8 research outputs found
Influence of glyphosate on rhizosphere microorganisms and their ability to solubilise phosphate
Objective: To determine cowpea rhizosphere microor-ganisms with phosphate solubilizing potential in a soil treated with glyphosate. Methods: Four different con-centrations of glyphosate herbicides (0.00, 0.50, 1.00, and 3.00) were assayed. Cowpea seedlings were planted and later harvested after 30 days of germina-tion. Microorganisms from rhizosphere treated with glyphosate were cultured and identified using selective media Wakesman A and B agar. The activity of isolates were evaluated by Tricalcium phosphate solubilization and screening for phosphatase in a Pikovskaya me-dium.. Results: Bacillus cereus, Bacillus subtilis, Micrococ-cus luteus, Pseudomonas aeruginosa, Proteus mirabi-lis, Bacillus pumilis, Staphylococcus aureus, Aspergil-lus flavus, Rhizopus nigrifican, and Aspergillus sapro-phyiticus were obtained from the glyphosate treated soil. There was decrease in the bacterial and fungal population in the rhizosphere as glyphosate concentra-tion increased. The concentration of the solubilized Tricalcium phosphate ranged from 42.48 to 515.78gl-1. Micrococcus luteus, Bacillus subtilis, Proteus mirabi-lis, Aspergillus flavus, Aspergillus saprophyticus iso-lated at the different concentrations of glyphosate have increased phosphate solubilization with reduction in their pH. Proteus mirabilis showed the highest phos-phatase activity (23.157mM/min/ml) at 30hrs and As-pergillus saprophyticus showed highest phosphatase activity (35.263 mM/min/ml) at 72hrs. Bacillus sub-tilis had the lowest protein concentration (3.034mg/ml) at 12hrs. Conclusion: This study showed that these rhizosphere microorganisms when applied as inoculants into the soil at different concentration of glyphosate can help increase the availability of soluble phosphates
Sustainbility assessment of selected additive manufacturing processes
Sustainable manufacturing has risen to a peek of interest for organizations who are seeking out methods of producing their material with minimal environmental impacts for an eco-friendlier product. Users of additive manufacturing technologies are faced with lack of centralized source of material information or process information which will be useful for sustainability assessment. A material information model (MIM) which is modified to capture several information about the build material selected and the role it plays across the product life phases is proposed. In this model, a clarification on ways to utilize elemental data (characteristics – based) to gauge the impact of the materials is discussed. Secondly, a method for analyzing the social performance of an additive manufacturing process is presented. In this method, various indicators are identified and grouped into a scale of points, to evaluate the social performance. Lastly, a model for the sustainability assessment performance of additive manufacturing process is developed. The three aspects captured are grouped into the three pillars of sustainability (social, economic, and environmental) and integrated to evaluate the sustainability assessment performance model.
Keywords: Sustainability; Sustainability Assessment; Additive Manufacturin
Small hive beetle infestation levels of honey bee colonies correlate with precipitation and forest cover
Small hive beetles (SHBs) are parasites of social bee colonies endemic to Africa and have become a widely distributed invasive species. Damage to colonies in the new ranges seems to be governed by higher infestation levels, but the factors underlying SHB numbers are poorly understood. Since SHBs pupate in the soil outside of colonies, local temperature and humidity are likely to underlie infestation levels. Here, we conducted a survey in Nigeria of 82 honey bee colonies, Apis mellifera adansonii (26 apiaries, 14 states), in both forest and savannah with a range of temperatures and precipitation. We recorded significantly higher SHB infestation levels in forests compared to savannah. While there was no significant correlation between local temperature and SHB infestation levels, a significant positive correlation was found between local rainfall and SHB numbers in colonies. Under the temperature conditions of the study region, precipitation and a forest cover appear to impact SHB infestation levels of honey bee colonies. Our data suggest that new SHB distribution ranges with both forests and high precipitation will be especially at risk
Challenges Associated With The Honey Bee (Apis Mellifera Adansonii) Colonies Establishment In South Western Nigeria
The southwestern part of Nigeria is a tropical rainforest region having
many local beekeepers. These beekeepers have experienced decline in
colony establishment in the recent past. A study carried out in Lagos,
Ogun and Osun states between December 2009 and September 2011 examined
14 randomly selected commercial bee farms for problems associated with
decline in colony establishment. Sampling and treatments were split
equally between each apiary and three colonies were selected in each.
All the colonies were housed in Tanzania/local top bar hives. There
were 58.34, 44.84 and 40.61 average percentage declines in colony
establishment in Lagos, Ogun and Osun States, respectively. Presence of
pests and diseases, pesticide poisoning, poor hive and seasonal
management, ecological problem and lack of queen rearing were potential
problems identified by the beekeepers. All the apiaries had pests like
Crickets, Ants (Companotus pennsylvanicus), Small Hive beetle (Aethina
tumida), Termites (Macrotermes spp) and Spider (Lactrodectus mactan).
Varroa mite infestations were found in 33 (78.57%) of apiaries
sampled. There was no significant difference between the levels of
Varroa infestation in all the colonies during the dry and wet seasons
at confidence interval of 95 percent (t = 1.542, df = 13, p = 0.147
(p> 0.05). Nosema spores were found in 27 (64.29%) colonies
examined. The number of spores range from 16 x 103 to 30.4 x 103. There
were no significant differences in the infection from colony to colony,
apiary to apiary and between dry and wet seasons (t = - 0.094 df = 11,
P = 0.927 (P > 0.05). Diseases like American and European foulbrood
were absent while chalkbrood disease was prevalent. Environmental
factors of high temperature, high rainfall and high relative and hive
humidity enhanced the spread of pests and disease pathogens. Many
insecticides were constantly applied by the farmers on the crops in the
surrounding farmland. Two of the commonly used insecticides DDVP
(Dichlorvos) and Cyperforce (Cypermetrin) were discovered to have
increased mortality on worker honey bees with progressively larger
doses. It was obvious that insecticide toxicity had a significant
effect on the colony. Hence, ecological and management problems had
contributed to the decline in colony establishment in this area
PCR Diagnosis of Small Hive Beetles
Small hive beetles (SHBs), Aethina tumida, are parasites of social bee colonies native to sub-Saharan Africa and have become an invasive species at a global scale. Reliable Polymerase Chain Reaction (PCR) diagnosis of this mandatory pest is required to limit its further spread and impact. Here, we have developed SHB primers, which amplify for 10 native African locations and 10 reported introductions, but not for three closely related species (Aethina concolor, Aethina flavicollis, and Aethina inconspicua). We also show that adult honey bee workers can be used as matrices for PCR-based detection of SHBs. The sensitivity of this novel method appears to be 100%, which is identical to conventional visual screenings. Furthermore, the specificity of this novel approach was also high (90.91%). Since both sensitivity and specificity are high, we recommend this novel PCR method and the new primers for routine surveillance of hives in high-risk areas
PCR Diagnosis of Small Hive Beetles
Small hive beetles (SHBs), Aethinatumida, are parasites of social bee colonies native to sub-Saharan Africa and have become an invasive species at a global scale. Reliable Polymerase Chain Reaction (PCR) diagnosis of this mandatory pest is required to limit its further spread and impact. Here, we have developed SHB primers, which amplify for 10 native African locations and 10 reported introductions, but not for three closely related species (Aethinaconcolor, Aethinaflavicollis, and Aethinainconspicua). We also show that adult honey bee workers can be used as matrices for PCR-based detection of SHBs. The sensitivity of this novel method appears to be 100%, which is identical to conventional visual screenings. Furthermore, the specificity of this novel approach was also high (90.91%). Since both sensitivity and specificity are high, we recommend this novel PCR method and the new primers for routine surveillance of hives in high-risk areas