Interaction Effect of Season, Habitat and Leaf Age on Proximate Composition of Senna occidentalis and Senna obtusifolia Leaves Grown in Fadama and Upland Locations in Sokoto, Nigeria

This study was aimed to assess the effect of season, habitat and leaf age on proximate composition of leaves of Senna occidentalis L. and S. obtusifolia L. Leaves samples were collected from stands of Fadama Research Farm and Upland (Biological garden) at Permanent Site, Usmanu Danfodiyo University Sokoto and analyzed for nutrient contents using oven drying, muffle furnace ashing, soxhlet extraction, distillation and ashing, micro Kjeldahl method, and difference (NFE) methods. Data was subjected to ANOVA and LSD at 0.05% for means separation. The results for interaction effect were all statistically significant (P<0.05) in the leaves of the two Senna species and were influenced variedly by the treatment factors. Specifically, rainy subseason, fadama and upland habitats, young and matured leaves treatments favoured most of the nutrient contents (e.g. moisture, ash, crude fibre and NFE) in the following ranges : Moisture (31.37 - 81.07%), Ash (3..50 - 80.00%), Crude Fibre (1.00 – 12.50%), Ether Extract (1.07–5.47 %), Crude Protein (7.13 – 18.94 %) and NFE (60.49 - 83.66%). This indicates that season, habitat and leaf age are important factors affecting plant growth and development. The results suggest that the species may be sources of the nutrients studied and could enrich the dietary intake of individuals.Keywords: Interaction effect, Season, Habitat, Leaf age, Proximate composition, Senn