The influence of mineral fertilizers in nutrients supplementation and qualitative calyx production of roselle (Hibiscus sabdariffa L.))

Abstract

The effect of mineral fertilizer on the potentiality towards enhancing the nutritional quality of Hibiscus sabdariffa’s calyx was investigated. The research was conducted be ween July to November, 2014 during the rainy season, at Research Farm of Kano University of Science and Technology, Wudil, Kano State. The results obtained indicated that, mineral fertilizer 100kg/ha had the higher compositions of essential elements (Na, K, Mg, Ca,), trace elements (Mn, Fe, Zn and Cu) and the proximate constituents (moisture, ash, crude protein and lipid), and then reduced the anti- nutrient content (tannin) drastically, where the F100 fertilizer recorded the least in the tannin content among other fertilizers (M 5.230> F75 4.443 > F100 4.190g/100g respectively). However, mineral fertilizer at a rate of 75kg/ha recorded highest in crude fiber, carbohydrate and calorific value (11.157%, 61.725%, and 321.023kcal respectively). This indicated that, mineral fertilizer was more proficient in influencing the calyx nutritional quality. It was however proven that, mineral fertilizer (N.P.K 15-15-15) at a rate of 100kg/ha was appropriate for the qualitative dietary calyx production.

Keywords: Calyx, Essential elements, Trace elements, Proximate composition, Calorific value