Research Accomplishment Reports 2010

Improving Economic and Environmental Sustainability in Tree-Fruit Production Through Changes in Rootstock Use

D. Archbold
Department of Horticulture

 

Non-Technical Summary

The information developed through this project is vital to the economic success of the North American fruit industry by preventing mistakes by the industry and identifying rootstocks that are more productive and thus more profitable than existing rootstocks. This project has already become the primary source of information on rootstocks for the North American tree-fruit industry in each fruit production region of the continent.

The primary outputs of this project have been and will continue to be unbiased information on the field performance, stress tolerance, and propagation of fruit tree rootstocks in different climates and soils across North America. This is measured by the continued flow of information to fruit growers and nurserymen through both oral presentations and publications from each of the uniform multi-state orchard plantings and from rootstock development and evaluation work done by the individual cooperators.

Since the last project revision, this project has published 17 refereed reports on nine multi-state rootstock trials. Publications from individual researchers or groups or researcher under the objectives of this project are also an important measure of success, and since the last rewrite of this project, there have been more than 140 publications by individual researchers.

Outcomes or projected Impacts: The expected outcome of this project is a more profitable and competitive tree fruit industry in North America. To remain competitive in the world fruit market, fruit growers need to replant old orchards, but the high level of investment required and the long-term nature of the investment to plant new orchards require that growers make sound research-based decisions of which rootstock and cultivar to plant. If the wrong rootstock is used, it can result in low production and reduced profitability or in the worst case, death of the trees and significant economic losses. If superior rootstocks are used, yields, fruit quality and hence profitability can be improved. As results from this project are made available, the fruit industry has made and will continue to make changes in the rootstocks used.

The impact of this project will be measured by the changes the fruit industry makes in adopting new improved rootstocks and by the prevention of serious rootstock failures and associated economic losses. This will be measured by surveying rootstock propagation nurseries to determine trends in which rootstocks are being planted by North American fruit growers. In addition, data from the National Agricultural Statistics Service http://www.nass.usda.gov/Census of Agriculture/index.asp is analyzed to determine planting trends. The Census of Agriculture is published every five years and contains valuable data. This is then incorporated into our impact statements. Impacts are posted on our website http://www.NC140.org

Many individual states also conduct tree fruit planting surveys periodically that are utilized to track planting trends of dwarfing tree fruit rootstocks and will be utilized to measure the impact of NC140 in individual states.

2010 Project Description

Four plantings are being studied for gaining knowledge about the effect of rootstock on long-term fruit tree growth and yield. The 2002 apple rootstock trial compares Buckeye Gala on nine rootstocks. The 2003 apple rootstock and physiology trials evaluate Golden Delicious on eleven different rootstocks. A companion physiology trial consists of Golden Delicious on 3 rootstocks with trees thinned differentially to determine if prior year crop load affects fruit set. The 2009 peach rootstock and physiology trials consist of Redhaven peach on fourteen different rootstocks and a companion physiology planting with the same objective as for apple above. The 2010 apple rootstock trial consists of Aztec Fuji apple on thirty-one different rootstocks. Each planting will be studied for 10 years or more.

The detailed and objective evaluation of these rootstocks provides growers with the information needed to select the most appropriate rootstocks for their needs as they become commercially available in the future. The NC-140 trials are regularly used as demonstration plots for visiting fruit growers, extension personnel, and research scientists, and the Kentucky results are presented at a national meeting with results from all participating states with the same plantings.

2010 Impact

The 2002 and 2003 plantings have reached a point where the rootstocks have clearly differentiated so that the better ones, with less growth and higher yield of quality fruit, can be identified. However, final conclusions from which recommendations to commercial fruit growers can be made are a few years away. The 2009 and 2010 plantings are established and growing well. Yield data will be collected in the future.

 

2010 Publications

Robinson, T., D. Wolfe, J. Masabni, R. Andersen, A. Azarenko, J. Freer, G. Reighard, P. Hirst, D. Hayden, B. McCluskey. 2010. Performance of Plum Rootstocks with Stanley, Valor, Veeblue, and Santa Rosa Scions in the 1991 NC-140 Multi-State Plum Trial. Journal of American Pomological Society 64(3):173-182.

Wolfe, D., D. Archbold, J. Johnston, and G. Travis. 2010. Rootstock and Interstem Effects on Pome Fruit Trees. 2010 Fruit and Vegetable Crops Research Report. University of Kentucky College of Agriculture, Agricultural Experiment Station publication. PR-608. pp.14-16.