INTRODUCTION
1.1 Background to the Study
The role of Agriculture in the development of the economy cannot be underestimated. It is important to note that with adequate and effective training in agriculture as a field of study, there will be high prospect of sustainable food security and economic advancement in the country. In order to guarantee this goal, there is need to provide top quality education services to the students particular in secondary schools. Hence, there is need for the subject to be taught thoroughly if it is to meet the educational and economic development goals.
The effect of instructional materials in promoting students’ academic performance in teaching and learning in educational development cannot be underestimated. The curriculum content of the senior secondary school levels consists of three major concepts of production, protection and economics. Learning by doing was emphasized in the curriculum so that the students should be able to produce food and other agricultural products for themselves and their community. Therefore, for effective and positive production in any establishment, there must be enough working tools to be used by the personnel (Oyedun 2000).
It is inarguable that the teacher alone cannot provide all the needed condition for an effective teaching and learning process, other supporting materials should be provided. The students learn better when most of the senses are appealed to the instruction and use of instructional materials in agriculture science education has added a new dimension in the positive promotion of the teaching and learning process. It provides the much need sensory experiences needed by the learners for an effective and meaningful behavioural change.
Instructional materials are designed to improve the quality of education for effective academic performance of agricultural science students in schools. It has been observed that teachers normally dodge the use of instructional materials in most of their teaching topics, while they try to do all they could during their practical teaching in their course of study; even though some of these materials are not usually available in the schools for teachers’ use.
Secondary schools are educational institutions below tertiary level established to inculcate in learners the societal needs and values, and make them skillful. These needs, values and teachable skills are designed into bodies of knowledge and taught to learners, such as Agricultural Science. Agricultural science is largely the application of scientific principles for successful production of crops and livestock and other uses for man’s benefit (Talathi, Naik, & Jalgaonkar, 2011; Onu, Ugwoke, Agboeze, & Ikehi, 2014).
Agricultural science, as a subject in secondary schools, seeks to teach the students the principles of using scarce resources to produce crops and animals to feed the world’s population and to service other related uses (Ikehi, Ifeanyieze, & Ugwuoke, 2014). The teaching and learning of vocational studies as well as skilled based sciences such as Agricultural Science, have often called for the use of instructional materials during content delivery to aid learners’ learning pace and retention (Onu & Ikehi, 2013).

1.2 Statement of the Problem
Several school managements have developed lackadaisical attitudes towards the provision of needed tools, equipments, and farm inputs required for effective agricultural science, especially practical in secondary schools. This negative and unconcerned attitude poses great threat to genuine efforts of some teachers of agricultural science in the secondary schools. In spite
of the emphasis being placed on agricultural science as one of the subjects in secondary schools, there is usually not enough time provided in the time-table for a meaningful agricultural science work (Adeyemi, 2000).
It has been observed that most teachers in secondary schools in the state did not fully make use of instructional materials in the teaching of agricultural science to their students. The negligence of the effective use of instructional facilities and materials in teaching and learning of agricultural science is common to both the trained and untrained teachers; this has been affecting the successful academic performance of students in agricultural science in secondary schools.
The desire to embark on this research study therefore, stemmed from the fact that there is problem of poor performance of secondary school students in agricultural science in the state. The appropriate utilization of instructional materials and teaching of agricultural science by experienced and qualified teachers, may probably be the main solution to poor performance in Agricultural Science. It was observed that students usually fail in examinations owing to improper teaching methods and lack of essential teaching aids for instructional delivery (Afolabi, 2009). This study therefore deemed it necessary to look specifically into the effect of instructional materials on academic performance of secondary school students in agricultural science.

1.3 Purpose of the Study
The main purpose of this study was to examine the effect of instructional materials on the academic performance of students in agricultural science in secondary schools in Kwara State, Nigeria.
The specific purposes were to:
1. Discover the types of instructional materials being used for teaching in order to achieve students’ academic performance in agricultural science
2. Ascertain the characteristics of instructional materials that can be used to
influence students academic performance in agricultural science
3. Evaluate the importance of using instructional materials to achieve students academic performance in agricultural science
4. Examine the factors affecting the use of instructional materials and its effect on the academic performance of students in agricultural science.

1.4 Research Questions
The following research questions were answered in the course of this study.
1. To what extent has the type of instructional materials available for use affected the academic performance of agricultural science students in secondary schools in Kwara State?
2. To what extent has the characteristic of instructional materials being used to affect the academic performance of students in agricultural science in secondary schools in Kwara State?
3. Has the importance of instructional materials affected students’ academic performance in agricultural science in secondary schools in Kwara State?
4. What are the factors affecting the use of instructional materials to influence students’ academic performance in agricultural science in secondary schools in Kwara State?

1.5 Research Hypotheses
The following null hypotheses were stated to guide the study.
Ho. There is no significant relationship between the use of available instructional
materials and students academic performance in agricultural science in
secondary schools in Kwara State.
Ho. There is no significant relationship between the use of
instructional materials and academic performance of students in
agricultural science in secondary schools in Kwara State.
Ho. There is no significant relationship between the importance of using
instructional materials and the academic performance of students in
agricultural science in secondary schools in Kwara State.
Ho. There is no significant relationship between the factors affecting the use of
instructional materials and students’ academic performance in agricultural
science in secondary schools in Kwara State.

1.6 Scope of the Study
This study is focused on examining the effect of the use of instructional materials on the academic performance in agricultural science of secondary school students in Ilorin West Local Government Area. It was carried in senior secondary school two (SSII) class public and private schools in Ilorin West Local Government Area. The students in this class were selected because they have covered some topics in SS1 and are heading to examination class. The study was delimited to thirty government and private secondary schools in Ilorin West Local Government Area of Kwara State.

1.7 Significance of the Study
The significance of this study would useful in the teaching and learning of
agricultural science. Findings from this study will also be useful in assessing the effectiveness of the stated objectives of secondary school agricultural science curriculum. It would motivate agricultural science teachers to develop interest towards utilizing suitable teaching materials that will be a possible means towards reducing failure in the teaching and learning of agricultural science.

1.8 Operational Definition of Terms
Effect: a change which is as a result of an action
Use: it is the value or advantage of something
Instructional materials: these are tools used in educational lessons which include active learning and assessment.
Performance: it is a process carrying out a task
Academic Performance: this refers to the level of grade or scores that a student obtains in class test or internal and external examination after due process of evaluation
Agricultural Science: one of the subjects offer in Junior and Senior Secondary School which focuses on the arts and science of growing crops and rearing of animals
Secondary Schools: this refers to the formal academic programmes meant for children who have completed their primary school course and are between the age of eleven to seventeen years and above.