Comparative Effects of Cocoa Pod Husk and Oil Palm Bunch Ash on Nutrient Uptake, Growth and Dry Matter Yield of Cocoa (The-obroma cacao) in Ibadan, Southwest Nigeria

Abstract

The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa ( T. cacao ) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7 &deg 25'N Long. 3 &deg 25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa ( T. cacao ). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg · N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in — organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.