http://hdl.handle.net/123456789/1388 2026-04-15T00:53:47Z http://hdl.handle.net/123456789/4944 Weed control in lawns in Ghana . Asiedu, J. B. K; Owusu-Sekyere, J. D.; Fiscian, P.; Afutu, E. The research investigated the effect of various regimes of herbicide application and soil treatments on weed population dynamics in three widely used tropical turfgrass species; Zoysia japonica (Carpet grass), Stenotaphrum secundatum (St. Augustine’s grass) and Chrysopogon aciculatus (Love grass). Turfgrasses were established on 5m × 1.5m plots by sprigging. Soil treatments included the following: a) plots overlaid with 3:1 topsoil/composted cow manure mix at a depth of 100 mm and b) plots with no topsoil or composted cow manure. Plots were then treated with post emergence herbicide (glyphosate) either once or twice. Non-treated plots were also included and served as the control. The research work was randomized and analyzed as unbalanced randomized complete block design. The results showed that the herbicide treatment did not reduce the quantity of germinating weeds on the plots and also there were no significant differences between the herbicide treatments. Boerhavia diffusa (Boerhavia) and Cyperus rotundus (Cyperus) were the predominant weed species. Love grass plots were invaded by higher quantity of weeds compared to the other two turfgrass species 6p:, ill. 2012-07-01T00:00:00Z http://hdl.handle.net/123456789/4943 Weed competition in maize (zea mays l.) as a function of the timing of hand-hoeing weed control in the southern guinea savanna zone of Nigeria Takim, F. O. Field studies were conducted in 2010 and 2011 at the Teaching and Research Farm of the University of Ilorin, Nigeria (9°29’ N, 4°35’ E) to evaluate the effect of early weed competition on the growth and yield of maize. The experiment was designed as a randomized complete block (RCBD) with a split-plot arrangement and three replications. The main plots consisted of three weed control treatments included weedy (no herbicide), grass weeds (pre-emergence atrazine) and broadleaf weeds (pre-emergence metolachlor), while the sub-plots consisted of six durations of weed infestation (3, 4, 5, 6, 7 and 8 weeks after emergence). The pre-emergence herbicides had a greater effect on weed density and weed dry weight. Weed seedling emergence and weed dry weight increased significantly with an increase in the duration of weed interference. The grasses and broadleaf weeds had a similar influence on the growth and grain yield of maize. Three to five weeks of weed interference gave similar grain yields, which were significantly higher than those obtained in plots that had 6–8 weeks of weed interference. These results suggest that the maize crop must be kept free of weeds for 6–8 weeks after the application of pre-emergence herbicide to minimize weed–crop competition and harvest a good grain yield 9p:, ill. 2012-07-01T00:00:00Z http://hdl.handle.net/123456789/4942 Virtual water flows under projected climate, land use and population change: the case of UK feed barley and meat Yawson, D.O.; Mohan, S.; Armah, F.A.; Ball, T.; Mulholland, B.; Adu, M.O.; White, P.J. The flow of water through food commodity trade has been rationalized in the virtual water concept. Estimates of future virtual water flows under climate, land use, and population changes could have instrumental value for policy and strategic trade decisions. This paper estimated the virtual water flows associated with feed barley and meat imports to the UK under projected climate, land use, and population changes from the 2030s to the 2050s. The results show that future virtual water inflows associated with barley imports to balance domestic deficits are larger than total volume of water used in domestic barley production in the UK. Mean virtual water associated with total UK barley production ranged from 206 to 350 million m3. This is much less than the mean total virtual water associated with barley imports (if total barley produced in the UK is used for feed), which ranged from 2.5 to 5.6 billion m3 in the 2030s to the 2050s for all land use and climate change scenarios. If domestic barley production is distributed to the different end uses, the total virtual water inflows associated with imports to balance domestic feed barley supply could be as high as 7.4 billion m3. Larger virtual water inflows (as high as 9.9 billion m3) were associated with feed barley equivalent meat imports. While the UK barley production would be entirely green, imports of either barley or meat would result in large blue water inflows to the UK. Virtual water inflows increased across the time slices for all emissions scenarios, indicating weak effectiveness of yield or productivity gains to moderate virtual water inflows. While increase in yield and land allocated to barley production should be adaptive targets, the UK needs to take policy and strategic actions to diversify trade partners and shift imports away from countries where blue water flows can exacerbate existing or potential water stresses. 11p:, ill. 2019-12-01T00:00:00Z http://hdl.handle.net/123456789/4941 Violet diode laser-induced chlorophyll fluorescence: a tool for assessing mosaic disease severity in cassava (Manihot esculenta Crantz) cultivars Anderson, Benjamin; Eghan, Moses J; Asare-Bediako, Elvis; Bassuah, Paul K Buah Violet diodelaser-induced chlorophyll fluorescence was used in agronomical assessment (disease severity and average yield per plant). Because cassava (Manihot esculenta Crantz) is of economic importance, improved cultivars with various levels of affinity for cassava mosaic disease were investigated. Fluorescence data correlated with cassava mosaic disease severity levels and with the average yield per plant 7p:, ill. 2011-03-01T00:00:00Z