Yield, nutritional composition, and consumer acceptability of sweetpotato cultivars cultivated with soil amendments in the Middleveld of Eswatini

Abstract

Uncertainties about the effects of nutrient amendment on the culinary attributes of sweetpotato have limited fertiliser use in Eswatini. The study was carried out at a moist and dry location of Eswatini to investigate the culinary and nutritional attributes of sweetpotato cultivated with no amendments, cattle manure and/or inorganic fertiliser. Treatments were replicated three times in a 3 × 5 factorial arrangement using a randomised complete block design. Three sweetpotato varieties used: Ligwalagwala, Kenya White, and Lamngititi, with five nutrient amendments: no fertiliser/manure, 450 kg ha−1 NPK, 6 t ha−1 manure, 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK. Yield differences of 59.8% and 47.3% over the control were recorded with Kenya White and 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK at Malkerns and Luve, respectively. Protein, calcium, and magnesium content of the varieties improved under 4.5 t ha−1 manure + 112.5 kg ha−1 NPK amendments. Taste, flavour, palatability, and acceptability accounted for the greatest amount of culinary variability while soil amendments contributed the least. The present study suggests that nutrient amendments contribute to the agronomic performance and nutritional quality of sweetpotato.