20 Apr Investing in cassava research and development to improve productivity and reduce poverty
Tesfamicheal Wossen, Arega Alene, Tahirou Abdoulaye, Shiferaw Feleke, Ismail Rabbi, and Victor Manyong
Technological change such as the development and dissemination of improved crop varieties is understood to be the major pathway through which agricultural research brings benefits to society. Recognizing this fact, IITA, in collaboration with national and international research and development partners, have made substantial investments in developing and disseminating improved cassava varieties and complementary agronomic practices in Nigeria. However, despite these major efforts and the importance of cassava for rural livelihood, there is a lack of comprehensive and rigorous evidence on adoption rates and impacts of improved cassava varieties on productivity and poverty related outcomes to justify investment on research for crop genetic improvement.
Measuring adoption for Impact
Understanding how and why farmers adopt improved varieties and their subsequent effects on productivity and poverty is important for targeting and priority setting of technologies that are appropriate to the conditions of smallholders. IITA has successfully implemented a project entitled “Cassava monitoring survey (CMS) in Nigeria” that involved breeders, biotechnologists, bioinformaticians, economists, extensionists, agronomists, gender experts, and postharvest specialists to document adoption rates of improved cassava varieties in Nigeria, a key condition to generate an impact. The CMS project covered 16 states that together account for more than 80% of the total cassava production in Nigeria, and hence is representative at national level.
Since the evidence on the poverty reduction effects of adoption of improved cassava varieties is only as good as its measurement, we used innovative data collection approaches to overcome measurement error-related inference issues. This project also introduced a new and innovative improved cassava variety tracking system using DNA-fingerprinting approach. Traditionally, adoption and its impacts on productivity and poverty have been estimated using self-reported adoption data. However, in the presence of weak variety maintenance and dysfunctional seed certification system, measurement error in self-reported adoption data can be considerable, which leads to biased reporting of impacts on poverty reduction.
DNA fingerprinting offers a reliable method to accurately identify varieties grown by farmers and serves as a benchmark to measure the productivity and poverty reduction effects of adoption. Results from the CMS survey shows that about 60% of the farmers growing cassava have adopted improved cassava varieties. However, when adoption was measured using DNA-fingerprinting approach, it was found to be about 66%. Despite higher adoption rates, the intensification rate of improved cassava varieties was found to be about 39%, which is quite modest. Intensification rate of improved cassava varieties would have been higher if access to extension, availability of planting material as well as access to input and output markets were enhanced.
A comparison between DNA-fingerprinting and household survey adoption data further showed that 42% of the respondents misreported their adoption status. In particular, about 28% of the farmers believed that they grow local varieties when they actually grow improved varieties. Similarly, about 13% of the households believed that they grow improved varieties when they actually grow local varieties.
Measuring productivity impacts
The graph shows average cassava yield in Nigeria using self-reported and DNA-fingerprinted adoption status. The average cassava yield in Nigeria is about 14.7 t/ha, with, adopters reporting significantly higher yields than non-adopters, irrespective of the way adoption status is measured.
However, the yield difference between adopters and non-adopters is higher when adoption is measured by DNA-fingerprinting. This is so because the DNA-fingerprinting approach captures “genetic quality” more precisely. Using DNA-fingerprinted adoption data, we find that adoption of improved cassava varieties is associated with an 82% increase in cassava yields. When self-reported adoption data are used, that increase is only 60%. Thus, imprecise measurement of adoption status results in underestimation of the true productivity effects of improved cassava varieties by 18 percentage points. More accurate identification of improved varieties is key to generate robust evidence for prioritizing and justifying investment in the agricultural sector.
Impacts on poverty
How effective were productivity gains in reducing poverty? Despite large gains in productivity, the relationship between agricultural research and poverty reduction is not straightforward as benefits may not be accrued uniformly across different income groups. For example, adoption can be beneficial on average albeit ineffective in improving the income of the most vulnerable and poor farmers, who are often constrained by structural barriers that make improved technologies inaccessible and less profitable for them. Theoretically, adoption of improved cassava varieties may reduce poverty directly through productivity gains and indirectly through output, input, and labor market adjustments. By combining DNA-based adoption status with the individual- and market-level economic model, we found that adoption of improved cassava varieties contributed to reducing poverty by an estimated 4.6 percentage points, implying that 7.5 percent of the rural poor cassava producers (about 1.62 million individuals) have escaped poverty in 2015/16.
The poverty reduction impact of adoption would have been underestimated by 40% had we used traditional survey approaches instead of DNA fingerprinting. This suggests that more precise tracking of improved varieties is crucial to prioritize interventions and funding research in the agricultural sector. Further, we also found that adoption of improved cassava varieties has a heterogeneous impact. In particular, farmers who are more likely to be adopters are also likely to face higher input costs. Addressing structural and technical barriers that make adoption expensive for these groups of farmers is, therefore, important to maximize the poverty reduction effects of improved cassava varieties in Nigeria.