A Cornell-grown apple rootstock is showing promise at reducing the impact of harmful bacteria. Professor of horticulture at Cornell University, Terence Robinson: “Most people don't realize that an apple tree is composed of two varieties. The variety that has the fruit above ground and the second variety for what we call the rootstock.” The two are joined near the ground by a graft union between the variety of apple tree that produces fruit and the rootstock.
Geneva, the rootstock developed and patented by Cornell University, has been modified into 15 different versions to help certain apple trees with a host of issues, including fire blight. Robinson: “When a tree gets infected with fire blight bacteria, it affects the blossoms, but the bacteria then gets into the tree and is moved down until it hits the rootstock then it kills it. Without the rootstock, the tree dies.”
The Geneva apple rootstocks that are resistant to fire blight allow growers to trim off areas of a tree that are infected with the bacteria instead of the bacteria killing the entire tree. Thanks to these rootstocks, apple growers have adapted to growing dwarf trees that are smaller in stature but produce the same size and amount of fruit. By doing so, they are able to grow more bushels per acre.
“They’re all resistant to fire blight, they’re all very productive, and they’re all dwarfing to different degrees,” Robinson said. The three new rootstock varieties released in 2023 address issues for Snapdragon trees, help organic apple growers, and the third strengthens graft unions.
Source: spectrumlocalnews.com
