Open Access Journals (OAJs) development can be traced back to the 1980s when specialized press and scientific journals market collapsed due to increase in periodicals' price. The increase of price was attributed to rapid development of information and communications technologies (ICTs) which improved access to and efficiency of information dissemination globally; at the same time this increased the cost of subscription to commercial journals. Increased price affected subscription and purchasing of serials leading to uneven distribution of scientific publications. Research centers in less affluent countries were mostly hit by this decline in accessing scientific researches (Josh, Vatnal & Manjunath, 2012). In response to this challenge, the information society group innovated Open Access (OA) publishing.
Induction of Open Access Journals (OAJs) and Open Access Repository (OAR) was unavoidable since they were the main alternatives for enhancing accessibility, reputation, dissemination, possibility of citation impact and creation of knowledge-based society. Open Access Journals (OAJs) are scholarly journals that are available online to readers without financial, legal, or technical barriers other than those inseparable from gaining access to the Internet itself (Josh, Vatnal & Manjunath, 2012). OAJs are considered as important tools in enhancing visibility and impact of one's own work since Open Access articles are downloaded and cited more frequently than articles from nonAOJs (Pandita, 2013 & Kousha, 2009), and they reach broader audiences. Importantly, OAJs serve developing countries and small or specialized research institutions and corporations to have access to all Open Access articles (Ezema, 2011; Nwagwu, 2013).
Since its inception, usage of OAJs has become popular in universities and research institutes across the world including Africa, where the number of articles published in OAJs increased from 40,000 in 2004 to 260,000 in 2014 (Ware & Mobe, 2015). However, the global trend indicates unevenness in access to and usage of OAJs. Developed countries are leading in exploitation of OAJs compared to African countries, despite its existence of more than a decade. Most African countries exhibit a slow gain in usage of OAJs which hinders circulation of African publications (Nwagwu, 2013: Pandita, 2013). This paper thus examines antecedents that predict researchers' usage behavior of OAJs publishing platform for the enhancement of scholarly communication in agricultural research institutes.
Agricultural Research Institutes and OAJs in Tanzania
This study was conducted in Tanzania's Agricultural Research Institutes (ARIs) in recognition of their multiplier effects on other sectors (Ngaiza, 2012). In sub-saharan African (SSA) countries, the agriculture sector has continuously remained an engine for economic growth and the cornerstone of poverty reduction (Oyeniyi & Olaifa, 2013). It is approximated that about 65% of SSA population rely on agriculture as their primary source of livelihood, where 90% of them are categorized as small-scale farming production (Materu-Behitsa & Diyamett, 2010). In Tanzania, the agriculture sector contributes to 85% of employment, provides 85% of the country's export, 75% of foreign exchange and contributes 25.8% to the country's Growth Domestic Product (GDP) (Benard, Dulle & Ngalapa, 2014; Kapange, 2010; Ngaiza, 2012; United Republic of Tanzania, 2006).
Regarding the influence of the agricultural sector on economic growth, Tanzania government has continually increased budget for research and development (R&D) from 1.5% in 2010/2011 up to 2.5% in 2013/2014 (URT, 2014). In understanding the role of accessibility and dissemination of research findings to stakeholders, the Tanzanian government has increased ICT expenditure, waved tax for ICT facilities and its accessories (Materu-Behitsa & Diyametti, 2010; Lwezaura, 2011), increased training institutes for Information Technology (IT) (Lwezaura, 2011). However, Tanzania's efforts for the enhancement of research dissemination and accessibility can be traced back to 1986, when the government established Tanzania Commission for Science and Technology (COSTECH). COSTECH aims to strengthen dissemination of and accessibility to scientific research through harmonization of research and innovation in its website and portal (COSTECH, 1986).
Further, in 2011 Tanzania established the Consortium for Tanzania Universities and Research Libraries (COTUL) with the aim of enhancing acquisition of electronic information sources, research, training, consultancy and others deemed critical in the attainment of academic excellence in learning, teaching and research for both academic and research institutions. In safeguarding the objectives of COTUL, the policy on OA was formulated. The policy advocates open access publishing through which researchers should provide open access to their peer-review research article in order to allow archival and accessibility through OAJs and OARs. Tanzania also joined Regional Universities Forum (RUFORUM) in 2013 in order to facilitate capacity building in agriculture through knowledge sharing and exchange. Likewise, the country joined sub-regional research organizations like the Southern African Center for Cooperation in Agricultural Research (SACCAR), Eastern and Southern Africa small scale Farmers' Forum (ESAFF), Natural Resource Management (NRM), and Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA) in order to widen dissemination and accessibility to research on technologies through regional and international collaboration programme (Ngaiza, 2012; Kapange, 2010).
Despite the government's effort in facilitating accessibility and dissemination of research findings, previous studies has indicated low usage of OAJs among researchers which limits circulation. Studies by Dulle, Minish-Majanja & Cloete, 2010; Lwoga & Questier (2014; Twaakyondo, 2013) identified low attitude and lack of trust in OAJs detriment OAJs behavior. Further, study by Nwagwu (2013) highlight emergency of predatory publishers and predatory journal are among antecedents inhibiting low usage of OAJs. However, previous studies have been conducted in universities specifically on OA publishing in the African context (Dulle, Minish-Majanja & Cloete, 2010; Ezema, 2011; Nwagwu, 2013 & Pandita, 2013), there persistency low usage of OAJs in most of research institutions as well these ARIs are considered as factory for knowledge creation. As such, there are few empirical studies in Tanzania regarding researchers from non-university institutions on antecedents for usage of OAJs. It is important to note that there are different institutional cultures and characteristics (Greenfield & Rohde, 2009), and thus a deep understanding of an institution can help the global community to widen their perspective regarding the factors that influence researchers' decision toward usage of OAJs. Basing on the Theory of Reasoned Action (TRA), this study seek to establish the antecedents for usage behavior of OAJs and to investigate how these determinants can shape the researchers' intention to use OAJs in ARIs in Tanzania. Two objectives guide the study (i) to investigate the major predictors of OAJs usage of behavior among researchers from ARIs in Tanzania; and...