Start Date: Mar 01, 2012
End Date: Jan 23, 2014
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.