Submit Manuscript | http://medcraveonline.com Introduction The importance of cowpea (Vigna unguiculata L. Walp) in bridging the food gap in Nigeria cannot be overemphasized. Nutritionally, cowpea is a good source of protein for both human and livestock. It is also a source of income to farmers, serves as nitrogen fxation and cover crops thus improving the soil fertility of the marginal lands. 1 The prospect for reducing hunger, malnutrition and food insecurity through increase in cowpea productivity is signifcant. 2 In other to realise the goal, there is need to increase the output of cowpea. Among ways of achieving the goal is selection of appropriate seed input to enhance farm productivity, proftable production system and optimal return to farmers. For sustainability of smallholder farmers, increased use of inputs (seeds, chemicals and fertilizers) is of paramount importance. In sub-Saharan Africa, purchased input use is very low and static over the last 20 years or so. 3 Due to strong correlation between farmers’ output and the input utilization, there is need to improve the hybrid seed utilization of the smallholder farmers over time and there ought to exist a relationship between the input utilization of the farmer and socio–economic factors, 4 which is signifcant in the micro environment which the farmer operates. This study therefore examined the socio-economic factors infuencing the selection of seed varieties by cowpea farmers in order for research and extension to take adequate advantage of the socio-economic environment of the farmers, their cultural diversities and uniqueness in enhancing farm productivity, proftable production system and optimal return to farmers. Materials and methods The area of study is Osun State, Nigeria, and lies within latitude 7.0 0 and 9.0 0 N, and longitude 2.8 0 and 6.8 0 E. with land area of 8,602km 2 . The mean rainfall ranges from 1125mm to 1475mm while the average annual temperature ranges from 27.2 0 C to 39.0 0 C. Majority of the respondents are farmers, both food crops and permanent crops were grown either as mixed or intercropped. Random sampling technique was used to collect a sample of 200 cowpea farmers in four selected areas of Osun State, Southwestern Nigeria, for the 2013/2014 agricultural growing seasons. In each of the four purposively selected Local Governments Areas notable for cowpea production in the state, 50 cowpea farmers were selected. A structured questionnaire was used to collect information on input–output cowpea production activities. Descriptive statistics was used to describe socio-economic characteristics of the respondents while multinomial logit was used to establish relationship to likelihood of selection of cowpea seed varieties and socio-economic factors affecting it. The Multinomial Logit Model (MNLM) was used for analyzing unordered qualitative variables. It deals with truly nominal and mutually exclusive categories. Suppose a dependent variable (DV), y, has m categories that are y=1, 2 …m with P 1 , P 2 …P m as associated probabilities, such that P 1 +P 2 +…+P m =1. One value (typically the frst, the last or the value with highest frequency) of the DV is designated as the reference category. The probability of membership in other categories is then compared to the probability of membership in the reference category. Consequently, for a DV with M categories, this requires the calculation of M-1 equations, one for each category relative to the reference category, to describe the relationship between the DV and the independent variables (IVs). The generalized form of probabilities for an outcome variable with M categories is: ( ) ( ) ( ) . 2 ' exp 1 e p x m i m i i im i m m Pr y x x mx P β β = ∑ + = = = │ m > 1........ (1) Where, Pr (y i =m) is the probability of choosing either TVS variety, Oloyin, Ife Bimpe with Ife brown as the reference category. M is the number of varieties in the choice set. m = 0 is Ife brown X i is a vector of the predictor (exogenous) social factors (variables) β m is a vector of the estimated parameters For the reference category, ( ) 1 i m 2 1 1 1 exp(X , ) i i i M m Pr y x P β = = = = ∑ + │ …………….(2) for K covariates, a total of (K+1)*(M-1) parameters will be estimated. The odds and odds-ratios for a variable with M categories and Horticult Int J. 2018;2(4):141‒143. 141 ©2018 Baruwa. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Determinants of seed variety selection among cowpea farmers in Osun state, Nigeria Volume 2 Issue 4 - 2018 Baruwa Olayinka Isiaka Department of Agricultural Economics, Obafemi Awolowo University, Nigeria Correspondence: Baruwa Olayinka Isiaka, Department of Agricultural Economics, Obafemi Awolowo University, Ile Ife. Nigeria, Email aragbon2005@yahoo.co.uk Received: May 30, 2018 | Published: July 02, 2018 Abstract Appropriate seed selection enhances farm productivity, proftable production system and optimizes the cost of cultivation. The study analysed the socio-economic factors infuencing farmers’ choices of cowpea seed for cultivation in Osun State. Cross-sectional survey data of four local government areas of Osun State was obtained. Evidence from Multinomial Logit showed that years of farmer’s education, experience in cowpea farming methods, and were statistically signifcant associated with farmers’ choices relative to the reference group. The fnding indicates a need to consider farmers economic climate in seed technology development process. Key words: seed technology, adoption, cowpea, multinomial logit Horticulture International Journal Research Article Open Access