Pacific Crabapple Project

The Pacific Crabapple Project

Native Apple Rootstock Research and Development

With support of the Western Sustainable Agriculture Research and Education (SARE) program, we are excited to announce the launch of an on-farm research project that could hold the promise of new rootstock options for apple production – including options with greater disease resistance, tolerance for wet soils, and climate adaptability! Watch this page for regular updates on this project.

(Photo by Gordon Leppig and Andrea Pickart)

 

Why We Need a Rootstock Revolution

October 29, 2017

Grafting apple trees onto specific rootstocks for size control, early bearing, and pest and disease resistance has been practiced for hundreds of years. Ultimately this practice was formalized in Europe during the mid-1800s with the selection of specific named (or more accurately, numbered) rootstock cultivars. By the 1970s and 80s apple rootstock development peaked with research programs in new regions including Russia and the United States (notably from the Cornell/USDA research station in Geneva, NY).

Despite this work, today the diversity of commercially available rootstocks remains

extremely limited. Practically speaking, the most widely available options are the Geneva selections, the Malling (England) rootstocks, or the Russian BUD rootstock series. This represents rootstocks selected at only 3 locations, optimized for 3 climates, 3 soil types, and common production challenges found in 3 regions.

While good efforts have been made to evaluate the adaptability of rootstocks beyond the original research stations where they were selected, additional screening usually takes place within regions where the apple industry is already well established (and where previous Geneva, Malling, and Russian rootstocks were already successful). This process does little to expand the range of rootstock options for new regions and new climates.

The result is that aspiring apple growers are often forced to artificially re-create optimal growing conditions for the rootstocks available to them. Irrigation systems, drain tile, even the placement of apple trees on elevated beds are just a few of the common ways farmers modify land to sustain non-locally adapted rootstocks.

We believe this approach is fundamentally flawed. Rather than altering land and water to meet the needs of a crop, an agro-ecological approach should call for planting crops that are already adapted to the local landscape and the local climate. This project was launched as with the intention of developing precisely such an option for the maritime Pacific Northwest.

Six species in the Malus genus are native to North America. In the western United States this includes Malus fusca (the Pacific crabapple), a species that is abundant in maritime climates extending from Alaska to Northern California. Unique among apple species, Malus fusca exhibits a wide-range of adaptability to common maritime site conditions: thriving in hydric and wetland soils (including saltwater estuaries), as well as in heavy clay soils, and poorly drained upland sites. It is considered a keystone native species in both high rainfall climates such as coastal mountain rainforests, and in lowland rainshadow environments such as the Puget Sound ‘banana belt’ where local rainfall averages may total less than 20 inches annually.

For at least two decades a handful of amateur pomologists and backyard orchardists in the Northwest have dabbled with the use of Malus fusca as a rootstock for table apple varieties. Anecdotally, these novelty grafts have been largely successful, apparently thriving even in conditions where traditional apple rootstocks do not, such as wet meadows. Unfortunately there is no actual research demonstrating how widely compatible Malus fusca is with various apple varieties.

Through this project we are establishing a replicated research block of Malus fusca rootstocks, testing more than two dozen apple varieties for grafting compatibility over a three-year period (with additional traits, such as suckering, evaluated in future years).

Continue to watch this page for more project details, updates, and extended information on the ecology of Malus fusca.

 

 

Orchard Block Site Preparation Begins

October 30, 2017

We’ve been working diligently at the farm to prep our research block planting area. The first step was some extensive brush hogging and mowing of an abandoned pasture area. In the weeks and months ahead we will be getting the deer fence installed, laying out the rows, and removing the existing vegetation (replacing it with a native grass/forb understory to support beneficial insects, pollinators, broader biodiversity).

Interestingly, there are several wild Malus fusca in the hedgerow around the planting area so we know the species is well adapted to the site. This removes one variable from the study, although we will maintain a control group of non-grafted Malus fusca trees in the orchard block which will allow us to compare the growth potential against the grafted trees.