Growth and Yield Characteristics of Two Sweet Potato (Ipomoea batatas L.) Varieties as Influenced by Organic and Inorganic Fertilizer Application
Albert Nyarko *
Department of Science, St. Ambrose College of Education, Dormaa-Akwamu, Wamfie Bono Region, Affiliated to the University of Cape Coast, Ghana and Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Joseph Sarkodie-Addo
Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Kwadwo Adofo
CSIR – Crops Research Institute, Kumasi-Ashanti, Ghana.
Michael Odenkey Quaye
Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana and Department of Agricultural Science Education, University of Education, Winneba, Ghana.
Joseph Adu
Department of Science, St. Ambrose College of Education, Dormaa-Akwamu, Wamfie, Bono Region, Affiliated to the University of Cape Coast, Ghana.
*Author to whom correspondence should be addressed.
Abstract
A field experiment was conducted at the Crops Research Institute (CRI) at Fumesua – Kumasi from August to December, 2017. The research was to investigate the growth and yield characteristics of sweet potato (Ipomoea batatas L) to the application of organic manure (poultry manure and cow dung) and inorganic fertilizer (NPK, 15-15-15, 300kg/ha) and their combinations. The experiment was a 2x3 factorial with treatments arranged in randomized complete block design (RCBD) with three replicates. The treatments were: sole poultry manure (6t/ha); sole cow dung (8t/ha); sole NPK45-45-45kg/ha; NPK, 22.5-22.5-22.5kg/ha + Poultry manure (PM) (3t/ha); NPK, 22.5-22.5-22.5kg/ha + Cow dung(CD) (4t/ha); NPK, 33.75-33.75-33.75kg/ha + PM (1.5t/ha); NPK, 33.75-33.75-33.75kg/ha + CD (2t/ha); NPK, 7.5-7.5-7.5kg/ha +PM (4.5t/ha); NPK, 7.5-7.5-7.5kg/ha + CD (6t/ha); and no fertilizer amendment (control). Two sweet potato varieties, ‘Apomuden’ and ‘Santom Pona’ were used. The results indicated that on the average, the organic manure and the inorganic fertilizer combinations promoted greater growth than the sole applications and the control. The greatest marketable root yield (14.8 t/ha) obtained from 7.5-7.5-7.5 NPK + 4.5 t/ha PM. For root dry matter, NPK 22.5-22.5-22.5 + CD (4t/ha); NPK 22.5-22.5-22.5 + PM (3t/ha); and NPK 7.5-7.5-7.5 + CD (6t/ha) produced the greatest responses (32.6%, 31.1%, and 30.9%) respectively. Integrated application of organic manure and inorganic fertilizers is thus recommended for improved sweet potato production.
Keywords: Sweet potato, organic manure, inorganic fertilizers, integrated application, yield