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A survey was conducted to provide information on weed types, control strategies, and their estimated costs to smallholder rubber outgrowers in Western Ghana. A total of 80 farmers with rubber trees aged 1–4 years were randomly selected for the study. This represents 10.2% of the total number of farmers (783) who fall within this target group in the districts. The results show that smallholder rubber plantation farmers are dealing with diverse weed species, most of which are reported as global weeds. Chromolaena odorata, Scleria boivinii, and Mimosa pudica were the most reported species. Manual weeding and application of herbicides are the major control methods adopted by the farmers in the study area with a small percentage (16%) also using cover cropping. The two major control methods cost farmers an estimated average amount of Ghc 618.24 ± 26.25 (US $140.51 ± 5.91) for one-time weed control per hectare. The average estimated cost of one-time manual weeding per hectare was higher than that of herbicide application per hectare. This estimated amount is only a fraction of the total economic cost of weeds to the farmers. The farmers are likely to spend more if, for example, the costs of yield loss due to weeds are captured. The study thus indicates that the cost of weed management is high for rubber outgrowers and essentially farmers are investing heavily in weed management to keep weed competition on-plantation relatively low. Given that the core objective of rubber growing is to maximize profits, this study recommends the application of herbicides to control weeds in rubber plantations since average estimated cost of herbicide application per hectare was lower than one-time manual weeding per hectare. This recommendation should, however, be weighed against the possible environmental impact of herbicides, which was not assessed in this study.

Mistletoes are parasitic flowering plants that attack plants like cocoa and kill branches distal to point of attachment. Consequently, cocoa farmers incorporate trees to provide shade to limit germination and establishment of Tapinanthus bangwensis mistletoe species, but without success. This study was conducted in South-Western Ghana to identify causal factors of mistletoe infestation using random forest (RF) regression. Spatial arrangement of cocoa trees was the most important factor explaining mistletoe density, which was significantly higher in farms planted at random than in rows. The results imply that planting cocoa trees in rows could mitigate mistletoe infestation of Ghana's cocoa agroforests. [ABSTRACT FROM AUTHOR]

The alarming global deforestation rate has great impacts on the output of the Pulp and paper Industry since wood is the principal papermaking fiber material. Although, generally, bamboo is an alternative cellulolytic fiber source, the species and culm age have great effects on its papermaking potential. Based on the methods by the International Association of Wood Anatomists (IAWA), this work assessed the characteristics of fibers from the axial culm sections of six-month plantation-grown Oxythenantera abyssinica and Beema bamboo (which was cloned from Bambusa balcoaa) for paper production. The lengths of the fibers ranged from 1.89 to 2.39 mm while the diameters were 0.025–0.031 mm. The fiber lumen diameter and wall thickness were 0.014–0.018 mm and 0.004–0.006 mm, respectively. Fibers from the species had their runkle ratios below 1, slenderness ratios above 70 and flexibility ratios above 50. These characteristics compare well with the recommendations for fibers often used for the production of packaging, writing and printing papers. Establishment of plantations of Beema bamboo and O. abyssinica is encouraged as they will serve as good raw material base for the paper industry within six months of planting. Additionally, their planting will contribute to meeting Sustainable Development Goals 1 and 13. [ABSTRACT FROM AUTHOR]

Invasive alien species (IAS) continue to shape the global landscape through their effects on biological diversity and agricultural productivity. The effects are particularly pronounced in Sub-Saharan Africa, which has seen the arrival of many IAS in recent years. This has been attributed to porous borders, weak cross border biosecurity, and inadequate capacity to limit or stop invasions. Prediction and early detection of IAS, as well as mechanisms of containment and eradication, are needed in the fight against this global threat. Horizon scanning is an approach that enables gathering of information on risk and impact that can support IAS management. A study was conducted in Ghana to establish two ranked lists of potential invasive alien plant pest species that could be harmful to agriculture, forestry, and the environment, and to rank them according to their potential threat. The ultimate objective was to enable prioritization of actions including pest risk analysis, prevention, surveillance and contingency plans. Prioritisation was carried out using an adapted version of horizon scanning and consensus methods developed for ranking IAS worldwide. Following a horizon scan of invasive alien species not yet officially present in Ghana, a total of 110 arthropod and 64 pathogenic species were assessed through a simplified pest risk assessment. Sixteen species, of which 14 were arthropods and two pathogens, had not been recorded on the African continent at the time of assessment. The species recorded in Africa included 19 arthropod and 46 pathogenic species which were already recorded in the neighbouring countries of Burkina Faso, Côte d'Ivoire, and Togo. The majority of arthropod species were likely to arrive as contaminants on commodities, followed by a sizable number which were likely to arrive as stowaways, while some species were capable of long distance dispersal unaided. The main actions suggested for species that scored highly included full pest risk analyses and, for species recorded in neighbouring countries, surveys to determine their presence in Ghana were recommended. [ABSTRACT FROM AUTHOR]

Human-mediated seed dispersal facilitates biological invasions, including the spread of noxious and/or naturalised alien plants in Australia--but which species are dispersed by such mechanisms and what traits do they share? Data were extracted from two reviews of seed dispersed from clothing/personal equipment (e.g. backpacks) and vehicles to assess the range and types of Australian weeds benefiting from these dispersal mechanisms. Across 33 studies, including 11 from Australia, 466 species of weeds in Australia were recorded, 375 from vehicles and 212 from clothing. Many noxious species (17%) and ten Weeds of National Significance were included. Species were predominantly forbs or graminoids with few shrubs or trees. Seeds from annuals were more frequent than expected on vehicles but perennials were more frequent on clothing. New studies will add species to this corpus, but the results already highlight the importance of strategies to minimise risks from such dispersal mechanisms to help reduce the homogenisation of floras, including those in Australia. [ABSTRACT FROM AUTHOR]

Humans can unintentionally disperse plant propagules (herein referred to as seeds) including weed seeds from clothing when hiking. There is limited experimental or observational information, however, about unintended human-mediated seed dispersal, particularly from different types of clothing. We experimentally assessed the probability of seed detaching from socks and trousers along a 5 km standardized route for eight common environmental weeds: B idens pilosa L., C hloris gayana Kunth., C onyza canadensis L., C ynodon dactylon L., D rymaria cordata ( L.) Willd. ex Schult., P oa annua L., P aspalum urvillei Steud. and S porobolus elongatus R. Br. Seed detachment varied among species on both types of clothing, but seeds more easily detached from trousers than socks. When different models were fitted to the data, a three-parameter generalized exponential model with curves provided the best fit. The curves were leptokurtic, with peak close to the seed source and a long flat tail, which indicates that most seeds dispersed from clothing fall close (within 5 m) to the point of attachment with only a small proportion of seeds dispersed over long distances. Combining attachment and detachment data for the same species, we estimated the actual numbers of seeds potentially dispersed over a hike of 5 km. The study indicates that most seeds are likely to be dispersed at the start of walks, although the actual number of seeds will vary depending on several factors such as the behaviour of the hiker and the amount of weed seeds present at the start of the walk. Those few seeds dispersed much further may, however, be more important in terms of plant invasions. Covering socks with gaiters and avoiding walking through weedy areas such as road edges and car parks before starting walks could minimize the risk of seeds attaching to clothing and hence being dispersed. [ABSTRACT FROM AUTHOR]