A group of scientists from around the country aims to develop new tree fruit rootstocks for the tree fruit industry with the goal of increasing orchard profitability. The group, which calls itself Root2Fruit, plans to submit a proposal in 2012 to the U.S. Department of Agriculture for funding through the Specialty Crop Research Initiative. The group includes networks of researchers from a number of institutions who will join forces to develop rootstocks for apples, pears, peaches, nectarines, plums, and cherries and help make them available to growers. They hope that the results of the four-year project will have a significant impact on the tree fruit industry within the next ten years.
Dr. Gennaro Fazio, plant geneticist with the U.S. Department of Agriculture in Geneva, New York, said the newer rootstocks already in use—from dwarfing apple rootstocks to nematode-resistant peach rootstocks—have boosted orchardists’ profits by many millions of dollars in recent years.
For example, between 12 and 17 million apple trees are planted each year, of which 92 percent are dwarfing rootstocks. Without those rootstocks, there would be no tall spindle systems or fruiting walls, and yields would be lower than they are today. Fazio said a conservative estimate of the value of the increased production from the use of dwarfing rootstocks is half a billion dollars annually.
Rootstocks with resistance to fireblight also have the potential to generate impressive returns. Fazio estimates losses of trees to fireblight cost U.S. growers $10 to $50 million annually. The potential gains in just one year from using the fireblight-resistant Geneva rootstocks would be enough to cover the entire cost of Cornell University’s fireblight-resistant rootstock breeding program since its inception in 1968, he estimates.
Fazio said he is confident that the Root2Fruit group project could have an even greater financial impact.
“Can we increase profitability of the industry by $750 million a year? I think so,” he told members of the International Fruit Tree Association at their annual meeting in Pasco, Washington, in March. “I think for every dollar we put into rootstock research we’re going to get ten times that. We’re trying to get more money leveraged from federal funds to make a difference to your bottom line.”
The idea for the project came from a meeting of scientists involved in the NC 140 Regional Rootstock Research Project in 2008, Fazio said. The group has for many years been evaluating rootstocks for survival, size, and yield efficiency, but recognized the need for further research on rootstocks. It envisioned an effort along the lines of RosBREED, whose goal is to harness the power of genetic information to speed up the breeding of new fruit varieties.
The group applied for a planning grant, and scientists from around the country held an organizational meeting in 2010 and adopted the name Root2Fruit for the new project.
During a discussion of the project at the International Fruit Tree Association’s annual conference this year, Greg Reighard, environmental horticulturist with Clemson University, in South Carolina, said that with the peach genome now completed, breeders can more easily identify appropriate parents, and marker-assisted selection can be used to identify desired traits in offspring. With the cost of biotechnology dropping tremendously, progress should come much more rapidly.
He hopes that the Root2Fruit project will do for rootstocks what the RosBREED program is doing for scions and facilitate the transfer of technology at minimal cost to breeders and stakeholders.
Rachel Elkins, University of California farm advisor for Lake and Mendocino counties, said research on a number of pear rootstocks is being undertaken around the world, and she hopes that the Root2Fruit project will be able to gather information from other areas so that scientists can work together to develop adequate rootstocks for everyone.
The Root2Fruit planning team is writing a white paper and analyzing where the research dollars could make the most difference for the tree fruit industry. It is seeking input from nurseries, growers, and industry groups, and looking for growers willing to host field trials.
Priority research areas already identified include: improved propagation techniques; integration of rootstocks into management systems; root and soil interactions; localized, web-based rootstock information; identification of rootstock traits that impact sustainability; and faster selection of improved and dwarfing pear rootstocks.
IFTA members provided their priorities through an instant survey during their conference in Pasco, Washington.
Research areas that a majority of growers considered critical were:
- Size-controlling rootstocks (84% of respondents)
- Information on resistance of existing rootstocks to various pests and diseases (72%)
- Rootstocks to mitigate replant disease or other root diseases (70%)
- Basic genetic research to improve the propagation, dwarfing, precocity, and disease resistance of rootstocks (64%)
- Adaptability of rootstocks to different climates in terms of ability to tolerate heat stress or cold weather (58%)
- Of least importance to growers were localized Web-based information tools for selecting and planting rootstocks, and information on the economic impacts of using rootstocks to improve the fruit mineral content (for example, zinc) for human nutrition.
- Seventy-seven percent of the respondents were apple growers, 16 percent cherry growers, 5 percent soft fruit producers, and 2 percent pear growers.