Growth and Yield of Sweetpotato (Ipomoea batatas [L.] Lam) as Influenced by Chicken Manure and Inorganic Fertilizers

Aims: To assess the growth, yield and yield components of two varieties of sweetpotato as influenced by chicken manure and inorganic fertilizers.

Study Design: The experimental design was a 2 x 8 factorial arranged in randomized complete block design with four replicates for both seasons.

Place and Duration of Study: Field experiments were conducted at the multipurpose crop nursery of the University of Education, Winneba, Mampong-Ashanti from September, 2011 to January, 2012 (minor season) and from April to August, 2012 (major season).

Methodology: Two sweetpotato varieties (Okumkom and Apomuden) and eight fertilizer treatments [(i) 10 t ha-1 chicken manure (CM), (ii) 30-30-30 kg/ha NPK, (iii) 15-15-15 kg/ha NPK + 5 t ha-1 CM, (iv) 30-45-45 kg/ha NPK, (v) 15-23-23 kg/ha NPK + 5 t ha-1 CM, (vi) 30-60-60 kg/ha NPK, (vii) 15-30-30 kg/ha NPK + 5 t ha-1 CM and (viii) No fertilizer (control)] were studied.

Results: Okumkom differed significantly from Apomuden in number of leaves per plant, number of branches and vine fresh weight in both seasons. Apomuden grown on 30 45-45 kg/ha NPK and 30-30-30 kg/ha NPK produced significantly higher number of marketable tubers and total tuber yield during the minor season. Tuber length and number of marketable tubers of Apomuden was significantly influenced by the application of 15 – 30 – 30 kg/ha NPK + 5 t ha-1 CM during the major season. Correlation analyses in both seasons show that the vegetative characters were significantly and positively correlated. On the other hand, number of leaves per plant was negatively correlated to the total tuber weight, marketable tuber number and marketable tuber weight.

Conclusion: Farmers are encouraged to grow Apomuden on 15-30-30 kg/ha NPK + 5 t ha-1 CM for high marketable tuber number in both seasons. For high vegetative biomass as fodder for animals farmers are to grow Okumkom in both seasons.