Farmers’ perception about quality of planted seed yam and their preferences for certified seed yam in Ghana

The study examined the effect of farmers’ perception about the quality of seed yam typically used for cultivation on their preferences for certified seed yam. Heckman’s sample selectivity probit model was applied on survey data collected from 380 yam farmers. The study found that farmers generally agree that the use of certified seed yam would help to improve yield because of minimum to no disease/pest infestation. Farmers expressed their willingness to purchase certified seed yam if the price is about 26% higher than those supplied from the informal system in as much as the quality can be assured. The study found that farmer educational level, experience, access to extension services and household incomes were factors influencing farmers’ perception about quality of seed yam cultivated. Variables such as age, educational level and income were also found to be factors that influence farmers’ preference for certified seed yam. The results were similar for both Pona and other white yam varieties. The study recommends promotion of farmer education through increased access to extension services on seed quality assessment together with other agronomic practices including farmer field schools, to help improve their ability to assess the quality of seed yam obtained from other sources as well as increase their preference for certified seed yam

A latent class modelling approach to evaluating farmers’ preferences for pona seed yam certification systems and their willingness to pay in Ghana

The study employed choice experiment and latent class model to assess farmers’ preferences for seed yam certification system and their willingness to pay for certified seed yam in selected yam producing Districts in Ghana. A total of 9120 choice experiments were conducted to elicit data from 380 yam farmers. The study identified three classes/ market segments of farmers regarding preferences for Pona seed yam. The results show that farmers have more utility towards fully certified seed yam and are willing to pay GH¢719.60 (US$189.4) for a bunch (100 tubers weighing about 45kg) of fully certified seed yam. However, farmers were found to have high utility towards medium-sized Pona seed yam and are willing to pay a premium of GHC¢12.5 (US$3.3) for this attribute. The study has demonstrated high potential for the commercialization of seed yam production in Ghana through a formal seed yam certification system

Chromogenic detection of yam mosaic virus by closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP)

A closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP) assay was developed for the detection of yam mosaic virus (YMV, genus Potyvirus) infecting yam (Dioscorea spp.). The assay uses a set of six oligonucleotide primers targeting the YMV coat protein region, and the amplification products in YMV-positive samples are visualized by chromogenic detection with SYBR Green I dye. The CT-RT-LAMP assay detected YMV in leaf and tuber tissues of infected plants. The assay is 100 times more sensitive in detecting YMV than standard RT-PCR, while maintaining the same specificity

Economic impacts of yam productivity research in West Africa: A case of YIIFSWA Project

A bold step to addressing myriads of constraints affecting yam productivity was achieved through Yam for Income and Food Security in West Africa (YIIFSWA) project. The project has embarked on a series of activities culminating in the development, deployment and disseminating intervention options/technologies in Nigeria and Ghana. This paper assesses the potential economic impacts, the number of beneficiaries and poverty reduction through these agricultural technologies/intervention options. The land area coverable by the technologies ranged 320,000–650,000 ha in the two countries. The land area under varieties for adaptation to environments with low soil fertility was the highest followed by resistance to nematode cultivars. The net present value (NPV) ranged $144 million–$616 million and was highest for YIIFSWA diagnostic tool and temporary immersion bioreactor. Crop management and postharvest practices option had the lowest benefit-cost ratios of 6.0 and 20.03 while the aeroponics option had the highest benefit cost ratio of about 36.90. Not less than 750, 000 would be brought out of poverty by these technologies. The technologies are expected to reach not less than 20 million households by 2037 in Nigeria and Ghana. The technologies are more responsive to change in adoption rate than change in costs. Overall, while the potential economic gains are considerable, realization of these gains depends on the efficiency and effectiveness of extension and input supply systems. Concerted extension efforts are needed to drive the use of these intervention options. Moreover, considerable technical advice would also be needed to explain how to apply the

Genotype × Environment Interaction of Mosaic Disease, Root Yields and Total Carotene Concentration of Yellow-Fleshed Cassava in Nigeria

Twenty-one yellow-fleshed cassava genotypes were evaluated over two years in five major cassava growing agroecological zones in Nigeria. The trials were established in a randomized complete block design with four replications to assess genotype performance and Genotype × Environment interaction for cassava mosaic disease (CMD), fresh and dry root yield (FYLD; DYLD), root dry matter content (DMC), and total carotene concentration (TCC). Combined analysis of variance showed significant differences (P<0.001) among genotypes (G), environment (E), and Genotype × Environment interaction (GE) for all the traits tested. For reaction to CMD, the best genotypes showing stable resistance were TMS 07/0539 and TMS 07/0628. For root yield, the best genotypes were TMS 01/1368 and TMS 07/0553. Genotype TMS 07/0593 was the best for DMC and TCC across the 10 environments. Variation among genotypes accounted for most of the Total Sum of Squares for CMD (72.1%) and TCC (34.4%). Environmental variation accounted for most of the Total Sum of Squares for FYLD (42.8%), DYLD (39.6%), and DMC (29.2%). This study revealed that TMS 07/0593 has the highest and most stable TCC, DMC with the lowest CMD severity score and appeared to be the best genotype

Environment Interaction of Mosaic Disease, Root Yields and Total Carotene Concentration of Yellow-Fleshed Cassava in Nigeria

Twenty-one yellow-fleshed cassava genotypes were evaluated over two years in five major cassava growing agroecological zones in Nigeria. The trials were established in a randomized complete block design with four replications to assess genotype performance and Genotype × Environment interaction for cassava mosaic disease (CMD), fresh and dry root yield (FYLD; DYLD), root dry matter content (DMC), and total carotene concentration (TCC). Combined analysis of variance showed significant differences (P &lt; 0.001) among genotypes (G), environment (E), and Genotype × Environment interaction (GE) for all the traits tested. For reaction to CMD, the best genotypes showing stable resistance were TMS 07/0539 and TMS 07/0628. For root yield, the best genotypes were TMS 01/1368 and TMS 07/0553. Genotype TMS 07/0593 was the best for DMC and TCC across the 10 environments. Variation among genotypes accounted for most of the Total Sum of Squares for CMD (72.1%) and TCC (34.4%). Environmental variation accounted for most of the Total Sum of Squares for FYLD (42.8%), DYLD (39.6%), and DMC (29.2%). This study revealed that TMS 07/0593 has the highest and most stable TCC, DMC with the lowest CMD severity score and appeared to be the best genotype

Yam seed system characteristics in Nigeria : Local practices, preferences, and the implications for seed system interventions

Yam is an important food and cash crop in Nigeria. The seed system is mostly farmer-based and its challenges and opportunities are not well documented. This study reports results of surveys, interviews, focus group discussions and participant observations that describe local practices characterizing yam cultivation and the farmer-based seed system in five states in Nigeria. Our findings show that ware and seed yam are dynamic and highly commercialized goods in Nigeria. There is a high demand for, and a high turn-over of, seed yam. The reasons for the high demand are the low multiplication rate and degeneration of seed yam which lead farmers to frequently acquire fresh seeds and replace varieties, investing significantly in the seed of ware yam. The study found some farmers specializing in seed yam production but less than expected for such a highly commercial crop. The market is the major source for off-farm sourced seed yam, and although completely informal, the seed yam sector is vibrant and well organized. The identification of strategically positioned farmers and traders can offer opportunities and entry points for introduction of new varieties and improved seed production techniques. Building on the existing farmer-based system is a more logical strategy than replacing it with formal structures and legislative regulation