Our long-term goal is to extend the longevity and productivity of vineyards and orchards by developing a suite of detection tools, economic data to demonstrate the cost effectiveness of preventative practices, and resistant plant material for replanting diseased vineyards and orchards. Wood-canker diseases significantly limit the profitable lifespan of vineyards and orchards. Annual yield losses due to Eutypa dieback and Botryosphaeria dieback, two widespread wood-canker diseases of grape (aka trunk diseases), account for 14% of the gross producer value of CA wine grapes. Trunk diseases eventually infect every vineyard in CA and are the main depreciable driver of vineyard longevity. Annual yield losses of CA pistachios to Panicle blight are reported to be 20 million lbs. In almond, they attack the trunk and the base of major limbs. Yield losses accumulate each year, as there are no effective methods to eradicate the wood infections. As such, diseased orchards and vineyards must be replanted on a truncated cycle, and the high start-up costs are not repaid. Therefore, the best strategy is prevention.
CA is the ‘sole producer’ (³ 99% of US production) of almonds, pistachios, and raisin grapes, and leads the nation in production of table grapes and wine grapes. These US commodities must maintain a consistently high level of quality to ensure their dominant position in the world marketplace. Wood-canker diseases that threaten the long-term viability of vineyards and orchards continually challenge this goal. Wood-canker diseases are a threat beyond CA, too, as evidenced by invited presentations to members of our research team from other states (e.g., Washington Assoc. of Wine Grape Growers).
In 2011, we were awarded an SCRI Planning Grant, which brought together industry representatives and a new, diverse research team of plant and social scientists, to help tackle wood-canker diseases from various fronts. In 2012, we were awarded a two-year SCRI Standard Research and Extension Project (SREP). At our 2014 annual meeting, the Advisory Board and research team reviewed progress to date and came to a consensus on the following proposed objectives, projects, and hypotheses for 2014-2017:
Objective 1. Develop new detection tools.
Project 1a. Rapid detection tool for spores in the field, combined with new molecular markers for spore DNA, to reveal wood-canker pathogens in young plantings.
Project 1b. Non-destructive detection tool for early infection in apparently-healthy plants, to identify and remove infected nursery stock.
Project 1c. On-line, searchable DNA sequence database of 200 strains of wood-canker pathogens, for accurate diagnosis of wood-canker diseases.
Objective 2. Develop and deploy new extension tools that increase adoption of preventative practices in young orchards and vineyards.
Project 2a. Identify the economic hurdles to adoption.
Project 2b. Identify the sociological hurdles to adoption.
Project 2c. Develop new extension tools.
Objective 3. Identify sources of wood-canker disease resistance in the germplasm.
Project 3a. Identify resistant grape germplasm.
Project 3b. Identify resistant pistachio and almond germplasm.
Project 3c. Identify biochemical and anatomical markers of resistance, to compliment breeding programs for new cultivars of grape, pistachio, and almond.
These broad-ranging objectives address complex research questions that span cropping systems, and intertwine the social and plant sciences. They are thus not likely to be funded by commodity boards as annual grants to individual researchers. These objectives address the most significant gaps in knowledge, the absence of which hampers numerous short-term projects (e.g., combining mechanized pruning with fungicides labeled for spray applications). Collectively, these objectives bring novel genetic, social, economic, and biological dimensions to research on wood-canker diseases, in order to make substantive advances.