Economic analysis of farmers’ preferences for cassava variety traits: implications for breeding and technology adoption in Ghana

Cassava, the most widely used food crop in Ghana, has received increased research attention mainly in the aspects of development of improved varieties. Since 1993, the National Agricultural Research System has officially released 18 improved cassava varieties which are high yielding, disease and pest resistant and early maturing. However, adoption of these varieties by mainly smallholder farmers is very low leading to low outputs and low incomes. Adoption could be improved with greater understanding of farmers’ cassava variety attributes preferences. The purpose of this study was therefore to contribute to the development and adoption of improved cassava varieties by assessing the preferences of farmers for cassava variety traits. The study explored Ghanaian cassava producers’ decision-making behaviour towards variety selection and the values they place on different cassava traits. The study applied the choice experiment technique to estimate the utility farmers derive from five cassava traits including purchase price, productivity, disease resistance, in-soil storage (matured root longevity in the soil) and multiple usage (ability to be used for different food preparations). The empirical analysis of farmers’ preferences for these traits was based on primary data collected from 450 cassava growing farmers in the Atwima Nwabiagya District of the Ashanti Region, Techiman Municipal Area in the Brong Ahafo Region and Fanteakwa District of the Eastern Region. Conditional, mixed logit and latent class models were employed to model preference behaviour for cassava traits from the choice experiment data with a focus on heterogeneity among cassava producers. The conditional logit model was employed to assess cassava traits preferences while the mixed logit model and latent class models were employed to investigate existence of preference heterogeneity and sources of heterogeneity respectively amongst cassava producers. Further analyses of farmers’ perceptions of variety traits and adoption of cassava varieties were carried out using logit and multinomial logit models in order to identify the role of trait perception on adoption of improved cassava varieties. Conditional logit and mixed logit estimates of farmers’ preferences for cassava variety traits revealed a higher preference for the in-soil storage and disease resistance traits of cassava. The willingness to pay estimates from the mixed logit also showed high willingness to pay for the in-soil storage trait in all the Districts. Farmers were willing to iv pay ₵127.68, ₵69.83 and ₵35.50 for a year or more increase in the in-soil storage trait at Atwima Nwabiagya District, Techiman Municipal and Fanteakwa District respectively. Farmers were willing to pay ₵12.85, ₵37.49 and ₵33.70 for an increase in resistance to cassava mosaic virus disease (CMVD) trait respectively at Atwima Nwabiagya District, Techiman Municipal Area and Fanteakwa District. The findings are particularly interesting because traditional cassava breeding programs often focus on high yielding and disease resistance traits, with little or no emphasis on the non-income production trait like in-soil storage. Socio-demographic factors that influenced farmers’ preferences were gender, age, experience, farm size and household size. There were significant differences between males and females, as well as between the aged and the young concerning the choice of cassava traits. The latent class model results revealed that farmer preferences were clustered around the socioeconomic parameters. Males and younger farmers mostly preferred in-soil storage and multiple usage traits. Also those with smaller land sizes preferred productivity and disease resistant traits. The logit and the multinomial logit estimates of factors that influence adoption of improved cassava varieties revealed that trait perception plays a role in the probability of adoption of improved varieties. The logit estimates results showed that hired labour, farm size, awareness, participation in cassava field day/demonstration and trait perceptions such as high resistance to diseases and pest and high in-soil storage are positive and statistically significant. The multinomial logit estimation results showed joint effect of disease resistance and in-soil storage on adoption of two improved varieties, Abasafitaa and Afisiafi. These results make a convincing case for increased field schools and demonstrations to reduce information asymmetry and to increase adoption. Higher yield, a major focus of recent research, has no effect on farmers’ adoption decisions. Farmers would not see the need to adopt more productive cassava varieties when constraints to marketing are not alleviated. Government and private sector intervention should therefore emphasize improving markets and value chains. The need for the national agricultural research systems to focus on other traits in addition to high yielding and disease resistance in order to boost adoption and increase cassava production is imperative.

Source: KNUST