A study of the floral phenology of cocoa trees was carried out between 2006 and 2008 at Kubease in the Ashanti Region of Ghana, using one hundred cocoa trees from ten farm plots. The objective was to assess the contribution of floral phenology to the productivity of cocoa. Cocoa like all tropical tree species exhibited seasonally-related phenological patterns involving overlapping cycles under both intrinsic and extrinsic controls. However, unlike most tropical plants, flowering was in the rainy season. The production of new pods or cherelles increased during the major rainy season (June, July, and August), but was evenly distributed from the minor to the dry season. Production of small and medium pods peaked in August whereas production of large pods peaked in October. There was a positive correlation between new pod production and pods abortion (r = 0.69; n = 100; P < 0.05). Temperature, light intensity, and rainfall positively affected production of floral buds and production of open flowers. However, rainfall had the greatest influence on the phenological cycle of the cocoa plant. The floral phenological pattern also coincided with the activity of the main pollinators of cocoa which resulted in enhanced reproductive capacity for increased production of cocoa.

Purpose -The purpose of this paper is to identify and assess the key factors that influence the adoption of agrochemicals on plantain farms in Ghana. Design/methodology/approach -The paper employs probit estimation using data from a stratified random sample of 249 farmers in four districts in Ghana. Findings -The results show that adoption of agrochemicals is positively associated with: being literate, older than 40 years of age, having higher income from sales, living in villages distant to Accra (capital of Ghana), having access to hi-tech machinery, being migrant, and being linked to extension services and financial institutions. Contrary to expectation, a farmer's gender and association with farmer-based organizations (FBO) and non-governmental organizations (NGO) did not make a difference. Practical implications -The results suggest that there are no exclusions to innovation systems such as agrochemical adoption based on gender or living in rural areas; women are just as technologically empowered as men, while rural farmers have an option to retain their indigenous management practices or adopt new and improved practices such as using agrochemicals. Major efforts to improve access to agrochemical adoption lie with government extension officers, as the functions of FBO and NGO have yet to make a significant difference. More needs to be done to bring young, illiterate, low income and indigene farmers into inclusive plantain science techniques and applications in Ghana. Originality/value -The paper reveals how vulnerable groups such as rural populations and women plantain farmers are being included in systems that support agrochemical adoption.

Interest in planted fallow systems has focused on soil fertility improvement, neglecting other potential benefits of such systems. It is important to quantify other processes responsible for crop yield increases under planted fallows, such as weed control. The suppressive potential on weeds of Flemingia macrophylla [(Willd.) Merrill] and Pueraria phaseoloides (Roxb.) Benth, planted fallows was evaluated in field trials in three villages in southern Cameroon. In each village, experiments were set up in 4-5 year-old bush fallow dominated by Chromolaena odorata (L.) R. M. King & H. Rob. and 20 year-old secondary forest. Total aboveground biomass production of P. phaseoloides was 7.45 Mg ha À1 , 4.2 times higher than F. macrophylla (1.78 Mg ha À1 ; P < 0.05). The high biomass of P. phaseoloides resulted in a significantly greater reduction in total weed biomass compared to Flemingia macrophylla in both wet and dry seasons. In the wet season (11 and 18 MAP), there were significant fallow system · land use and fallow system · village interactions for total weeds and broadleaf weeds. P. phaseoloides in bush (0.55 Mg ha À1 ), and P. phaseoloides at Ngoumou (0.09 Mg ha À1 ) had the lowest total weeds in the wet seasons. After the dry season, the lowest total weed mass was consistently recorded in P. phaseoloides while the highest was in the natural regrowth. The population of grasses was always higher in the F. macrophylla system than in P. phaseoloides system throughout the wet and dry seasons. Grass biomass in the P. phaseoloides-forest LUS was the least (0.01 Mg ha À1 ), 58 times lower than in F. macrophylla-bush (0.58 Mg ha À1 ). Biomass production of P. phaseoloides was highly significantly correlated with total weed biomass (r = À0.64; P = 0.004) while no relationship was found between biomass production of F. macrophylla and total weed biomass (r = À0.08, P = 0.747). It was concluded that P. phaseoloides was a suitable leguminous species for weed control. But for F. macrophylla, its low biomass production coupled with a compact plant architecture compromised it as an appropriate species for weed control in a planted fallow system.

Shea tree (Vitellaria paradoxa Gaertn. Family; Sapotaceae) indigenous to the Sudano-sahelian zone of Africa has great economic and ecological potential and attributes. Commercial cultivation of the tree is however, hampered by the poor rooting success of its planting material with adverse consequences on field establishment and total fruit yield. A 3 × 2 factorial experiment arranged in a randomized complete block design was carried out in 2012 at Bole in the Interior Savanna agro-ecological zone. The objective was to assess the rooting success of Shea shoots by the air-layering technique using two media types (palm fibre and Sphagnum moss) and three IBA hormone concentrations (0, 5000 and 10,000 ppm) under contrasting climatic (wet and dry) conditions. Layered shoots which were sprayed with 10,000 ppm IBA and wrapped with Sphagnum moss gave significantly (P < 0.05) higher rooting success in terms of more roots per cutting (73.3%) and longer roots per cutting (9.0 cm) than palm fibre at both 5000 ppm (30.0%; 3.7 cm) and 10,000 ppm (46.7%;7.9 cm) concentrations. Higher rooting success was significantly achieved in the wet season than in the dry season. Sphagnum moss treated with 10,000 ppm IBA facilitated the translocation of higher levels of sugar and total free phenol (TFP) to the base of the layered shoots which resulted in significantly (P < 0.05) higher number of roots and better roots protection from fungal infection than the other treatments. Rooting of layered shoots was affected to a greater extent by low temperatures (Rooting = 836-34.2 Temp (low); R 2 = 82%, p < 0.001) than by high temperatures (Rooting = 5250-175.0 Temp (high); R 2 = 64.5%, p < 0.009). Rooting of layered shoots was also significantly and negatively affected by the spread of the canopy of the selected tree such that closed canopy trees resulted in higher and better rooting that open canopy trees (Rooting = 113.87-23.697(Canopy spread); R 2 = 89%, p = 0.002; n = 9). Furthermore, significant J. Yeboah et al. 1213 and positive correlations were found between IBA concentration level and simple sugars (r = 0.99; P < 0.0001; n = 9) and also between IBA concentration level and total free phenols (r = 0.98; P < 0.0002; n = 9). The study concluded that to achieve high rooting success in the propagation of Shea nut tree by the air-layering technique, a combination of Sphagnum moss treated with 10,000 ppm of IBA hormone should be used and the whole set up carried out in the wet season.

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Changes in soil properties and nematode population status under Flemingia macrophylla [(Willd.) Merrill], Pueraria phaseoloides (Roxb.) Benth, and natural bush fallows were assessed in three villages in southern Cameroon. In each village, experiments were set up in a 4-5 year-old bush fallow dominated by Chromolaena odorata (L.) R. M.King and H. Rob and a more than 20 year-old secondary forest. Total aboveground biomass production of P. phaseoloides was 7.45 Mg ha -1 , 4.2 times higher than F. macrophylla (1.78 Mg ha -1 ; P \ 0.05). In two years (24 MAP), the soil bulk density under P. phaseoloides, F.macrophylla and the natural regrowth in both bush and forest land use systems decreased (P \ 0.05). Within the same period, there was a general improvement in aggregate stability. The particle size distribution changed over 3 years (36 MAP), such that at 0-10 cm depth, the percent sand content had reduced whiles the percent clay content had increased under all the fallow systems in both bush and forest land use systems (LUSs). Soil N also increased significantly (P \ 0.05) after cropping under all the fallow systems in both LUS. In contrast, soil organic carbon decreased, but the extent was lower under P. phaseoloides and F. macrophylla compared to the natural regrowth. Soil P also decreased after cropping under all the fallow systems in both LUS whereas decrease in Mg was only observed under P. phaseoloides. F. macrophylla had Mg content after cropping similar to the initial in both LUS. Soil contents of K and Ca were not significantly different over time under all the fallow systems. Comparing the initial Helicotylenchus multicinctus population to that at 12 MAP, both P. phaseoloides and F. macrophylla reduced density of H. multicinctus (P \ 0.05). However, when the initial population density was compared to that at 24 MAP only under P. phaseoloides was the reduction maintained. The study concluded that the general improvement in the soil physical properties, impacted positively on the N and organic carbon contents which were sustained to a larger extent under the planted fallows than the natural regrowth. Furthermore, P. phaseoloides could be used as one component for the biological control of Helicotylenchus multicinctus, a phytopathogenic nematode.

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