INTRODUCTION
1.1    Background to the study
The fact remains that education is the major reliable and portent for attainable growth and development in facets of human society. It is perhaps against this background that past and current education reforms in Nigeria emphasized the need to provide for every citizen. Nigeria as a developing nation seeking to become an active participant as well as a key play in the global community. Certainly must put in place, effective education system powered by a sound national policy on education. This is imperative in view of the fact that education is the bed rock of national survival, sustainable growth and development.
Teachers are the driving force in any educational system hence Teacher Education is the forum of education enterprise. Reform in education therefore, need to consider the unique roles of teachers education in the nation’s education system. Ganiyu(2008), stakeholder in Teacher Education Institutions such as College of Education and faculty of Education in University proprietors. Teacher Educator as well as trainee teacher have crucial role to play in education process.    
It is generally acknowledge that promoting teachers’ quality is a key element in improving education in Nigeria. Indeed one of the primary goals of the Nigeria Educational Policy is education for all and to attain this goal in Nigeria a highly qualified teacher is needed in every school classroom.
Teachers’ Professional development according to Yemmy (2010) is a process engaged in to enhance the knowledge, skills attitudes of the teachers. This implies the responsibility to create, preserve, evaluate and transmit knowledge through continuing education in Nigeria Learning Development programme have the ingredient of fostering and preserving the scholarly values, curiosity and integrity to nurture these values through inculcation. Chukwu (2009) states that basic aims of professional development are to improve quality of the teaching and learning as well as to improve the performances of those with teaching and management responsibilities. So the ideas for academic development can be said to conceive from the organizations acknowledgement that efficiency and effectiveness to a large extent depend on training and re-training of the work force.
The teachers’ professional development on students’ academic performances not only depends on the school environment, but also the teachers as reflected in the performances of their duties.  The teachers as well as the students are essential in the teaching and learning process. The extent to which students learning could be enhanced depends on the quality of the teachers’ handling their various subjects especially core subjects like English and Mathematics. It is believed that a qualified and competent teacher will gear up the outcomes of education that will facilitate good social political and economic emancipation, effective teaching and learning process and academic performances of the students. It is crystal clear that secondary school education is an incontrovertibly pivot of the education system of any developing nation like Nigeria. With the general awareness that the standard of academic performances achievement of secondary school students in West African Senior Secondary School Examination is falling, one wonders whether the responsibility ascribed to education as regards to nation building in not false after all. The society is much apprehensive of this observed fall in students’ academic performances in the School Certificate Examinations (SSCE) and National Examination Council (NECO). Hence, the prevalent hues and cries about the falling standard has evoked a lot of reaction and remarks form all stakeholders in education, even the National Assembly once invited the head of National Examination Council (NECO), Professor Dibu Ojerinde now the head in JAMB, to defend the poor result of students in the June/July 2009NECOExaminations.  
According to the blue print, education is that process that helps to develop individual physically, mentally, morally, socially, politically and technologically, to enable him function effectively in any environment in which he/she may find himself. The educational aim and objective to which the philosophy is linked are well documented in the policy.
Scholars continue to proffer different solution to curtail the problem of failure in Secondary Schools Education; the government only concerns itself with occasional fortification attempts. Among the various reasons advanced as the cause of poor academic performances of students at this level of education according to George (2003) education is globally accepted as the most viable tool for sustainable human development, this is why the issue of poor academic performance of students’ in Nigeria has been of much concern to the government, parents, teachers and even students themselves.
Now that various investigations of the problem have been carried out in the areas listed above, most researchers did not consider the importance of teachers as the most crucial factor next to students in any level of education. Consequently, the suggestions and recommendations of researchers are yet to achieve the desired impact. The situation persist unabated as Secondary School continue to turn out mediocre unfit for employment. This situation begets the question whether there are no other parameters influencing this phenomenon.
While the factor listed above have been well studied and most of them are almost over- flogged, the effect of teachers’ professional development on students’ academic performances as a factor of efficiency and effectiveness have received little attention from researchers in the field of education. This has therefore attracted the interest of the researcher to examine whether teachers’ professional development has any influence on students’ academic performances or not.
The aims and objectives of the National Policy on Education in Nigeria in 2016 are:
    The 6th Edition of the National Policy on Education restates Nigeria’s National goals and the philosophy of education, specifies the goals and objectives education should defines. The structure and strategies for required standards for its delivery management and for quality assurance. One of this edition highlights emphasizes improving teacher quality through professionalizing the teaching profession in Nigeria and the provision of more in-service training opportunity and other incentive for teachers.
It is therefore, understandable from the above listed National Policy on education that only a competent teacher can make it achievable.  Though the appointment and posting of teachers to schools are not within the control of the head teacher, head teachers  therefore, have to make do with the school requires, such as loading a school with social studies teachers or  religious studies teachers when is critical in need of  science teachers (Ijaiya,2012). In cases where the head teacher now uses his or her own discretion to appoint such teachers to take other subjects probably because the teacher has passed  the subject in his or her O’ Level the teacher may not render quality service expected of a competent teacher in the subject to the student. The politicization of teaching appointment and posting by government is doing a lot of harm to the educational system and can never allow the National Policy on Education to be realizable.