Effect of Growth Media Nutrient Status on Cocoa (Theobroma cacao L.) Seedlings Growth and Biomass Characteristics in Abia State, Nigeria

Abstract

An experiment was conducted at the National Cereals Research Institute (NCRI), Amakama sub-station, Abia State, Nigeria to evaluate the effect of nursery media on shoot and root growth parameters and biomass of cocoa (Theobroma cacao L.) seedling from April to August 2020. The experimental design used was Completely Randomized Design (CRD) with five treatments, poultry manure plus river sand (PM + RS) at ratio of 3:2, poultry manure plus river sand plus sawdust (PM + RS + SD) at ratio of 3:1:2, poultry manure plus top soil plus river sand (PM + TS + RS) at ratio of 3:2:1, poultry manure plus top soil plus sawdust (PM + TS + SD) at ratio of 3:1:2 and Top soil (TS). Each treatment was replicated three times. The parameters measured were seedling growth parameters, shoot biomass and root biomass. At 10 WAP (weeks after planting), 12WAP and 14WAP, PM +RS + SD and PM + TS + SD recorded the highest plant heights (cm) of 30.90, 32.40, 37.45 and 29.59, 32.30, 40.38 respectively which were significantly higher (P<0.05) in values than from other media. PM + TS + SD were significantly different (P<0.05) from others but statistically same with PM + RS + SD; it had 24.33 as number of leaves at 14 WAP while others range between 13.00 and 22.33. The results showed that at 10 WAP and 14 WAP, PM + RS + SD had highest shoot fresh weight which differed significantly from those of other media. TS produced significantly the least shoot and root values at 14 WAP. It had 18.30cm as root length while others ranged from 10.37cm and 14.00cm. There was no significant difference (P<0.05) obtained at 10WAP while at 14 WAP, PM + TS + SD significantly differed from PM + RS, TS, PM + TS + RS but statistically same with PM + RS + SD on the bases of root length. PM+RS+SD was significantly different (P<0.05) from other treatments at 14 WAP for shoot and root dry matter weight. The analysis also showed a positive correlation among and between most growth parameters and plant biomass of cocoa seedling. Media PM+RS+SD and PM+TS+SD were the best in terms of growth parameters and biomass analysis of T. cacao, in the context of this work they can be recommended for raising cocoa seedlings.