Gerald O. Iremiren’s research while affiliated with Cocoa Research Institute of Nigeria and other places

The chapter presents an account of tea improvement efforts in Nigeria since its introduction into the country around 1952. Commercial tea planting started in 1982. Nigeria produces black tea with the CTC method, labeled ‘Highland tea’. The total land area planted to tea is 1,200 ha. The average annual national production is 1,640 tonnes, which meets only 10% of domestic need. Opportunities thus exist for further local and foreign investments in the Nigerian tea industry. Tea improvement started in 1982 with the acquisition of 33 clones by the Cocoa Research Institute of Nigeria. Since then moderate achievements have been recorded. Five out of the 33 clones, namely 35, 68, 143, 236 and 318, with an average harvest of 2.5 tonnes/(ha· year), were selected and released to farmers. Tea clones that were adaptable to the warm lowland environment (143 and 35) and some that could be profitably intercropped with eucalyptus trees in the Nigerian environment were identified. In the tea/eucalyptus intercrop trial, the average yield from tea planted as sole-crop (2.3 tonnes/(ha· year)) was half that from the tea/eucalyptus intercrop (4.2 tonnes/(ha· year)). The eucalyptus trees stabilized the dry season tea production, enhanced the organic matter in the soil content and increased the returns per unit of farm land. Investigation into the genotypic association of the six yield components, their effects on yield and quality of the plucking, revealed tea clones whose final product after processing their leaves could generate less coarse black tea. Hybrid tea plants, which had the potential to perform better than their higher parents were generated. Currently the priority is to strengthen the Institute’s improvement program by molecular characterization of the germplasm, which would reveal accurate genetic diversity within Nigerian tea germplasm, and thus assist in selecting suitable clones as parents in a subsequent hybridization program.

An intercropping experiment involving coffee (sole), coffee/rice, coffee/plantain and coffee/ rice/plantain was carried out between 2007 and 2008 at the Cocoa Research Institute of Nigeria (CRIN) Uhonmora Substation, Edo State situated in a derived Guinea Savanna agro-ecological zone of Nigeria. The experiment was a Random-ized Complete Block Design (RCBD) with above mentioned treatment and replicated three times. The spacing used for coffee and plantain was 3 m apart respectively while rice was sown 30 cm apart. Morphological parameters such as plant height, stem girth, leaf area and canopy score were taken on coffee monthly while the survival count were taken after two months of field es-tablishment. Yields of the component crops were also collected at maturity. Data collected were subjected to statistical analysis of variance and LSD used to separate the means that were sig-nificant. Result obtained showed 98% survival without any significant difference among the treatments. On vegetative growth, coffee/rice and coffee/plantain were significantly higher (P < 0.05) than coffee sole and coffee/rice/plantain in plant girth and leaf area but not significantly higher in all the months. Plant height however did not follow the same trend as height in coffee sole was slightly higher than coffee/rice. How-ever, the difference was not significant. But coffee/plantain was still significantly higher (P < 0.05) than coffee/rice/plantain. The least was recorded in coffee/rice/plantain intercrop. Grain and bunch yields from rice and plantain respec-tively in the intercrops compare favourable well to what obtain from coffee sole. From the result obtained, it could be concluded that there was no deleterious effect on growth when rice and plantain were intercropped with coffee. There-fore coffee/rice and coffee/plantain intercropped with better performance could be recommended to coffee farmers in Nigeria rather than sole plan-ting of coffee.