Phenological charts: A tool-kit in germplasm conservation and domestication of Adansonia digitata Lin in Nigeria

Abstract

Sound ex-situ conservation of parklands tree species will be appropriately complemented where detailed knowledge of the species phenological behaviours are available. Information of this type will not only provide knowledge about the plant growth, development and environment influence but also assists in the species genetic improvement. Range-wide phenological information of this type is scanty for Adansonia digitata in Nigeria. The study employed phenological review of literatures, voucher specimens examinations from a reputable herbarium in Nigeria (FHI) as well as phenological field observations for two consecutive years in the selected species range taken into consideration dry and raining season events. Data obtained were later related to their locations and their co-ordinates subsequently superimposed on the vegetation map of Nigeria, hence mapping the species into the different vegetation phytochoria or agro-ecological zones. Field phenological observations alongside with other sources of data obtained were synchronized over a 24-calendar months to produce phenological charts in the species. Findings indicated that flowering and fruiting regimes increased in a south-north direction of the species range with great overlaps. Flowering commenced late in the dry season extending northwards to the early rains (February-September) while fruiting was more of a early to mid raining season event (April-August). From the present study, future fruits collection programme should target (November“March) in the Lowland rain forest and Derived savannah range of the species and (June-September) in the Guinea and Sudan savannahs. The inconsistencies and overlaps observed in flowering and fruiting activities in the species could perhaps be attributed to global climate change and seasonality.

Key words: Adansonia digitata, phenological charts, domestication, ex-situ conservation