Soil Nutrient Management Practices Influence the Carotenoid Content and Profile of Orange Fleshed Sweet Potato Variety (UMUSPO 3)

Abstract

Food bio fortification holds a lot of promise for the alleviation of hidden hunger. The appropriate soil nutrient management methods that will maximize the pro vitamin A content of bio fortified Orange fleshed sweet potatoes (OFSP) (Umudike Sweet Potato Orange-fleshed 3) was evaluated in the present research. The carotenoid content and profile of OFSP variety grown on soils given five different nutrient managements were compared. The soil management treatments given were: (VB1) Poultry manure at 5 x 103 kg/ha (control); VB2: Poultry manure at 2.5 x 103 kg/ha + NPK at 200 kg/ha + Agrolyser at 2.7 kg/ha, VB3: Agrolyser at 2.7 kg/ha + NPK at 200 kg/ha; VB4: Poultry manure at 5.0 x 103 kg/ha + NPK at 200 kg/ha, VB5: NPK 15:15:15 at 400 kg/ha. (Agrolyser: Ca – 20.4%; Na – 1.04%; Zn – 0.11%, S – 2.72%; Fe, Mn, Mo trace) (NPK 15:15:15 was used in all cases). Carotenoids were extracted from the potato samples and analyzed using High performance Liquid Chromatography (HPLC). The best treatment that promoted high pro vitamin A carotenoid content was soil treatment with Poultry manure (5x 103 kg/ha+ NPK (200kg/ha). This soil treatment led to the highest contents of α-carotene (6.14μg/g); 13-cis-β-carotene (12.36μg/g); All-trans-β-carotene (87.89μg/g) and 9-cis-β-carotene (2.99μg/g). The best soil management treatment for the highest yield of β-cryptoxanthin (7.95μg/g) was poultry manure at 2.5kg/ha +NPK at 200kg/ha.