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Publication The Removal of Polyethylene Microplastics in Water Using a Sawdust Filter Mediated with Polyphenol Coatings(2024-09) Sentman, JulieThe developing research into microplastics shows that the need to find ways to remove them are urgent. Through the modification of ligno-cellulosic frameworks with polyphenol coatings to create a filter, polyethylene can be captured. This novel filter was developed using a wet packing method and a commercial fish pump to move the plastics from the Milli-Q solution to the filter. Through Ï€-Ï€, electrostatic, and physical interactions, pristine and degraded polyethylene was removed from a microplastic solution being pumped through the filter. This filter provides a look at how an organic waste, such as wood, can be utilized to remove contaminants and used in commercial settings, such as wastewater treatment facilities.Publication Evaluation The Nitrogen Needs And Efficiency Of Rizhobia Strains To Provide Nitrogen To Chipilin (Crotalaria Longirostrata Hook. And Arn.)(2013-01-01) Camarillo Castillo, Fatima del RosarioEVALUATION THE NITROGEN NEEDS AND EFFICIENCY OF RHIZOBIA STRAINS TO PROVIDE NITROGEN TO CHIPILIN (Crotalaria Longirostrata HOOK. AND ARN.) FEBRUARY OF 2013 FATIMA DEL ROSARIO CAMARILLO CASTILLO, B.A., AUTONOMOUS UNIVERSITY OF CHAPINGO M.A., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Francis X. Mangan Chipilin (Crotalaria Longirostrata) is a leguminous plant native to Central America and Southern Mexico and used in the preparation of traditional dishes in this region. Starting in 2009, farmers in Massachusetts have been growing chipilin with a weekly production of 800 kg∙ha-1. However, as much as 300 kg∙ha-1 of nitrogen has been necessary to apply to the soil in order to obtain a marketable leaf quality. With the goal to determine the nitrogen requirements of chipilÃn and to quantify the capacity of selected stains to infect and provide nitrogen for this crop, two-field experiments were conducted at the UMass Research farm at Deerfield, Massachusetts, in an occum fine sandy loam soil (coarse-loamy, mixed, mesic Fluventic Dystrudept) soil as a randomized complete bock design with five replications. For the field trial in 2011, nitrogen rates were (kg∙ha-1): 40, 80, 120, 160, 200 and 240 and 0, 40, 80, 120, 160, 200, 240 and 280 in 2012 in combination with four Rhizobia strains: Bradyrhizobium sp. (Vigna), Rhizobium leguminosarum biovar, Bradyrhizobium USDA 3384 and no Rhizobia were the treatments. Based on the results obtained, nitrogen fertilizer application of 80 kg∙ha-1 was economically sufficient for chipilin to reach optimum yield. However higher nitrogen rates are needed to obtain marketable leaf color and quality. Additionally a greenhouse experiment set up as a factorial experiment with five replications was conducted with seven nitrogen concentrations (mg N∙L-1)-; 0, 26.25, 52.5, 105, 157.5, 210 and 262.5 mg∙L1 and the three Rhizobia strain for the previous experiment plus Bradyrhizobium USDA 2370 as treatments. Results suggest from Bradyrhizobium USDA 3384 is not an efficient strain for chipilin, and Rhizobium leguminosarum biovar potentially may provide the most nitrogen of the strains evaluated. In the greenhouse trial, nodules number per plant decreased with the increase in nitrogen applications, but this was not the case in the field trial in 2012. Nodules were found on the root of chipilin plants in the control. This is suspected to be due to one of the following possibilities: Rhizobia inoculum presence in the seed, Rhizobia in the soil (in the field trial) or contamination during the setup of the experiment.Publication Evaluation of Varieties and Cultural Practices of Okra (Abelmoschus Esculentus) for Production in Massachusetts(2011-09) Mateus, RenatoOkra (Abelmoschus esculentus) is a traditional crop commercially cultivated in many parts of the world. Fresh okra has a high nutritional value and grows very quickly with high temperatures, which lends its production to more tropical areas. This study was implemented to evaluate different varieties of okra and determine the optimum density for production in Massachusetts. Two experiments were carried out between May and September of 2009 and 2010 at the UMass Research Farm in South Deerfield, MA. For the variety trial in 2009: Annie Oakley, Baby Bubba, Cajun Delight, Chifre de Veado, Clemson Spineless, Millionaire, North & South and Santa Cruz 47. The immature pods were harvested when reached 70 mm in length (size desired by the market in the USA) and in another plot for Chifre de Veado and Santa Cruz 47 the pods were harvested when reached 100 mm (market in Brazil). The density trial was set in a randomized complete block design with seven different plant spacings (7.5, 15.0, 22.5, 30.0, 38.5, 45.0 and 52.5 cm) in double row of plants of Cajun Delight. The pods were harvested three times a week, counted and weighted. Analyses of variance were performed by SAS, and means were compared using Duncan’s new multiple range test (P = 0.05) and orthogonal polynomial comparisons. In 2010, Santa Cruz 47 harvested based on Brazilian market size had the best performance over the season with the yield of 17.86 ton.ha-1 and similar statistic results comparing to North and South (15.99 ton.ha-1) and Annie Oakley (15.24 ton.ha-1). The differences among the plant spacings in 2010, were represented by a quadratic relationship, where the greater plant spacing for yield was ‘52.5 cm’ with the total yield of 14.91 ton.ha-1. Both trials in 2009 were negatively affected by the soil-borne fungus Verticillium spp., which, combined with the cold and wet weather, became very aggressive, especially in the end of the season. The results show that the varieties: North and South, Annie Oakley, Cajun Delight, Millionaire, Clemson Spineless, Santa Cruz 47 can be commercially grown in Massachusetts and the recommended plant spacing of okra is 52.5 cm.Publication Comparative Genome Analysis between Agrostis stolonifera and Members of the Pooideae Subfamily Including Brachypodium distachyon(2011-09) Araneda, Loreto PUnderstanding of grass genome structure and evolution has been significantly advanced through comparative genomics. The genomes of most cool-season forage and turf grasses, belonging to the Pooideae subfamily of the grasses, remain understudied. Creeping bentgrass (Agrostis stolonifera) is one of the most important cool-season turfgrasses due to its low mowing tolerance and aggressive growth habit. An RFLP genetic map of creeping bentgrass using 229 RFLP markers derived from cereal and creeping bentgrass EST-RFLP probes was constructed for a comparative genome analysis. This genetic map was compared with those of perennial ryegrass, oat, wheat, and rice. Large-scale chromosomal rearrangements between the map of creeping bentgrass and the respective maps of the Triticeae, oat, and rice were observed. However, no evidence of chromosomal rearrangements between the maps of creeping bentgrass and perennial ryegrass was detected, suggesting that these recently domesticated species might be closely related than expected. Further comparative genome analysis of creeping bentgrass was performed with the genome sequences of Brachypodium distachyon using sequences of the above-mentioned RFLP mapped markers and 8,470 publicly available A. stolonifera EST (AgEST) sequences. A total of 24 syntenic blocks were identified between the Agrostis linkage groups and the B. distachyon chromosomes. Orthologous loci of AgESTs (678) were identified in the B. distachyon genome, and these loci can be utilized in further comparative mapping of Pooideae species. Insights from comparative genomics with B. distachyon will be useful for genetic improvement of Agrostis spp. and provide a better understanding of the evolution of the Pooideae species.Publication Analysis of the Market for Massachusetts Apples for Markets in Central America(2011-09) Alvarado, Mildred L.This study of the market for apples produced in Massachusetts for markets in Central America was implemented in order to identify and quantify business possibilities in that region. Apple consumption in Central America is very high and growing, with an increase of more than 100% from 2005 to 2009, from $14 million worth of apples in 2005 to $31 million in 2009. There are increased opportunities for apples from the United States to gain access to this market due to the Dominican Republic-Central American Free Trade Agreement (DR-CAFTA), enacted in 2005. This trade agreement lowers barriers and tariffs of products between the US and these countries. Apples are a very important commodity in Central America. For example, apples available for sale in El Salvador are imported from Chile, USA, Guatemala, and sometimes from Canada. In 2009, 52% of the apples imported by El Salvador were from the United States, 43% from Chile, and 4.8% from Guatemala. The majority of apples that are exported to El Salvador from the United States come from Washington State, followed by California and Oregon. During the summer of 2010, 165 consumers were surveyed and several supermarkets chains, wholesalers and local markets in El Salvador were canvassed in order to obtain information on the current apple market in El Salvador, with the goal to assess opportunities for apples from Massachusetts to enter this market. The most important attributes used by those surveyed in El Salvador when purchasing apples were quality (including taste, firmness, and size) and price. Medium and small sized apples are preferred as they are more economical for families, providing an opportunity for US growers to sell their smaller fruit that US consumer do not prefer. Delicious and gala are the varieties sold mostly. Apples are usually bought in supermarkets, fruits stalls in municipal markets, and from fruit peddlers on the street and on buses. During the Christmas holidays of 2010, another marketing survey was conducted to determine the acceptance in Central America of McIntosh apples from Massachusetts. Nearly 800 consumers were surveyed at five Wal-Mart stores in El Salvador after being given samples of McIntosh apples produced in Massachusetts. Consumers particularly liked the sweet-tart flavor, juiciness, and firmness. Due the results of these surveys, Wal-Mart Centro America Mexico expressed interest in developing a relationship with apple growers in the Northeastern United States.Publication Evaluation of Seed Sources and Cultural Practices of Maxixe (Cucumis anguria L.) for Production in Massachusetts(2011-02) Fernandes, Celina A PMaxixe (Cucumis anguria L.), also known as Burr gherkin and West Indian gherkin, was brought to Brazil from Africa during the slave trade. This crop was grown extensively in New England in the 18th and 19th centuries. There has been a tremendous increase of immigrants to the United States in recent years, and this has provided an opportunity for farmers to produce crops desired by these new and expanding markets. In order to benefit local farmers, two field experiments were implemented in 2009 and 2010 to address the effect of plant population, the use of a trellis and evaluate different seed sources of maxixe to assist producers interested in growing this crop in the Northeastern United States. The Trellis/Spacing trial was set up as a randomized–complete-block-split-plot design with five replications of ‘Trellis’ versus ‘No Trellis’ and within each trellis treatment there were five spacing between plants in the row: 15, 30, 45, 60, and 75 cm. The Seed Source trial was set up as a randomized complete block design with five replications and five sources of maxixe from five different seed companies: ‘Isla’, ‘Feltrin’, ‘Topseed’, ‘HF’, ‘Seed Savers Exchange’, and ‘Baker Creek Heirloom Seeds’. The five seed sources of maxixe are commercially viable for production in Massachusetts. The best plant spacing for marketable yield and marketable number of fruits was ‘15 cm’ in 2009; however, in 2010, the plant spacing that had the best marketable yield and the greater marketable number of fruits was ‘60 cm’ and ‘30 cm’, respectively. The use of trellis support indicated that the net returns on the ‘Trellis’ are higher than ‘No trellis’. However it is critical to understand the market preferences, such as size of the fruits and spines. This work speaks to the opportunities to supply the Brazilian markets and introduce this crop to non-Brazilian markets.Publication Examination of the Association Between In Vitro Propiconazole Sensitivity and Field Efficacy Among Five Diverse Sclerotinia homoeocarpa Populations on Turfgrass(2011-02) Popko, James TSclerotinia homoeocarpa F.T. Bennett, the causal agent associated with dollar spot, is a common and economically challenging turfgrass disease in North America. Acceptable turfgrass quality requires the optimization of cultural practices and the judicious use of fungicides. Sclerotinia homoeocarpa causes significant damage to turfgrass swards from May to October annually, therefore, requiring multiple fungicide applications to maintain satisfactory turfgrass quality throughout the growing season. Sterol demethylation inhibitor (DMI) fungicides are among the most widely used in the United States and frequent use has led to the development of fungicide resistance to the DMI fungicide class. The precise mechanism of DMI fungicide resistance in S. homoeocarpa is not completely understood, however over expression of the CPY51A gene or efflux transporter genes have been reported as the molecular mechanism for other fungal systems. Fungicide resistance to the DMI class exhibits a gradual population shift towards insensitivity that can be monitored using In vitro fungicide sensitivity assays. In vitro fungicide sensitivity assays have been used to detect fungicide sensitivity differences in different S. homoeocarpa isolates and currently serve as the most accurate methodology to detect DMI insensitivity in S. homoeocarpa. Documentation of DMI field efficacy on native S. homoeocarpa populations with differing in vitro sensitivities has not been examined thoroughly and would provide critical information regarding the association between in vitro fungicide sensitivity and DMI field efficacy. The objectives of this research are (i) to determine the association between in vitro propiconazole sensitivity and reduced field efficacy for five native S. homoeocarpa populations and (ii) to develop a qualitative in vitro sensitivity assay for detection of S. homoeocarpa isolates responsible for practical field resistance.Publication Nitrogen Dioxide in the Urban Forest: Exposure and Uptake(2010-09) Harris, Tanner B.Nitrogen dioxide (NO2) levels were measured inside and adjacent to canopies of urban trees in Springfield, MA, over two growing seasons. Nitrogen dioxide levels were consistently and significantly higher inside tree canopies compared to levels outside. During the second growing season, ozone (O3), temperature, and relative humidity (RH) were also measured using samplers co-located with the NO2 samplers. Ozone levels were significantly lower inside the canopy whereas temperatures were higher inside the canopy, and RH was not different between inner and outer canopy locations. The results corroborate theoretical models predicting elevated NO2 and depressed O3 levels inside tree canopies based on photochemistry, but put into question the mechanisms involved in generating these levels. In a separate study, the use of a common urban street tree (Acer rubrum) as a tool for measuring NO2 uptake under field conditions was evaluated using a model previously applied only to potted herbaceous plants and coniferous trees. Using potted saplings of A. rubrum located at locations with high or low NO2 levels in Springfield, MA, and Amherst, MA, we measured 15N stable isotope signatures (δ15N) and total N (%N) of leaves throughout the growing season. There was no significant difference in leaf δ15N or %N change between sites over the course of the season. Changes in δ15N were likely the result of input from N sources in the nutrient solution. Changes in %N followed a natural seasonal decline reported elsewhere in the literature. The study highlights the difficulties in applying this particular model to deciduous trees and suggests work needed to overcome these challenges.Publication Engineering Plants for Tolerance to Multiple Abiotic Stresses by Overexpression of AtSAP13 Protein and Optimization of Crambe abyssinica as a Biofuel Crop in Western Massachusetts(2010-09) Vaine, EvanAbiotic stresses such as drought, salt and exposure to toxic metals adversely affect the growth and productivity of crop plants and are serious threats to agriculture. We are currently working with an Arabidopsis family of proteins known as Stress Associated Proteins (SAPs). There are a total of 14 proteins in the Arabidopsis SAP family whose members have been suggested to provide tolerance to abiotic stresses in plants. For this project, we aim to characterize AtSAP13, which codes for a protein of 249 amino acid residues. Through overexpression, we investigated the sensitivity or tolerances provided by the overexpressed protein in comparison to wild-type plants. Our preliminary results showed that Arabidopsis plants overexpressing SAP13 showed strong tolerance to arsenite, cadmium, and zinc. A semi-quantitative RT-PCR was performed to analyze SAP13’s mRNA levels in wild type plants exposed to the same set of stresses. Tissue specific expression was analyzed using a GUS histochemical assay. Sub-cellular localization of AtSAP13 was analyzed by creating an in-frame fusion of SAP13 and enhanced GFP (eGFP). We set out to optimize growth conditions for Crambe abyssinica in order to determine if Crambe could be grown as a biofuel crop in New England. We have determined that Crambe can be grown successfully in the New England climate. We tested three fertilizer application rates, two different cultivars, and two different soil types for changes in yield. In the end, we observed the greatest increase in yield when planted on well drained soil.Publication Pollinator Populations in Massachusetts Cranberry, 1990 to 2009: Changes in Diversity and Abundance, Effects of Agricultural Intensification, and a Contribution to the North American Pollinator Survey.(2010-01-01) Notestine, Molly MIt is now widely accepted that over one-third of the global food supply depends upon pollinators. Risking severe ecological and economic implications, the status of the 4000 species of bees native to North America has been poorly understood due to a lack of long-term survey data. In this study, I conducted bee surveys on Massachusetts cranberry (Vaccinium macrocarpon Ait.) bogs from 2007-2009 and compared diversity and abundance data to those from historical surveys performed in 1990-1992 on the same bogs. I found that overall bee diversity declined severely in the 19-year survey period, while total bee abundance remained consistent. My data provide supporting evidence for the loss of North American bumble bees (Bombus spp.), but also provide the first evidence for declines in the U.S. in overall wild bee diversity. Maximizing the potential for agricultural landscapes to serve as quality pollinator habitat and identifying appropriate integrated pest management strategies should involve a comprehensive understanding of each species’ life history traits and conservation status. The loss of biodiversity associated with the intensification of agriculture has been well documented for several wildlife species but remains poorly understood for bees, which provide pollination to many agricultural crops. Most pollinator-dependent crops rely heavily on managed honey bees (Apis mellifera L.) for pollination. Four thousand other species of bees native to North America may provide pollination insurance in the event of honey bee losses, but without a clear understanding of how agricultural intensification affects wild bees, habitat conservation measures aimed at protecting them may be futile. In the second part of this study, I evaluated six metrics of agricultural intensification with respect to native bee diversity and abundance in Massachusetts cranberry bogs, including honey bee competition, bog management type (i.e. organic versus conventional), distance from epicenter of cranberry-growing region, toxicity of insecticide program, susceptibility of reproductive bees to insecticide, and surrounding land use. I found a clear association between reduced native bee diversity and abundance and the effects of increased agricultural intensification of the landscape. Recognition that native bee communities in North America are diminishing as a consequence of agricultural intensification may help to unify a movement toward improved conservation management.Publication Use of Short-Term Floods as an Additional Management Strategy for Controlling Dodder (Cuscuta gronovii Willd.) in Commercial Cranberry Production(2010-05) O'connell, James MDodder (Cuscuta gronovii Willd.) is a weed of serious concern to cranberry (Vaccinium macrocarpon Ait.) growers. It develops vigorously and has a long-lived seed bank. Cranberries are a perennial crop and therefore strategies available to growers of annual crops are not practical. Herbicides, the primary management tool for dodder, although effective, have a narrow window of application and extended seedling emergence after applications can result in escapes. This project examined the effect of water temperature on dodder seed germination and the use of short-term floods (less than 72 hr) for dodder management. Experiments investigated the effect of water temperature on dodder seed germination. Studies, ran twice, submerged dodder seed in water for 0 to 48 hr at 10, 15, and 20 C in one experiment (simulating spring water temperatures) and 0 to 48 hr at 15, 20, and 25 C in a separate experiment (simulating summer water temperatures). In Run 1, the effect of temperature on percent seed germination varied by flood duration; and by temperature alone in Run 2. Percent seed germination however, always fell within normal ranges (35-59%), indicating that flooding may not impact seed germination. Two 1-yr field studies were conducted to evaluate the use of short-term floods (24 to 48 hr) for managing dodder in cranberries. Two scenarios were simulated: cranberry beds with no emergent weed populations (cranberries alone) and cranberries with emergent weed populations (cranberries with additional host). There were three flood durations (0, 24, and 48 hr) and four flood initiations (1 to 4 wk after first seedling emergence). In 2006, mean percent germination from seeds incubated in Petri dishes was lower for seeds submerged 3 and 4 wk after first emergence (AFE) for the 48-hr flood durations. In 2007, mean percent germination for seeds submerged for 24 and 48-hr decreased for floods initiated at 4 wk AFE. Flooding 4 wk AFE resulted in lowest mean attachment ratings in both years and lowest mean dodder biomass on cranberry in the 2007 cranberry and tomato study, suggesting later flood initiation may provide better dodder management.Publication Cold Hardiness, 13c Discrimination and Water Use Efficiency of Perennial Ryegrass Genotypes in Response to Wilt-Based Irrigation(2010-05) Lanier, Jason DPerennial ryegrass (Lolium perenne L.) is a cool-season turfgrass susceptible to low temperature injury. Wilt-based (WB) irrigation is a common practice in scheduling turf irrigation as an alternative to well-watered (WW). Moisture stress has been shown to promote cold hardiness but this has not been investigated in response to WB irrigation. Measurements of 13C isotope discrimination (DELTA) are useful predictors of water use efficiency (WUE), drought resistance, evapotranspiration (ET) and salinity tolerance but the relevance to turfgrass cold hardiness has not been determined. DELTA analyses may enable more efficient screening protocols in breeding for improved cold hardiness. Objectives of this study were to examine perennial ryegrass genotypes in relation to cold hardiness, DELTA and WUE in response to WW and WB irrigation schedules, to compare genetic diversity between top-performing (TP) and bottom-performing (BP) perennial ryegrass genotypes, and to assess the predictive value of DELTA of for cold hardiness. Six genotypes were selected based on turf quality from the most northern NTEP location (Orono, ME) and included three TP (‘All Star 2’, ‘Mach I’ and ‘Sunkissed’) and three BP (‘APR-1234’, ‘Buccaneer’ and ‘WVPB-R-82’) genotypes. ET, yield, WUE, shoot water content, rooting potential, wilting tendency, DELTA and median lethal temperatures (LT50) using whole-plant survival were measured from greenhouse samples grown in weighing lysimeters in 2007 and 2008. Plant measurements in both years were based on sampling conducted at the last cycle after 68-d of irrigation with 100% of ET applied at leaf-roll (WB) versus ET replacement every 4-d (WW). Lower LT50 values were generally associated with low yield, low WUE and low shoot water content, whether the result of irrigation treatment or genotypic variation. TP genotypes demonstrated significantly lower LT50 temperatures (greater cold hardiness) in comparison to BP genotypes in both years. Modest cold hardiness enhancement with WB irrigation was highest for TP genotypes. Wilting tendency and DELTA were not reliable predictors of cold hardiness, although individual TP genotypes exhibited responses distinctly different than some BP genotypes. Further research is needed to investigate the physiological mechanisms of enhanced turfgrass cold hardiness in response to moisture stress.Publication Sorption of Bovine Serum Albumin on Nano and Bulk Oxide Particles(2010-02) Song, LeiManufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be made. Moreover, the relationship between adsorption maxima, which are related to protein conformational change and particle toxicity, and protein conformational change has not yet been studied. Therefore, in this work, the adsorption behavior of bovine serum albumin (BSA) protein on three types of nano oxide particles (viz., TiO2, SiO2, and Al2O3) was investigated in order to explore their interaction mechanisms, compared with that on regular bulk particles (BPs). The BSA adsorption maxima on oxide particles were regulated by the surface area of oxide particles. BSA adsorption was primarily induced by electrostatic attraction and ligand exchange between BSA and oxide surfaces. Surface hydrophilicity, surface charge and aggregation of oxide particles also affected their adsorption of BSA. Calculations suggested that a multilayer of BSA covered α-Al2O3, and single layer covered the other oxide particle surfaces. Primary structures of BSA molecules were adsorbed and changed on surfaces of oxide particles.Publication A Phytoremediation Study on the Effects of Soil Amendments on the Uptake of Arsenic by Two Perennial Grasses(2009-01-01) Klaber, NicaThe effects of varying concentrations of two chelators: EDTA, citric acid (CA), and phosphorus on the accumulation of arsenic in soil by two perennial grasses, Leersia oryzoides and (rice cut-grass) Festuca arundinacea (tall fescue). Each experiment was run for eight weeks, after which plants were harvested, oven-dried, digested in acid and analyzed using an ICP-OES. Phosphorus soil amendments were applied as 0, 15, 30, 60, 120 mg P/kg soil. For the first chelator experiment, CA and EDTA concentrations of 0, 2.5, and 5.0 mmol/kg soil were added in pulse form to the soil. In the second chelator experiment, concentrations of CA were added in 0, 2.0, 4.0 mmol/kg soil and EDTA was added as 0, 0.25, 0.50 mmol/kg soil. Both plant species accumulated enough arsenic in the root and shoot tissues to be considered at hyperaccumulator species. Citric acid produced comparable results with EDTA, and is considerable much safer for the environment than any synthetic chelator. Certain soil amendments (citric acid and phosphorus) and hyperaccumulator species used in this study warrant further research in the field.Publication Combining Biorational Compounds to Optimize Control of Grape Powdery Mildew (Uncinula Necator)(2009-09) Fiedler, KathrynIn the Northeast, powdery mildew (PM), caused by Uncinula necator (Schewein.) Burrill is one of the most important grape diseases in terms of economic loss. It has been established that cultural practices, including proper sanitation, are the first step in preventing disease, and fungicide sprays are regularly applied to manage the disease. Currently, fungicides that successfully control PM have a strong potential to develop pathogen resistance, and alternatives with low risk of initiating resistance are not as effective in disease control. Our approach to this emerging resistance dilemma is to combine a systemic acquired resistance inducer (salicylic acid and potassium phosphate) with a topical fungicide, potassium bicarbonate. To determine each treatment’s level of efficacy, multiple aspects of infection and defense were quantified and qualified, including germination rate, lethality, lignin formation, callose formation, and vine and leaf growth. The first trial showed potassium bicarbonate and the standard fungicide (Pristine) inhibited the most germination and was most lethal against PM conidia. Potassium phosphate had little effect on germination and conidia death, and when combined with bicarbonate there was no different than the water control. In the second trial, the biorational mixture was able to reduce the level of powdery mildew infection significantly more than the other compounds, including the commercial standard. The salicylic acid and potassium bicarbonate mix may be successful enough to use in the vineyard to determine if the compound can tolerate field conditions with the same level of efficacy.Publication Publication Integrated Control of Potato Leafhopper on Apple: Implications for Fireblight Management(2005) Leahy, Kathleen P.The plant growth retardant prohexadione-Ca (Apogee®) is able to suppress the bacterial disease fireblight (causative agent: Erwinia amylovora) on apple, and shows some suppression of several other common orchard pathogens and insects. The potato leafhopper, Empoasca fabae (Harris), is a frequent pest of apple orchards in the Northeast and mid-Atlantic U.S., which can require multiple insecticide applications to control severe infestations, and which has been implicated in the dissemination of fireblight. The efficacy of prohexadione-Ca in suppressing potato leafhopper was compared with that ofimidacloprid (Provadoâ„¢), a commonly used orchard insecticide, which is known to have excellent efficacy on leafhoppers. A factorial experiment with +/- prohexadione-Ca and+/- imidacloprid as the treatments was conducted, using a randomized complete block design, in two separate orchards over two growing seasons. Prohexadione-Ca and imidacloprid suppressed potato leafhopper feeding damage comparably in both.years, and an additional level of suppression was documented when both materials were used. It appears that commercial orchardists will be able to control potato leafhoppers with prohexadione-Ca using little or no insecticide.Publication The effects of nitrogen on the chemical composition of yarrow (Achillea millefolium L. complex) /(2001-01-01) Russell, Fiona E.Publication Publication Field methods of spodosol identification in northwestern Worcester County, Massachusetts /(1991) Frazer, Brenda Edmund