A Case of Mistaken Identity? Measuring Rates of Improved Seed Adoption in Tanzania Using DNA Fingerprinting

Abstract

Studies of improved seed adoption in developing countries are almost always based on household surveys and are premised on the assumption that farmers can accurately self-report their use of improved seed varieties. However, recent studies suggest that farmers' reports of seed varieties planted, or even whether the seed is local or improved, are sometimes inconsistent with the DNA fingerprinting results of those crops. We use household survey data from Tanzania to test the alignment between farmer-reported and DNA-identified maize seed types planted. In the sample, 70% of maize seed observations are correctly reported as local or improved, while 16% are type I errors (falsely reported as improved) and 14% are type II errors (falsely reported as local). Type I errors are more likely to have been sourced from other farmers, rather than formal channels. An analysis of input use,

Distinguishing Between Nile Tilapia Strains Using a Low-Density Single-Nucleotide Polymorphism Panel

“…Corresponding assessment of returns on investment may be inaccurate, and decisions on future actions by policy makers and investors are adversely affected. Numerous tools relying on a small number of genetic markers to identify genetically homogenous inbred crop lines and clonal horticultural varieties have been developed, and the extent of seed misidentification in crops is increasingly recognized in agriculture through the application of these methods (Rabbi et al, 2015 ; Chen et al, 2016 ; Floro et al, 2018 ; Kosmowski et al, 2019 ; Wineman et al, 2020 ). However, the development of comparable tools to distinguish between strains of outcrossing aquaculture species is challenging, and information on the extent of misidentification of tilapia strains is currently limited (Baggio et al, 2016 ; Oponda et al, 2017 ; Ordoñez et al, 2017 ; Moses et al, 2020 ).…”

Methods of crop yield measurement on multi-cropped plots: Examples from Tanzania

“…Again, intercropping initially appears to be detrimental to rice yield (columns 1-2) in a statistically significant manner until we account for the space taken up by other crops. Surprisingly, the use of improved rice seed is not statistically significantly associated with yield, although Wineman et al (2019) suggest that farmers' identification of improved varieties may not always be correct.…”

Business skills training guide for potato farmer organizations and cooperatives: A guide for business skills and enterprise development

“…Error type I and Error type II are calculated based on the genotyping identification and the farmer naming of varieties. Those errors commonly occur in these types of studies as reported by Wineman et al (2020)…”