Project Number: 2094-21220-002-12-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2016
End Date: Aug 31, 2019
National and international rootstock breeding programs are developing new rootstock genotypes with novel traits that have the potential to increase the sustainability and profitability of the U.S. industry. There is a well-established national breeding program that is developing new apple rootstocks jointly run by USDA-ARS and Cornell University at Geneva, NY. Any newly developed rootstock must be evaluated for a range of characteristics and in a range of climates to fully understand its advantages and weaknesses. To accelerate future rootstock development and to understand the capabilities of current rootstock there is a strong need to understand the physiological and genetic basis of new rootstock performance and the potential interactions with scion cultivars. In modern orchards rootstocks need to interact are subjected to with numerous biotic and abiotic stresses in the orchard including (rhizospheric pathogens, climate change, water availability, soil pH and fertility) which end up affecting not only tree productivity, but also the quality of fruit being harvested. It is critical that we understand how different rootstocks respond to biotic and abiotic stresses to develop recommendations for use under certain orchard conditions. As such, we propose to: 1. Accelerate the development of new improved apple rootstock genotypes with critical traits for advancing tree fruit production. 2. Accelerate critical evaluations of new apple rootstock genotype’s adaptability to important and diverse environments, pests, production systems and propagation systems including a) climatic adaptations, b) abiotic soil adaptations, c) rhizosphere biotic soil adaptations and pests, d) nutrient uptake efficiency, and e) impact on fruit disorders. 3. Evaluate the economic and sociological impacts of adopting new apple rootstocks for fruit production including impacts on the environment and on labor, and 4. Initiate rapid and effective extension and outreach efforts to disseminate objective information about new apple rootstock traits and their successful management in competitive production systems.
The development of apple rootstocks will be led by the Geneva apple rootstock-breeding program using marker-assisted selection. This project will provide critical new phenotypic data on important rootstock traits that have not been genetically characterized because they require intensive effort (rhizosphere biotic relations) or extensive evaluations (field trial years), allowing the development of new predictive molecular markers for selection of new rootstocks optimized for localized performance. Some of the markers to be used will be developed with this project. Rootstocks of all three species will be evaluated in replicated field plantings in various climates for survival, yield, fruit quality attributes, leaf and fruit nutrient uptake, replant disease tolerance with a focused effort on the rootstock x rhizospheric biota relationships, winter hardiness soil adaptability and virus susceptibility. The economic/sociological component of this research will comprise two inter-related goals. First, we will develop a careful analysis of the costs and benefits to producers for various rootstocks across orchard systems. We will conduct this analysis considering a 25-year time horizon considering projected yields and input usage over that time, and then use this information to calculate the expected internal rates of return for the various rootstock options. Second, we will conduct a detailed analysis of the economic impacts of the various rootstock options on labor usage and labor costs for the tree fruit industry. This analysis will consider the feasibility of adopting different types of harvest mechanization tools for the various rootstock options, and will shed additional light on the economics of introducing new rootstocks in tree fruit production in the United States. The sociological barriers to new rootstock adoption will be evaluated by surveying fruit growers and nursery operators to study the hurdles to adoption of new rootstocks The extension and outreach component will have a national focus and will leverage work already done on the apple rootstock extension website. It will also utilize all the participants in the NC-140 project to reach fruit producers in each fruit producing state.