Location: Crops Pathology and Genetics Research
Project Number: 2032-21220-007-00-D
Project Type: In-House Appropriated
Start Date: Jan 24, 2019
End Date: Jul 23, 2020
Objective 1: Characterize the spread of trunk pathogens and other wood-infecting fungi of grape, at the plant, field, and landscape scales. Subobjective 1.A. Evaluate alternative hosts as inoculum reservoirs. Subobjective 1.B. Define the stages of wood colonization, in terms of the infection process and the plant response to infection. Objective 2: Identify the physiological and genetic bases of grapevine resistance to abiotic and biotic stresses using a combination of advanced-imaging methods, nucleic acid-based analyses, light and confocal microscopy, and hydraulic physiological measurements. Subobjective 2.A. Determine how drought stress alters the hydraulic permeability of grapevine root systems and the capacity for hydraulic redistribution among grapevine rootstocks. Subobjective 2.B. Determine the roles that xylem network connectivity, cavitation, and embolism repair play in drought resistance of grapevine rootstocks. Objective 3: Characterize the relationship between vineyard floor management practices (including, but not limited to, sustainable weed management) and biogeochemical cycles. Subobjective 3.A. Quantify greenhouse gas emissions resulting from current vineyard floor management practices, to refine existing biogeochemical models. Subobjective 3.B. Examine soil microbial communities associated with vineyard floor management, and edaphic and environmental gradients. Subobjective 3.C. Examine weed communities associated with vineyard floor management, and edaphic and environmental gradients to develop ecologically-based weed control strategies.
Objective 1, Subojective 1.A. - Compare population genetic diversity, host specificity, and spore dispersal of E. lata among three hosts (grape, apricot, willow), in CA landscape that include vineyards, stonefruit orchards, and riparian areas. Subobjective 1.B. - Identify unique plant-molecular responses in leaves, which coincide with the early stage of canker development, and to then develop a PCR-based assay for these plant molecular responses for use as an early detection tool. Objective 2, Subobjective 2.A. - Combine hydraulic physiological measurements with anatomical assessments to determine how stress and rootstock genotype affect the hydraulic permeability of roots. Subobjective 2.B. - Use HRCT to evaluate the structure and function of grapevine xylem. Objective 3, Subobjective 3.A. - Assess the effects of pulse events (fertigation or irrigation of equal volumes in the ‘in-row’ region, 70% regulated deficit irrigation; tillage or no tillage in alleys) on CO2 and N2O emissions. Subobjective 3.B. - Soil samples will be extracted, quantified and pooled to link landscape patterns of soil microbial communities and specific populations (e.g., nitrifiers, denitrifiers) with functions that facilitate winegrape production, specifically transformations that control nutrient availability to plants and GHG emissions. Subobjective 3.C. - Survey weed communities in the Napa AVA up to 90 existing field sites for which grower interviews and soil data exist.