Over the past two decades, poverty has remained high, particularly in sub-Saharan Africa (about 30% of the total population) [1
]. In the entire period, the share of people living on less than USD 1 a day in this region exceeded that in the poorest region of South Asia by about 17%. It is estimated that more than 50% of the people living in sub-Saharan Africa are employed in agriculture [1
]. Therefore, investing in agriculture could contribute significantly to reduce poverty here. Although agriculture in the past two decades has been challenged by increasing drought, market shifts, and biotic and abiotic stresses [2
], experience indicate that improved varieties can overcome these challenges, including for the case of groundnut [3
Groundnut is one of the most important annual crops in the world, rich in food nutrients with about 20% protein, 40% oil, minerals, and vitamins [3
]. It is estimated that, at the farm level, at least 23% of households in developing countries are employed in groundnut production [4
]. In some developing countries, groundnut contributes to about 25 to 60% of the small-scale farmer’s income [5
]. In Tanzania, groundnut is one of the main annual crops [4
]. It can be produced in all areas with an altitude below 1500 m and with alluvial soils [6
]. These areas are either semi-arid or arid and mostly challenged by drought, food insecurity, and poverty [6
]. The production cost of groundnut is lower than that of other annual crops, such as rice [6
]. The total production cost of groundnut ranges from 500,000 Tsh/ha to 1,000,000 Tsh/ha compared to rice, which ranges from 2,500,000 Tsh/ha to 3,250,000 Tsh/ha (USD 1 equals about 2325 Tsh) [6
]. In recent times, the country increasingly has had to cope with market shifts, drought and other biotic and abiotic stresses [2
]. To cope with these challenges and improve people’s incomes and food needs, the research institute of Tanzania released six improved groundnut varieties in the 1960s and 1990s [8
]. The results in productivity were a maximum average of 444 kg/ha, below expectations during the period [8
]. Thereafter, from 2007 to 2019, 11 more improved varieties were released, and productivity increased to an average of 745 kg/ha. This is still less than the average productivity in Africa, which is 800 kg/ha [9
Even though the new varieties were available, it was reported that about 81% of the groundnut producers still used old varieties, which are less resistant to drought and diseases (e.g., foliar disease), have low productivity and low market value [12
]. The price for certified seed varied from 2317 to 4634 Tsh/kg, which is much lower than 5000 Tsh/kg for rice [13
]. It is understood that improved varieties will create long-term benefits. The groundnut market is expanding in Tanzania, due to a rapid population growth rate of 3.1 per year, the multiple uses of groundnut, and exports of about 20,000 tons per year [14
]. Considering the promising demand forecast, it is important to understand the factors hindering farmers to use improved groundnut varieties. Unfortunately, recent literature about this subject is limited.
Research carried out on factors hindering the adoption of new technology in developing countries can be grouped into three broad categories [16
]. These categories are: (i) factors related to the characteristics of farmers, (ii) factors related to the characteristics and relative performance of the technology, and (iii) communication of the new technologies. The factors related to the characteristics of farmers include educational level, experience in the activity, age, gender, technology availability, farm size, and labour availability [16
]. The factors related to the characteristics and performance of the technology include the economic functions of the product and farmers’ perceptions of the new technology. The complexity/simplicity of the new technology, relative advantage, trialability, and observability are also important. Likewise, effective communication channels able to transfer quality information on the technology and market accessibility play important roles.
Concerning social characteristics, evidence indicate that age of the farmer negatively affects the decision to adopt improved variety, while education, farming experience, and extension contact are positive contributors [17
]. However, the literature also reported age to positively affect the adoption of new technology [18
]. An analysis of the socio-economic determinants of adoption of improved groundnut varieties in Nigeria through the probit regression method found that adoption is largely explained by age and education of household head, and household size [19
]. In Kwara State of Nigeria, a study conducted to identify factors which influence adoption, found that labour, age, education, farming experience, and sex significantly affected rice variety adoption [20
]. Other reported factors included knowledge of rice cultivation, availability of seed, existence of farmer groups, information availability about improved varieties from input dealers, extension officers, and through mobile phones [18
Other studies indicated that group effects are important for individual decisions, and that, in the particular context of agricultural innovations, farmers share information and learn from each other [20
]. Individual adoption decisions depend on the choices of others in the same social groups. Since farmers anticipate that they will share information with others, they are expected to be more likely to adopt when they know many other adopters. One factor that has not received much attention in the literature is the time of the existence of a technology, which can influence adoption at scale in an area [21
In Tanzania, a study was conducted in Tabora region to determine the factors limiting production of improved groundnut. It was found that limited extension services and labour affected production [17
]. Another Tanzanian study was conducted to analyse the gender yield gap between male and female farmers in groundnut production, computing the adoption rate by agro-ecological zones, age, and sex [12
]. These studies do not adequately capture factors such as innovation motivation, time lag, communication channels and social characteristics. In general, the scope of these studies was narrow. To provide a more in-depth analysis of adoption, the present study was carried out to identify a broad range of factors and their probability to influence decision making among a larger number of farmersusing the theory of diffusion. All the seven agro-ecologies of Tanzania were surveyed, i.e., South zone, Southern Highlands, Central Zone, Lake Zone, Nothern Highlands, Coastal Zone, and western Zone. The findings could be useful to inform the implementation of new projects, the delivery of more effective extension services and the 2025 government vision of transforming the citizens to at least middle-income earners [8
]. The study first identified the improved groundnut varieties and their preferences among farmers in Tanzania. Second, it determined the rate of adoption by type of improved groundnut varieties. Third, it analyzed the key factors influencing the adoption of improved and recently released varieties of groundnut among farmers.
To increase farm productivity, employment, food, and nutritional security, the seed of improved groundnut varieties is one of the most appropriate inputs [26
]. The use of improved seed is a critical component of agriculture and in groundnut production systems [23
]. The findings show that the production of groundnut increases as the age increases in both intervention and non-intervention districts. However, in the old age of years above 50, only a few farmers can persist in production, because it is a labour-intensive type of farming [9
]. Groundnut production employed both women and youth, who are the most neglected groups in other income-generating crops like rice and tobacco [5
]. The older females in both groups were subject to low education compared to male farmers. These results are similar to the findings in the national census where females were 7% less literate than males [14
]; this negatively affects womens decision in adopting new technologies. The majority of farmers produced groundnut on small farm sizes of less than 2 ha. These smallholder farmers cannot afford to invest in productive technologies that are easily taken up in large farming [4
]. Other authors explain that farmers who produce at large scale can benefit from economies of scale, adopt improved variety, and observe good agronomic practices [27
]. The majority of farmers was not aware that the improved groundnut varieties performed better than old groundnut varities by productivity, market, and resistance to drought and diseases. These results are consistent with previous findings in Tanzania [28
The findings showed that farmers received information four ways, namely TARI-Naliendele, neighbours, extensionists, and farmer group members. Among the four communication channels, an information through a group member was the most popular channel. These results are similar to those found in Nigeria, which determined the popular method of communicating improved varities [20
]. The authors found that a farmer hearing information from a member from his/her own group increased the adoption of improved varieties. In the study area, few (28%) of the interviewed farmers were organized into groups.
About 78% of seeds were distributed by farmer groups who were legally unable to sell beyond their districts. Seed companies with the ability to distribute seeds beyond their districts account for below 1% of the total amount of seed farmers need [6
]. The skewed dependency on farmer groups channel impedes the sustainable and timely distribution of improved seeds within farming communities. These farmer groups are organized in such way that they select their farm for seed production and on-field demonstrations together. The local agricultural district officers inspect and monitor the seed production on behalf of the Tanzania Official Seed Certification Institute (TOSCI). After seed production, the group members divide the harvested seed among themselves for every individual to continue seed production on their own farm. Part of the seed is retained for continued production as a group and the remaining seed is sold to fellow farmers as a Quality Declared Seed (QDS). These farmer groups obtain their basic seeds from TARI-Naliendele, the research institute mandated for groundnut research nationwide. These farm groups select the varieties with interesting traits after promotion by TARI-Naliendele. The newer varieties are made available to farmer groups in this way. Farmers who participate in new variety trials are allowed to keep the seed for their use and informal distribution. Allowing the farmers to keep the seed from trials is observed to be one of the best ways to accelerate the adoption of improved varieties.
The findings showed that the improved groundnut varieties have higher yield compared to old varieties. Farmers produce an average of 745 kg/ha, which is way below the productivity range of improved varieties like Nachi 2015, Mnanje 2009 [11
]. The use of old varieties by farmers has been reported as one of the major causes of low productivity in smallholder farming systems [3
]. Furthermore, the limited extension service toward farmers is another cause for low productivity [26
]. The findings further showed the high market demand for recently released groundnut varieties. This corroborates previous studies that Tanzania purchases about 10% of groundnut produced in Malawi, where recent varieties are readily available [11
]. These varieties imported from Malawi are Mnanje 2009 and Nachi 2015. The information asymmetry among groundnut value chain actors partly justifies the inability of farmers to identify sources of the seed of recently released varieties [3
The findings showed that old varieties such as Pendo 1998 have higher adoption rates than recent varieties. Higher adoption rates of old varieties than the recent ones imply that the communication around new improved varieties is slow to reach the social system [21
]. In the intervention areas, old varieties, particularly Pendo 1998, were very popular, because, after release, they benefitted from intensive promotion activities in the early 2000s. However, because Pendo 1998 was highly susceptible to rosette disease, Mangaka 2009 was released in 2009, being less susceptible to rosette diseases.
It was observed that male farmers between 35 and 50 years old adopt improved groundnut varieties more than females. The results are similar to the studies that argued that male farmers can easily adopt improved groundnut varieties because they are the major household decision-makers on resource allocation [29
], and, most importantly, more exposed to technologies than the female counterpart. Indeed, societies in Tanzania are of the patrilineal type, in which the family heritage belongs to males, and the major social-economic decisions are made by males [14
]. Hence, men are in charge of decision making and can easily decide on the adoption of improved varieties. Farmers aged between 35 and 50 years were found to use more improved seeds than all other age classes. These results are contrary to the expectation since older farmers are said to be more conservative in adopting new technology. However, the study results are similar to those who noted that older farmers easily adopt improved varieties based on their vast experiences on various stresses affecting groundnut production [30
]. Tanzania has recently experienced an increasing drought due to climate changes, market changes, and biotic and abiotic stresses [2
]. This may justify the fact that older farmers can easily compare the changes through their experiences and adopt improved varieties more readily than the other age classes.
The study further showed that group membership was positive and significant as expected for improved variety adoption. It implies that as farmers join the professional farming groups, their ability to adopt improved groundnut varieties increases. The group membership ensures cohesiveness, good mandate, resources availability, integrity, access to relevant information and managerial capacity to members [31
]. This finding is similar to the observation among smallholder farmers in Malawi [32
]. In Malawi, farmers in groups were able to benefit not only from the shared knowledge among peers regarding modern farming methods, but also from economy of scale in accessing input markets as group. Hence, such farmers become good adopters of improved varieties. It was further explained that farmers who belong to an organized group usually have opportunities to access quick support from the government, NGOs, donors, and other stakeholders [33
]. In Tanzania, there are similar cases in which farmers in groups are supported with seeds from research and development organizations [3
]. Finally, seed availability and seed prices were observed significantly influence the adoption of improved groundnut varieties. Seed availability had a positive sign, whereas seed price had a negative sign, as expected. It implies that the availability of improved groundnut seeds among farmers in Tanzania at low cost increases the ability of farmers to adopt the improved groundnut varieties [34
] (pp. 34–40).
Improved groundnut varieties are an innovation worthy of being distributed throughout the country, and farmer groups can be one of the best communication channels to do so. Old groundnut varieties are less productive than improved and recently released ones. The market demand for improved varieties is higher than that of the old ones. Effective adoption of improved groundnut varieties is required to ensure sufficient supply of food and income to farmers and non-farmers. The present study analyzed factors influencing preferences and adoption of improved groundnut varieties among farmers in Tanzania. The study concluded that the overall adoption of improved groundnut varieties was still low. The factors found to influence the adoption of improved of groundnut varieties were age, gender, education, land ownership, group membership, farm size, experience, grain price, seed availability, and seed cost. The factors age, gender, group membership, and seeds availability have a significant and positive influence on farmers’ decision to adopt improved ground varieties in Tanzania. However, seed cost was significant, but negatively influencing their adoption. Based on these findings, the following measures were recommended. First, an integrated seed sector development approach, with a comprehensive strategy developed by stakeholders, would sustainably enhance access to quality seed of recently released varieties in both intervention and non-intervention areas. The promotion of the recently released varieties along with complementary agronomic practices simultaneously would incentivize farmers. Second, research, extension, and development organizations could make a difference by communicating at scale about the released groundnut varieties to all stakeholders. This will allow farmers to easily identify quality seed sources. Third, the deployment of labour-saving machinery would enable old farmers to easily manage the labour intensity to grow groundnuts and earn their living. Fourth, the enactment of good policy within the groundnut seed sector, such as comprehensive seed subsidy, will attract more seed companies to invest in groundnut seed production to ensure a wide and timely distribution of seeds. Groundnut farmers will then use improved groundnut seed, reduce abiotic and biotic stresses, and generate economic benefits. Such a policy would incentivize private businessmen and women to invest in seed and the entire commodity value chain across the country, based on the market and farmers’ demands.