Asian Journal of Research and Review in Agriculture

Specialised commercial nurseries that raise vegetable transplants for sale are expanding across Nigerian production landscapes, and they are widely presented as an entry point for more productive and more sustainable vegetable systems. The evidence underpinning that expectation has not been examined critically. This review assembles and appraises the international transplant-production literature, the sub-Saharan African evidence on protected nursery structures and grafting, and the Nigerian horticultural literature, in order to establish what can and cannot be defended about the contribution of commercial nurseries to sustainable vegetable production in Nigeria. Four analytical claims emerge. First, the biological case for improved transplant quality is well established, but almost all of the controlled evidence originates from temperate or subtropical systems and from crops, substrates and Sclimates that differ substantially from Nigerian conditions, so effect sizes cannot be transferred without qualification. Second, the phytosanitary argument is asymmetrical: protected nursery structures demonstrably reduce insect pressure and improve transplant quality in East Africa, whereas the corresponding risk that centralised propagation amplifies and disseminates soil-borne and seed-borne pathogens across wide production areas has been almost entirely unexamined in West Africa. Third, the economic literature on nursery enterprises in Nigeria is thin, largely descriptive and rarely counterfactual, so claims that purchasing transplants raises farm profitability rest on inference rather than measurement. Fourth, Nigerian seed legislation defines agricultural seeds to include horticultural seedlings, yet the operational certification apparatus is organised around seed lots, leaving nursery output effectively outside routine quality assurance. Priorities for research include counterfactual evaluation of transplant purchase, systematic surveillance of pathogen movement through nursery networks, life-cycle accounting of substrate and structure use, and analysis of the regulatory instruments that would make seedling quality verifiable. Confidence in current recommendations should be treated as provisional.