Growth Response of Cocoa (Theobroma cacao L.) Seedlings to Application of Cocoa Pod Husk-based Compost

Abstract

Aim: To study the effects of cocoa pod husk based compost: Soil mixtures on growth of cocoa (Theobroma cacao L.) seedlings. Study Design: The experiment was laid out in a Complete Randomized Design with four replications. Place and Duration of Study: The experiment was conducted at the main nursery of Cocoa Research Institute of Ghana at New Tafo - Akim (06°13’ N and 00°22’ W) in the Eastern Region of Ghana, between November, 2016 and December 2017. Methodology: Surface soil classified as Ferric Lixisols together with four compost types produced from cocoa pod husk, poultry manure and Panicum maximum was used to fill polythene bags. A Soil alone (T1) and Soil + standard foliar fertilizer (T2) with a four compost:soil mixture treatments namely T3 - 1:1 w/w, T4 - 1:2 w/w, T5 -1:3 w/w and T6 - 2:1 w/w were tested. Each of the four compost types was used for T3 to T6. Surface soil, poultry manure, compost and compost-soil mixtures were carried out using standard laboratory procedures. Mixed hybrid cocoa seedlings were raised and growth evaluated monthly. Results: Interaction effect was observed between compost types and compost-soil mixtures on dry matter yield of cocoa seedlings. Cocoa seedlings grown in T5 of compost 1 had the highest dry matter yield. Higher shoot: root ratio of cocoa seedlings were observed in compost 1. The order of desirability for the four compost types in terms of compost-soil mixtures was compost:soil (1:3 w/w) > compost:soil (1:2 w/w) > compost:soil (2:1 w/w) > compost:soil (1:1 w/w). CMPT1 will ensure more vigorous cocoa seedlings growth after transplanting and subsequently, higher establishment rate. Conclusion: The optimum mixture of compost and soil for growing cocoa seedlings under limited availability of fertile surface soil is compost 1 mixed with surface soil at the ratio of 1:3.