The influence of under-vine cover crops on soil health: taking a root-centric approach to microbiome analysis
PI : M. Centinari; Co-PIs: D. Eissenstat, T. Bell
Graduate student: S. Fleishman
Funding agency: USDA AFRI Foundational Program
Our study aims to understand how root traits structure the microbiome in response to multiple management practices (cover crops, rootstock selection) in grapevines. This will provide new insights into specific factors driving root-microbe interactions, moving beyond census-based descriptive approaches.
Our objectives are to: 1) define the major root traits (e.g., age, branching order, type) structuring root and rhizosphere microbial composition, 2) examine how proximity to grass cover crop roots shift the root-associated microbiome of a woody fruit crop species, and 3) characterize root dynamics and rhizospheric microbial community abundance and diversity by depth in a woody perennial system in response to management practices.
Evaluating the impact of under-trellis groundcover practices on winegrape production profitability and sustainability
PI : M. Centinari; Co-PI: K. Kelley
Funding agency: PA Wine Marketing and Research Board
The goal of this project is to implement weed control practices in vineyards that reduce herbicide use and excessive vine vegetative growth while increasing the profitability of growing premium quality grapes in Pennsylvania. With that goal in mind, the objectives of this study are to assess the effects of annual and perennial cover crops planted directly under the trellis on vine vegetative growth, productivity, fruit quality, disease incidence, winter hardiness, and weed suppression. We will also estimate the financial implications associated with different weed control strategies (herbicide applications, annual and perennial under-trellis cover crops) together with assessing any economic benefit that may occur if consumers’ willingness to pay for “sustainable” wines is higher than “conventional” wines. Lastly, we will survey grape growers in the Commonwealth to learn what challenges they face in managing weeds and excessive vine vigor and what barriers prevent them for adopting alternative under-trellis management practices.
Creeping red fescue (Festuca rubra) growing under Noiret (Vitis sp.) vines (right side) compared to a vegetation-free under-vine strip (left side)
Evaluating the impacts of Spotted Lanternfly on grapevine health to develop more targeted control approaches
PI : M. Centinari; Co-PIs: J. Urban, H. Leach, D. Eissenstat
Graduate student: A. Harner
Funding agency: PA Department of Agriculture
The Spotted lanternfly (SLF; Lycorma delicatula) is an invasive pest whihc represents a major threat to eastern US grape and wine industry. SLF is a voracious phloem-feeder and tends to attack a single tree or vine in high numbers. Heavy-phloem feeding can compromise the ability of the vines to ripen the crop and presumably reduces stored carbohydrates and nutrients to support next season’s growth. Our goal is to provide stakeholders with research-based information regarding the impacts of SLF on grapevine health and productivity. We are investigating how population density of SLF adults affect grapevine physiological processes that are closely related to fruit quality and vine health.
Introducing known amount of SLF on caged vines.
Does delaying budburst reduce the risk of frost damage while maintaining grape and wine quality? Comparing the effectiveness of pruning time and Amigo application
PI : M. Centinari; Co-PIs: H. Hopfer, M. Kelly, R. Elias
Graduate student: M. Persico
Funding agency: PA Wine Marketing and Research Board
Crop losses and delays in fruit ripening caused by spring freeze damage represent an enormous challenge for wine grape producers around the world. This multi-year study aims to compare the effectiveness of two frost avoidance strategy (application of a food grade vegetable oil-based adjuvant and delayed winter pruning) on delaying the onset of budburst, thus reducing the risk of spring freeze damage. Our objectives are to: i) evaluate if the delay in budburst impacts grape production and fruit maturity at harvest, as well as chemical and sensory wine properties; ii) elucidate the mechanism of action of the vegetable oil-based adjuvant through an examination of bud respiration and potential phytotoxic effects; iii) assess the impact of the two frost avoidance strategies on carbohydrate reserve storage and bud freeze tolerance during the dormant season.
Defining regional typicity of Grüner Veltliner wines
PI : M. Centinari; Co-PIs: R. Elias, B Hed, H. Hopfer, K. Kelley
Graduate student: A. Harner, S. Keller
Funding agency: PA Wine Marketing and Research Board
Grüner Veltliner, a world-renowned grape variety mainly grown and produced in Austria, is relatively new to Pennsylvania. It was first planted in the state around 2003 and since then has received increased industry attention as it adapts well to Pennsylvania growing conditions and can be used to produce various styles of wine. This multi-year study aims to characterize the environmental, viticultural, and sensory factors that drive typicity, defined as the “perceived representativeness” of a wine produced from a designated area, of Grüner Veltliner across the Commonwealth, and to develop marketing strategies that best appeal to current and potential Grüner Veltliner wine consumers. Wines made from Pennsylvania-grown Grüner Veltilner grape sourced from various regions across the state will be analyzed through basic wine chemistry, sensory and compositional analyses, including volatile and non-volatile flavor profiling. Results from this study will provide growers and wine producers with targeted recommendations that are needed to improve premium wine production through an increased understanding of the processes responsible for developing quality attributes in Grüner Veltliner wines while enhancing marketing techniques.
Map of Pennsylvania indicating the location (colored pin) of the experimental sites (photo credit S. Keller)
Survey for grapevine leafroll viruses in Pennsylvania
PI : B. Hed; Co-PIs: M. Centinari, C. Rosa
Graduate student: A. Varaska
Funding agency: PA Wine Marketing and Research Board
Infection of grapevines by grapevine leafroll-associated viruses (GLRaVs) can have serious consequences on yield, vigor, cold hardiness, and most notably fruit/wine quality. These viruses are widespread throughout many grape growing regions of the world, including the eastern US. The golas of our multi-year study are to: a) Examine and plot the spread of GLRaV-1 and -3 within 6 vineyard blocks that have been identified as having leafroll infected vines; b) Examine and report the effects of GLRaV-1and 3 on grapevine vegetative growth, yield, fruit chemistry, and bud freeze tolerance at 6 locations with different weather regimes; and c) characterize the influence of inter- and intra-seasonal weather conditions on virus-infected grapevine performance at all 6 vineyard locations.
Boosting polyfunctional thiols and other aroma compounds in white hybrid wines through foliar nitrogen and sulfur application
PI : R. Elias; Co-PIs: M. Centinari, H. Hopfer
Funding agency: PA Wine Marketing and Research Board
The quality of aromatic white wines is heavily influenced by the presence of low molecular weight, volatile compounds that often have exceedingly low aroma threshold values. Polyfunctional varietal thiols are an important category of these compounds. This project aims to provide research-based viticultural practices that could lead to increases in beneficial varietal thiols in white hybrid grapes. The expected increase in overall wine quality will be validated both by measuring the concentrations of these desirable compounds (i.e., thiols) in finished wines using instrumental analysis and by human sensory evaluation, thus providing a link between the viticultural practice of foliar spraying and the improvement of overall wine quality