Browsing by Author "Oliver, Charlotte"
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- Insect Identification Laboratory Annual Report 2010Day, Eric R.; Pfeiffer, Douglas G.; Oliver, Charlotte (Virginia Tech, 2011)This report summarizes the activity of the Insect Identification Laboratory at Virginia Tech for 2010.
- Insect Identification Laboratory Annual Report 2011Day, Eric R.; Pfeiffer, Douglas G.; Dellinger, Theresa A.; Oliver, Charlotte (Virginia Tech, 2013)This report summarizes the activity of the Insect Identification Laboratory at Virginia Tech for 2011.
- Insect Identification Laboratory Annual Report 2012Day, Eric R.; Pfeiffer, Douglas G.; Dellinger, Theresa A.; Oliver, Charlotte (Virginia Tech, 2013)This report summarizes the activity of the Insect Identification Laboratory at Virginia Tech for 2012.
- Investigation of Wine Grape Cultivar and Cluster Developmental Stage Susceptibility to Grape Ripe Rot Caused by Two Fungal Species Complexes, Colletotrichum gloeosporioides, and C. acutatum, and the Evaluation of Potential ControlsOliver, Charlotte (Virginia Tech, 2016-04-15)Ripe rot of grape is caused by two fungal species complexes: Colletotrichum gloeosporioides and C. acutatum, both of which cause disease on a variety of crops, such as strawberry and apple. To investigate effect of cultivar and cluster developmental stage on the development of ripe rot, controlled environment and field studies were conducted during 2013-2014. We have identified that a certain level of infection could can take place on most cultivars tested from bloom to the near harvest. In most of the cases, significant cultivar and cluster developmental stage interaction effects were observed (P < 0.05) for the development of disease symptoms in both studies. In general, susceptible cultivar (Cabernet Franc, Cabernet sauvignon, and Chardonnay) demonstrated fluctuations of disease susceptibility among cluster development stages, while resistant cultivars (Merlot) showed consistently low level of the disease throughout the season. To investigate the effect of eleven ten modes of action for control of C. gloeosporioides and C. acutatum, two methods, alamarBlue® assay and inoculation on fungicide-treated detached fruits, were used. Protective fungicides (mancozeb, captan, and copper) as well as some of newer formulations such as azoxystrobin and tetraconazole were identified as excellent products against ripe rot of grape. Four additional materials were identified as good potential candidates to investigate further. The information gained from these studies will help growers to determine the critical period for ripe rot management and chemicals to be applied for management. With better control of cluster rot pathogens, Virginia growers can experience an increase in yield and wine quality.
- A NitroPure Nitrocellulose Membrane-Based Grapevine Virus Sampling Kit: Development and Deployment to Survey Japanese Vineyards and NurseriesNita, Mizuho; Jones, Taylor; McHenry, Diana; Bush, Elizabeth; Oliver, Charlotte; Kawaguchi, Akira; Nita, Akiko; Katori, Miyuki (MDPI, 2023-10-17)We developed a NitroPure Nitrocellulose (NPN) membrane-based method for sampling and storing grapevine sap for grapevine virus detection. We devised an efficient nucleic acid extraction method for the NPN membrane, resulting in 100% amplification success for grapevine leafroll-associated virus 2 (GLRaV2) and 3 (GLRaV3), grapevine rupestris stem pitting-associated virus (GRSPaV), grapevine virus A, grapevine virus B, and grapevine red blotch virus (GRBV). This method also allowed the storage of recoverable nucleic acid for 18 months at room temperature. We created a sampling kit to survey GLRaV2, GLRaV3, and GRBV in Japanese vineyards. We tested the kits in the field in 2018 and then conducted mail-in surveys in 2020–2021. The results showed a substantial prevalence of GLRaV3, with 48.5% of 132 sampled vines being positive. On the other hand, only 3% of samples tested positive for GLRaV2 and none for GRBV.
- Phylogeny, histological observation, and in vitro fungicide screening and field trials of multiple Colletotrichum species, the causal agents of grape ripe rotOliver, Charlotte (Virginia Tech, 2019-01-31)Colletotrichum acutatum and C. gloeosporioides are fungal plant pathogens that have a global distribution, extensive host range, and convoluted taxonomy. Both species can cause grape ripe rot and are considered endemic to Virginia US. In 2012, C. acutatum and C. gloeosporioides were reclassified into species complexes that consist of 31 and 22 accepted species, respectively. The objectives of this study were to: 1) survey Virginia vineyards for grape ripe rot, and morphologically and phylogenetically identify isolates to the species within the complexes, 2) conduct an in vitro fungicide assay to screen fifteen commercial fungicides and combinations of two fungicides for efficacy to control isolates from seven Colletotrichum species from Virginia vineyards, 3) sequence gene fragments from three subunits of the SDH enzyme in the fungicide-screened isolates to observe potential resistance mutations, 4) investigate the susceptibility of three grapevine tissues to Colletotrichum species, 5) observe potential infection structures before and after the application of fungicides, 6) evaluate the efficacy of commercial fungicide controls of grape ripe rot in the field, and determine the most advantageous timing of applications. In my studies, I identified six Colletotrichum species: C. aenigma, C. conoides, C. fioriniae, C. gloeosporioides, C. kahawae, and C. nymphaeae. I also found two additional groups; an isolate similar to C. limetticola and C. melonis and a group of isolates that are similar to C. alienum, C. fructicola, and C. nupharicola. I also identified captan, and mancozeb as two potential active ingredients for control of grape ripe rot isolates from Virginia via the in vitro fungicide assay. Additionally, I found that combinations of two active ingredients could increase the efficacy of benzovindiflupyr, copper, and polyoxin-D. C. fioriniae germination and production of melanized appressoria was documented on leaves. I observed appressorium formation with isolates of two C. fructicola-like genotypes and C. nymphaeae, as well as secondary conidiation with isolates of C. aenigma, C. fructicola-like genotype 3, and C. nymphaeae on blooms. And finally, benzovindiflupyr, cyprodinil + fludioxonil pre-mix, and potassium phosphite + tebuconazole were identified as candidates for chemical control for grape ripe rot in the field.
- The Plant Disease Clinic and Weed Identification Lab Annual Report 2008(Virginia Tech. Plant Pathology, Physiology, and Weed Science Department, 2008)This is the 2008 annual report for the Plant Disease Clinic at Virginia Tech. The clinic provides plant disease diagnostic services to Virginia Cooperative Extension agents.
- The Plant Disease Clinic and Weed Identification Lab Annual Report 2009(Virginia Tech. Plant Pathology, Physiology, and Weed Science Department, 2009)This is the 2009 annual report for the Plant Disease Clinic at Virginia Tech. The clinic provides plant disease diagnostic services to Virginia Cooperative Extension agents.
- The Plant Disease Clinic and Weed Identification Lab Annual Report 2010(Virginia Tech. Plant Pathology, Physiology, and Weed Science Department, 2010)This is the 2010 annual report for the Plant Disease Clinic at Virginia Tech. The clinic provides plant disease diagnostic services to Virginia Cooperative Extension agents.
- The Plant Disease Clinic and Weed Identification Lab Annual Report 2011(Virginia Tech. Plant Pathology, Physiology, and Weed Science Department, 2011)This is the 2011 annual report for the Plant Disease Clinic at Virginia Tech. The clinic provides plant disease diagnostic services to Virginia Cooperative Extension agents.