Location: Crops Pathology and Genetics Research2013 Annual Report
1a. Objectives (from AD-416):
1. Develop sustainable disease control practices for grapevines. [NP 303, C3, PS3B] 2. Develop sustainable vineyard floor management practices for vineyards. [NP 305, C1, PS1B.1] 3. Develop sustainable water management practices for vineyards. [NP 305, C1, PS1B.1] 4. Investigate the impacts of vineyard practices on soil microbial ecology. [NP 305, C1, PS1B.1]
1b. Approach (from AD-416):
1. Characterize the infection process of grapevine roots by the fungal pathogen Armillaria mellea, the causal agent of Armillaria root disease; Characterize the significance of riparian areas in the spread of Pierce's disease. 2. Identify differences in regional populations of Conyza canadensis, cover crops that effectively compete with C. canadensis, and the effects of soil resource availability on competition between cover crops and C. canadensis; Identify cover crops that effectively compete wtih problematic weeds. 3. Evaluate the interactive effects of irrigation practices and vineyard floor management practices on grapevine yield, growth, physiology, and nutrition. 4. Examine the effect of cover crop functional type on soil microbial communities and microbially-mediated soil processes; Characterize rhizosphere communities associated with Vitis rootstocks; Examine the impacts of vineyard floor practices on mycorrhizae. REPLACING 5306-21220-004-00D (03/12); 5306-21220-003-00D (01/07)
3. Progress Report:
Winegrapes, table grapes, and raisin grapes grown in California represent over 90% of U.S. production. Maintaining a competitive edge with worldwide producers is crucial. In order to minimize production costs and maximize vineyard productivity, discovery of sustainable vineyard practices for control of trunk diseases, weed management, greenhouse gas emissions, and irrigation is paramount in the grape industry. This need is driven by more stringent environmental regulations, the increasing interface between urban and agricultural areas, and the decreasing availability of water in the western US. In FY2013, our first objective addressed the spread of trunk diseases (Phomopsis dieback and Botryosphaeria dieback), both at the cellular scale and at the vineyard scale. Our findings from objective 1 experiments have applications to the management of trunk diseases, namely regarding the need for pruning-wound protectants in eastern US vineyards. The second and fourth objectives examined biological, edaphic, and management-related drivers of greenhouse gas emissions, soil microorganisms that mediate biogeochemical transformations, and weed establishment, to develop practices that reduce environmental inputs and also the economic costs of grape production. To address objectives 2 and 4, we tracked the energy use and environmental impacts of winegrape production using Life Cycle Assessment, and examined winegrape production areas and the surrounding wildlands for carbon storage capacity. These measurements are critical for the development of national and international environmental policies, which will establish contributions and offsets to global warming potential, energy use, direct water use, and the U.S. Environmental Protection Agency's criteria air pollutants for many different sectors of the US economy. The third objective integrated physiological and genetic approaches to develop grapevines that are resilient in the face of abiotic stresses. To address objective 3, we evaluated drought resistance of grapevine rootstock materials by assessing water uptake potential of fine roots subjected to stress and using high resolution computed tomography (HRCT) to evaluate susceptibility to embolism formation and the ability to repair blocked vessels across grapevine rootstocks. Water use is and will forever be an important priority for US grape growers, particularly in the arid western states, where grape production is dependent on irrigation. Growers require plant material that can better resist drought conditions.
Baumgartner, K., Fujiyoshi, P.T., Travadon, R., Castlebury, L.A., Rolshausen, P.E. 2013. Characterization of species of Diaporthe from wood cankers of grape in eastern North American vineyards. Plant Disease. 97:912-920.