchers concluded that this weeding schedule, combined with the application of 15 kg P₂O₅/ha, provided effective weed control and improved grain production.

However, increasing the number of weeding operations does not always result in better crop performance. Adigun et al. (2020) investigated the influence of weeding frequency and row spacing on cowpea production in the forest–savanna transition zone. Their findings indicated that two hoe-weeding operations, carried out at three and six weeks after sowing, were sufficient to achieve optimum crop growth and grain yield under the conditions of their experiment. They also observed that carrying out an additional weeding operation did not produce further improvements in growth or yield and was therefore considered unnecessary. The study further showed that a narrower row spacing of 60 cm reduced weed density by 18–39% and weed biomass by 17–27%. It also increased grain yield by 67–109% during the early season and 24–56% during the late season when compared with wider spacings of 75 cm and 90 cm. These findings demonstrate that the most suitable weeding frequency may depend on factors such as planting arrangement, season and other crop management practices.

The frequency of weeding is also influenced by the availability of labour and the cost of production. Many small-scale farmers depend on manual methods, including hand pulling and hoe weeding. These methods can be physically demanding, time-consuming and costly, particularly when labour is hired. Farmers must therefore consider whether the expected improvement in crop performance justifies the cost of carrying out an additional weeding operation. Adeyemi et al. (2020) also highlighted the continued reliance of cowpea farmers on manual weeding. The number of times farmers weed their fields, the timing of each operation and the results they obtain may be influenced by labour availability, rainfall patterns, cropping systems and the types of weeds present.

Funtua Local Government Area is located in the southern part of Katsina State, where cowpea is cultivated by small-scale farmers, often alongside cereal crops. Weed management is therefore an important aspect of cowpea production in the area. However, the weeding practices adopted by farmers may differ according to their available resources, farming experience and production conditions. This study was consequently designed to use a structured questionnaire to examine the weeding frequencies adopted by cowpea farmers in Funtua Local Government Area and their perceptions of how these practices relate to cowpea growth and yield.

1.2 Statement of the Problem

Cowpea farmers in Funtua Local Government Area face weed-related challenges throughout the rainy season. However, the number of times they weed their farms and the periods when they carry out these operations may differ according to labour availability, financial resources and personal farming experience. Previous studies conducted in other parts of Nigeria have shown that weed infestation can reduce cowpea yield by approximately half (Adeyemi et al., 2020). Other research has indicated that two properly timed weeding operations may be sufficient to support good crop growth and yield under certain production conditions (Adigun et al., 2020). Despite these findings, there is limited information on the actual weeding frequencies used by cowpea farmers in Funtua and how they assess the results of their weed management practices.

The available studies reviewed for this research were conducted mainly at research locations in south-western Nigeria (Adeyemi et al., 2020; Adigun et al., 2020). The literature consulted did not reveal a specific survey examining weeding frequency practices and farmers' perceptions of their effects among cowpea producers in Funtua Local Government Area. Differences in rainfall, soil conditions, weed types and cropping systems may influence the performance of different weeding schedules. Consequently, findings from south-western Nigeria may not fully represent the experiences and production conditions of cowpea farmers in Katsina State.

This lack of local information creates uncertainty about the weed management practices currently adopted by farmers. Some farmers may carry out too few weeding operations, allowing weeds to compete with cowpea and potentially reduce crop growth and grain production. Others may weed more frequently than necessary, resulting in additional labour expenses and production costs without corresponding improvements in yield. Agricultural extension officers may also find it difficult to provide suitable recommendations without information about the practices and challenges experienced by farmers in the area.

The problem addressed by this study is therefore the limited availability of local information on the frequency and timing of weeding operations used by cowpea farmers in Funtua Local Government Area, their perceptions of the relationship between weeding frequency and cowpea growth and yield, and the constraints affecting their weed management decisions. The study seeks to provide this information through a structured questionnaire survey of cowpea farmers in the area.

1.3 Objectives of the Study

The main objective of this study is to assess farmers' experiences and perceptions of the relationship between different weeding frequencies and the growth and yield of cowpea in Funtua Local Government Area, Katsina State, using a structured questionnaire.

The specific objectives are to:

(i) describe the socio-economic characteristics of the farmers, including their age, sex, educational level, farming experience, farm size and sources of labour;

(ii) identify the weeding frequencies, timing and methods commonly used by farmers in cowpea production;

(iii) examine farmers' perceptions of the relationship between different weeding frequencies and cowpea growth;

(iv) examine respondents' perceptions of the relationship between different weeding frequencies and cowpea yield; and

(v) identify the challenges farmers encounter when applying different weeding frequencies and the measures they recommend for improving weed management.

1.4 Research Questions

The following research questions will guide the study and correspond with the different sections of the questionnaire:

(i) What are the socio-economic characteristics of the respondents?

(ii) What weeding frequencies, timing and methods do respondents adopt in cowpea production?

(iii) How do respondents perceive the relationship between different weeding frequencies and the growth of cowpea?

(iv) How do respondents perceive the relationship between different weeding frequencies and the yield of cowpea?

(v) What challenges do respondents encounter when applying different weeding frequencies, and what improvements do they suggest?

1.5 Research Hypotheses

The following null hypotheses will be tested at the 0.05 level of significance:

H01: There is no significant relationship between the socio-economic characteristics of respondents and the frequency of weeding they adopt.

H02: There is no significant difference in the perceived growth of cowpea among respondents who carry out different numbers of weeding operations, namely once, twice, or three or more times.

H03: There is no significant difference in the perceived yield of cowpea among respondents who carry out different numbers of weeding operations, namely once, twice, or three or more times.

1.6 Significance of the Study

The findings of this study will be beneficial to cowpea farmers in Funtua Local Government Area by providing information on the weeding practices adopted by other farmers and their experiences with different weeding frequencies. This information may help farmers compare their own practices with those of other producers and make better decisions about the timing and number of weeding operations. It may also encourage more efficient use of labour and financial resources while improving farmers' understanding of weed management in cowpea production.

Agricultural extension officers will also benefit from the findings because the study will provide local information on farmers' weed management practices, the challenges they face and their opinions about the results of different weeding schedules. This information may support the development of extension programmes and recommendations that address the actual needs of cowpea farmers in the area.

Furthermore, agencies and organisations involved in supporting cowpea production may use the findings to identify the major constraints affecting weed management among farmers. Such information could assist them in planning appropriate interventions, particularly those relating to labour availability, access to weed management support and improved production practices.

The study will also contribute to existing literature on cowpea production and weed management in northern Nigeria. It may serve as a reference for students, researchers and other individuals interested in understanding farmers' weed management practices and the factors influencing cowpea growth and yield.

1.7 Scope and Limitations of the Study

This study focuses on cowpea farmers in Funtua Local Government Area of Katsina State. It is specifically concerned with the frequency of weeding operations and farmers' perceptions of how different weeding schedules relate to cowpea growth and yield. The study covers the socio-economic characteristics of respondents, their weeding methods and schedules, their assessments of crop growth and yield, and the constraints they encounter when carrying out weeding operations.

The study does not involve direct measurement of weed density or controlled field experiments to determine the actual effects of different weeding frequencies on cowpea yield. Instead, information will be obtained through respondents' experiences and assessments of their farming practices.

Some limitations may affect the research. First, the study depends on farmers' ability to remember and accurately report their weeding activities and crop performance. Their responses may therefore be influenced by personal judgement and recall difficulties. Second, differences in rainfall and weed infestation between farming seasons may influence the experiences reported by respondents. Finally, limitations in time and financial resources may restrict the number of farmers who can participate in the survey. For these reasons, the findings should be interpreted within the context of Funtua Local Government Area and applied cautiously to other locations.

1.8 Definition of Terms

Weeding Frequency: The number of times weeds are removed or controlled in a cowpea field during a particular cropping season.

Weed: Any unwanted plant growing in a cultivated field that competes with the main crop for resources such as sunlight, water, nutrients and space.

Weeks After Sowing (WAS): The number of weeks that have passed since cowpea seeds were planted in the field.

Growth: The visible development of cowpea plants, including their vigour, branching and ability to cover the ground, as assessed by farmers in this study.

Yield: The quantity of cowpea grains harvested from a given area of farmland.

Questionnaire: A structured collection of written questions designed to obtain information from respondents for research purposes.

REFERENCES

Adeyemi, O. R., Ogunsola, K. O., Olorunmaiye, P. M., Azeez, J. O., & Hosu, D. O. (2020). Effect of phosphorus (P) rates and weeding frequency on the growth and grain yield of extra early cowpea (Vigna unguiculata L. Walp) in the forest–savanna transition agro-ecological zone of Southwest Nigeria. Journal of Agricultural Sciences (Belgrade), 65(1). https://doaj.org/article/3f353abc03354de7aebb37b655ac6fea

Adigun, J. A., Adeyemi, O. R., Daramola, O. S., & Olorunmaiye, P. M. (2020). Response of cowpea (Vigna unguiculata, L., Walp) to inter-row spacing and weed competition. Agricultura Tropica et Subtropica, 53(2). https://doi.org/10.2478/ats-2020-0008