Solanum macrocarpon leaves and fruit

Taxon and scope

Kew accepts Solanum macrocarpon L. and lists Ghana in its native range. Kew also accepts S. dasyphyllum as a separate species. The 1988 Ghana flora treated S. dasyphyllum as a synonym within a highly variable S. macrocarpon complex. The Cape Coast experiment used seed collected from farmer fields or backyards and did not report a voucher that would place its accession within today’s taxonomic boundary. Its measurements therefore should not be treated as accession-confirmed results for every current taxon or cultivar.

A historical Ghana food account

Bukenya and Hall’s 1988 flora says that the S. macrocarpon complex was cultivated in Ghana mainly for its leaves, especially forms with glabrous leaves, and that the fruits were also eaten. It records an older practice of removing prickles from prickly leaves before cooking. That short historical note gives no quantities or full method, and it does not validate a safety procedure for a present-day plant or accession. The authors report the complex from almost every region of Ghana; this is their botanical account, not a current national crop survey.

What the Cape Coast experiment measured

A University of Cape Coast trial ran from February to December 2017. Researchers collected several seed accessions, then used the accession with enough seed from the same plant. The experiment used randomized blocks and measured crop response to potassium fertilizer. The published abstract says fertilizer application rate significantly affected S. macrocarpon yield. In the detailed §3.1 results, the authors report no significant rate effect on fruit fresh weight (P=0.663). The abstract and species-specific results do not agree, so the yield effect remains unresolved here. Neither statement supports a general fertilizer recommendation.

Growing conditions reported at one site

The paper describes a coastal savannah site with rainfall peaks in May–June and October, and dry harmattan months from November to February. Its soil was a haplic acrisol sandy loam with pH 6.1. Day length was reported as about 11.30 to 12.40 hours. Those figures describe the trial site and year, not species-wide requirements or limits. The paper calls the field study rain-fed, yet reports watering nursery seedlings about 50 mm daily and field irrigation of about 400 mm every 10 days when rain was absent. The wording and amounts are internally difficult to reconcile and are retained as printed, not as watering guidance. The trial does not establish frost or heat tolerance, container dimensions or greenhouse methods.

The fruit assay is not a recipe

For a potassium-retention measurement, the researchers boiled composite fruit samples for 10 minutes in 100 mL of tap water in Pyrex flasks; S. macrocarpon fruit was diced. The study measured potassium concentration before and after cooking. It did not test toxins, pathogens or a household safety endpoint, and it does not provide a complete Ghanaian dish recipe. The separate historical leaf-and-fruit account cannot fill in the missing batch quantities or steps.

Questions that remain open

No source reviewed here identifies the Cape Coast seed accession against the current S. macrocarpon and S. dasyphyllum boundary. The trial does not supply a named hardiness scheme, measured frost or heat limits, mature container or protected-crop guidance. The historical food note is not a measured recipe, and the fruit assay is not a validated preparation or storage method. The paper’s yield and irrigation reporting differences also remain unresolved.

Research gaps

The Cape Coast seed accession has no reported voucher or current taxonomic determination.

The Heliyon abstract and §3.1 differ on fertilizer-rate significance for S. macrocarpon fruit yield; the paper’s rain-fed label also sits beside printed nursery and field irrigation amounts.

No complete quantity-based household recipe, validated safety endpoint, storage method, container protocol, greenhouse method, or frost/heat tolerance was established.

Research status

The underlying plant account received a partial source review. Its review scope is described in the original plant article.