EFFECT OF ROOT MAT MANAGEMENT AND PHOSPHATE FERTILIZER APPLICATION ON THE FIELD ESTABLISHMENT OF COCOA IN ONDO STATE, NIGERIA
A study was carried out to evaluate the effect of root mat management and P-fertilizer application on the field establishment of cocoa in Ondo State, Nigeria. Six treatment combinations were formed from two levels of root mat treatments (with and without root mat) and three types of phosphate fertilizer application (no P, Single Super phosphate and Sokoto Rock Phosphate). The root mat management (treatments) and phosphate fertilizer application were done during cocoa seedling transplanting. The treatments were arranged in a RCBD with three replications. The height, stem diameter, number of leaves and leaf area of the transplanted cocoa seedlings were regularly taken on a monthly basis. Seedlings with root mat intact (not removed) significantly (p < 0.05) consistently enhanced the height of cocoa seedlings at 3, 6, 9, 12, and 15 months after transplanting (MAT). Similarly, the stem diameter of cocoa seedlings at 3 MAT was significantly improved as a result of non-removal of root mat. However, the influence of root mat removal on the stem diameter of cocoa seedlings was not consistently higher than those with root mat intact at 6 and 9 MAT, it gave higher stem diameter through 12 and 15 MAT. Root mat removal did not significantly affect the number of leaves and leaf area of the cocoa seedlings throughout the period of study. P-fertilizer application did not show significant effect on the various growth parameters of cocoa seedlings throughout the period of study. Similarly, the pH, organic carbon and the level of available P accumulation of the soil were not significantly affected by phosphate fertilizers and root mat management. It can be concluded that the extra effort of removing the root mat of cocoa seedlings before transplanting and application of phosphate fertilizer did not confer any advantage in terms of growth on the transplanted cocoa seedlings on the field.