A greenhouse study was carried out at Cocoa Research Institute of Nigeria, Ibadan to study the effect of water stress on the four popular cocoa genotypes at the institute. F 3 Amazon, T 1 , T 7 and Amelonado were raised under different water regimes (daily, 3-day interval, 5-day interval and 7-day interval) at 100%, 50% and 25% field capacities. Data were collected on the height, leaf area, root length, stomata conductance, photosynthetic rate and water use efficiency of the plants. Results showed that plant performances showed genotypic variation in their response to water stress. Generally, there were linear and positive relationships between water level and values in both physiological and morphological responses of cocoa genotypes.

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 Randomized 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 establishment. 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 significant. 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. However, 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 respectively 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. Therefore coffee/rice and coffee/plantain intercropped with better performance could be recommended to coffee farmers in Nigeria rather than sole planting of coffee.

Tea beverage is reputed worldwide for its numerous medicinal and nutritional benefits. Hot and humid climate is a major abiotic constraint to the cultivation of tea in Southwest Nigeria. Planting tea with shade trees has been used to ameliorate the adverse effects of hot climate on tea. A field experiment was carried out in Cocoa Research Institute of Nigeria stations in Ibadan and Owena, Southwest Nigeria to evaluate the growth and seedling establishment of tea plant under plantain shade. Two tea cultivars (C143 and C318) were planted on the field under three shade regimes (two plantain planting densities [1111 plantain ha-1 and 2222 plantain ha-1] and control [zero shade]). The experiment was laid out in randomized complete block design arranged in Split-plots with four replications. Data on Number of Leaves (NL), Number of Branches (NB), Leaf Area (LA), Plant Height (PH), Stem Diameter (SD) and Survival Count (SC) were collected and analysed with ANOVA and descriptive statistics at α0.05. The results showed that cultivar 143 was significantly better than cultivar 318 in NL, NB, LA, SD and SC in Ibadan and Owena. In Ibadan, plantain density of 2222 increased NL, NB, PH, SD and LA by 24%, 58%, 69%, 89% and 180%, respectively in comparison with 1111 plantain ha-1, and by 198%, 228%, 320%, 240% and 2364%, respectively compared to zero shade. In Owena, 2222 plantain ha-1 increased NL, NB, PH, SD and LA by 17%, 7%, 27%, 8% and 55%, respectively in comparison with 1111 plantain ha-1, and by 94%, 60%, 64%, 18% and 106%, respectively compared to zero shade. Highest tea seedling SC of 79.43% and 78.69% in Ibadan and Owena, respectively was caused by 2222 plantain ha-1. In Ibadan, highest NL (20.06), NB (5.81) and SD (0.53) were recorded in C143 under 1111 plantain ha-1; while in Owena, highest NL (82.81), NB (16.56), SD (0.96) and LA (6295.84) were enhanced in C143 under 2222 plantain ha-1. In conclusion, growing tea cultivar 143 under 1111 plantain/ha and 2222 plantain/ha shade densities enhanced its growth and seedling establishment in Ibadan and Owena.

Weed incidence and biomass in tree crop plantations are mainly influenced by environmental, farm management practices and cropping systems. Manipulation of intercropping systems to improve weed management in coffee intercropped with oil palm requires a better understanding of spatial and temporal dynamics of weeds. To evaluate the effect of weed incidence and biomass in coffee intercropped with oil palm in avenue and hollow square arrangement, a study was carried out in Cocoa Research Institute of Nigeria (CRIN) in two locations. The locations are Idi-Ayunre (7˚25'N, 3˚24'E) (an alfisol) and Uhonmora (6˚5'N, 5˚50'E) (ultisol) in rainforest and derived savannah parts of Nigeria respectively. The experiment had three treatments comprising coffee sole (control), coffee with oil palm (Hollow square) arrangement and coffee with oil palm (Avenue) planting. Coffee was planted 3.0 m apart while oil palm was planted 9 m apart. Equal size of land area was used for coffee in each treatment. The experimental design was Randomized Complete Block (RCBD) with three replicates. Data on vegetative growth of coffee, weed incidence and biomass were taken at three-monthly intervals. The result showed that coffee/oil palm (Hollow Square) had the least weed incidence and biomass closely followed by coffee/oil palm (Avenue) planting. The control had the highest weed biomass which was significantly different from Hollow square and Avenue planting at P ≤ 0.05. The morphological parameters on coffee followed the same pattern but Hollow square arrangement was significantly higher than Avenue and control at P ≤ 0.05.

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