Browsing by Author "Vaughan, Larry"
Now showing 1 - 11 of 11
Results Per Page
Sort Options
- Field survey of Drosophila suzukii (Matsumura) and Zaprionus indianus Gupta (Diptera: Drosophilidae) in Maui, HawaiiWillbrand, Brittany N. (Virginia Tech, 2019-04-18)Drosophila suzukii (Matsumura) and Zaprionus indianus Gupta (Diptera: Drosophilidae) are notable agricultural pests of soft-skinned fruits. Efficient field surveying is vital in an integrated pest management program. A survey to identify D. suzukii populations was conducted in four localities in Maui County among seven host-plants. During the survey, adult Z. indianus specimens were collected at all four localities in traps positioned in six of the seven host plants, suggesting that this previously unreported exotic species may already be well-established. Though there are currently no species-specific attractants available for D. suzukii or Z. indianus, characterization of attractant specificity by species and understanding how attractant efficacy varies with time is needed to advance development. A modification of the deli-cup trap was used and five attractants (brown rice vinegar, apple cider vinegar, red wine, brown rice vinegar plus red wine, apple cider vinegar plus red wine) were deployed in cherimoya in Kula, Maui, Hawaii. This investigation includes the first reported use of brown rice vinegar as an olfactory attractant in the United States and the results suggest that it may have higher specificity in the field capture of D. suzukii than apple cider vinegar, red wine, and apple cider vinegar with red wine. No significant differences were observed in attractant specificity for the field capture of Z. indianus. To examine attractant efficacy over time with and without a preservative, traps were maintained daily in cherimoya. The results suggest that attractants up to seven days old had a significant effect on mean field captures of D. suzukii and non-target drosophilids. Inclusive of all attractants and field ages, The addition of 1% boric acid (w/v) to the attractant solution increased the total field captures of D. suzukii by 44%, but no effect was observed for non-target drosophilids. These investigations enhance our current understanding of attractant specificity, which is the first step towards identifying selective compounds for a species-specific attractant. Furthermore, the first report of Z. indianus in Hawaii highlights the importance of examining interspecies interactions between endemic and invasive drosophilids and the need for the establishment of economic thresholds for vinegar fly pests.
- Internationalizing the Land Grant Mission: Lessons from SenegalAbaye, Azenegashe Ozzie; Archibald, Thomas G.; Vaughan, Larry; Thompson, Thomas L.; Thomason, Wade E.; Mbaye, Demba F.; Mamadou, L. O.; Abdoulaye, S.Y.; Gueye, Fatou; Snyder, Glenda; Guiesse, Bineta; Jamison, Kathleen; Vashro, Taylor N. (Virginia Cooperative Extension, 2018-03-20)Discusses using the land grant university model on an international level, in this case program development in Senegal.
- An Invasive Fruit Fly, Bactrocera dorsalis (Tephritidae), on Mango in Senegal: Impact on Mango Crop Production and Value, Marketing Practices, and ManagementBalayara, Assa (Virginia Tech, 2016-07-12)The oriental fruit fly, Bactrocera dorsalis Hendel, is an economic tephritid that invaded Senegal in 2004 (Vayssieres et al. 2011). This work determined 1) Impact of B. dorsalis on mango crop production and value, and marketing practices, 2) Effect of neem and kaolin on its behavior and development (laboratory and field), and 3) Effect of treated soil with neem seed cake (NSC) and neem seed powder (NSP) on the larval-pupal survival and development (laboratory and field). Results revealed crop value (price/kg) was associated with infestation levels. P<0.0001, crop value decreased in highly infested orchards. Southern Orchards were heavily infested than northern orchards. Early harvest, orchard sanitation, decreasing the purchase quantity, sorting infested mangoes and lowering prices were strategies used by growers and traders. Laboratory bioassays showed females landed and spent time on fruit identically on control and neem. On kaolin there were fewer landings and less time spent. P<0.0001, mean pupae was higher in control than in treated mangoes. In the field, percent of infested mangoes was higher in neem than in control and kaolin. However, the number of emerged flies was higher in the control than in either the neem or kaolin-treated fruit. Treated soil with NSC and with NSP did not have effect on pupation; all larvae pupated in the lab. However, treated soil decreased significantly the number of emerged flies. In the field, there were no significant differences between untreated and treated soil in number of emerged flies.
- IPM CRSP Annual FY 2012 Annual Report(Virginia Tech, 2013-04)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP Annual Report, Phase III – Year Five: 2008-2009(Virginia Tech, 2009)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP Annual Report, Phase III – Year Three: 2006-2007(Virginia Tech, 2007)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP Annual Report, Phase III – Year Two: 2005-2006(Virginia Tech, 2006)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP Annual Report, Phase III: 2007-2008(Virginia Tech, 2008)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP Annual Report, Phase IV – Year One: 2009-2010(Virginia Tech, 2010)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- IPM CRSP FY 2011 Annual Report(Virginia Tech, 2011)Published every year, the annual reports detail work, accomplishments, training, and publications from each of our programs.
- Mungbean [Vigna radiata (L.) Wilczek]: Protein-rich Legume for Improving Soil Fertility and Diversifying Cropping SystemsDiatta, Andre Amakobo (Virginia Tech, 2020-04-21)Drought, salinity, and low soil fertility have negative impacts on agricultural productivity, resulting in food scarcity and nutritional insecurity, particularly in Sub-Saharan Africa. Mungbean [Vigna radiata (L.) R. Wilczek] has seen increased interest as a short-duration and drought tolerant legume crop, capable of atmospheric N₂ fixation. Mungbean is a protein and iron-rich legume and can be used as vegetable or grain for human consumption or multipurpose crop. At present, few studies have simultaneously explored the best agronomic practices for mungbean cultivation and evaluated its potential for increasing crop yields via intercropping systems and improving soil fertility through biological N₂ fixation. To understand the agronomic practices and soil physical properties limiting mungbean production, the impacts of two mungbean cultivars (Berken and OK2000) with and without inoculation with Bradyrhizobium spp. grown in loamy sand and silt loam soils on mungbean growth and yield were investigated under glasshouse conditions. Promising results from this study led to the introduction of mungbean into pearl millet systems in Senegal and evaluation of the effects of intercropping on growth, yields, land equivalent ratio (LER), canopy cover estimates, and normalized difference vegetation index (NDVI). Finally, we evaluated plant growth and N₂ fixation of five mungbean genotypes grown in two soil textures using the ¹⁵N natural abundance technique leading to recommendations for those with the greatest overall benefit to the cropping system. The literature review shows mungbean often proposed as a strategic crop for increasing legume diversification within current cropping systems and providing increased food security as well as market diversification and economic sustainability. The greenhouse study revealed that OK2000 cultivar produced significantly higher yield when inoculated and planted on a silt loam soil than other treatments, indicating the importance of inoculation and soil texture in mungbean establishment. Intercropping mungbean and millet significantly (p≤ 0.05) increased combined yields (35% to 100% increase) and LER compared to sole millet cropping systems. Canopy cover estimates and NDVI values significantly increased up to 60% and 30%, respectively, in millet-mungbean intercropping over millet alone. The N2 fixation study showed that %Ndfa of mungbean was higher when grown in the loamy sand soil (27% increase). However, soil N uptake (235 mg plant⁻¹) and amount of N fixed (67 mg plant⁻¹) were greater in the silt loam soil. Among genotypes, IC 8972-1 significantly (p≤ 0.05) derived less N from the atmosphere (23%) but took more soil N (155 mg plant⁻¹) which yielded significantly greater dry biomass (7.85 g plant⁻¹) and shoot N content (200 mg plant⁻¹). The results from the N₂ fixation study indicated that choice of mungbean genotype can contribute to reducing N needs of agricultural systems. Overall, this research project demonstrated that mungbean has the potential for diversifying smallholder agriculture and adding biologically fixed N into soils, in line with transformative adaptation strategies being promoted for sustainable agriculture. Further research and development programs on good cultural practices, adaptation to cropping systems, and nutritional benefits for human consumption can promote mungbean cultivation in SSA.