Leafing, flowering and fruiting of Vitellaria paradoxa subsp. nilotica in savanna parklands in Uganda

Vitellaria paradoxa leafing, flowering and fruiting patterns were monitored in Otuke county (Lira district), northern Uganda, over a period of 25 months. The monitoring revealed that leaf shedding takes place in the middle of the dry season and the trees are in full leaf by the onset of the wet season. New leaves continue to appear on the new shoots while old leaves persist during the leaf-fall period. The pattern of leafing and leaf loss, flowering and fruiting are unimodal with major peaks in flowering and fruiting, although in the study area rainfall is bimodal. Flowering was concentrated in months when the atmospheric relative humidity begins to rise from an initially low value (around November), peaks three months later and usually ends when rainy conditions persist. Flowers produced during the rainy season usually abort. Fruiting starts at the end of the dry season (December/January) and peaks from February to April. Seed matures during the rainy season (March to May) and fruit harvesting occurs mainly from May to August, when the soil is well supplied with plant available water but coinciding with high pre-growing season famine risk in the community.