Three new apple rootstocks bolster Geneva’s program

A rootstock developed in the Geneva program. Photo by Allison Usavage

 

“I think we have close to 70 million trees planted on Geneva rootstocks around the world,” said Gennaro Fazio, adjunct associate professor of horticulture in the College of Agriculture and Life Sciences (CALS). “Typically, we are planting somewhere between 5 million and 7 million trees a year in the U.S. alone.”

Those numbers will grow with the release of three new rootstocks – Geneva 257, Geneva 484 and Geneva 66, all licensed through the Center for Technology Licensing at Cornell after 40 years of testing. Geneva is a registered trademark.

“Geneva rootstocks have become a worldwide phenomenon in apple growing,” said Terence Robinson, professor of horticulture (CALS). “The word ‘Geneva’ is so internationally known when it comes to apples that we’ve branded the program.”

Robinson said the three new rootstocks offer something for almost every apple grower.

Geneva 257 is a semi-dwarfing rootstock that imparts large fruit and high crop load in varieties such as SnapDragon or Gala, allowing for more high-density orchards with larger fruit. Geneva 484, another semi-dwarfing rootstock, is also highly productive and yield-efficient.

Fazio calls Geneva 66 a “mixed bag” – it’s a semi-dwarfing, red-leafed and productive rootstock, resistant to fire blight and likely to be popular among cider-apple growers who mechanically harvest their trees.

“These are now part of a stable of rootstocks that growers can pick from for their specific situation,” Robinson said. “If you’ve got sandy soil and you’re an organic grower in Washington, you’re probably going to pick Geneva 484. If you’re an apple cider grower in Vermont and you are going to shake the trees to harvest, you probably want Geneva 66. And certainly if you’re a SnapDragon grower, we are telling them to pick Geneva 257.”

The Geneva Apple Rootstock program dates back to 1968. Fazio and Robinson credit two of the program’s pioneers: CALS apple rootstock breeder Jim Cummins and plant pathologist Herb Aldwinkle.

“Jim had this idea to develop new rootstocks for apples that could be both dwarfing but also resistant to fire blight,” Robinson said. “Growers needed a place to go for replanting orchards devastated by fire blight and by cold damage, and these Geneva rootstocks have been sort of a salvation.”

Said Fazio: “Herb was instrumental in the selection of resistance to root diseases and fire blight. If we didn't have those initial crosses, and the work and the vision to make a difference, our industry would be in trouble right now."

Fazio and Robinson are now looking to the future.

“We have to think about the next 50 years, maybe the next 100 years, because it takes so long to develop these rootstocks,” Fazio said. “We are trying to find out which rootstocks are more tolerant to salty water, because salty water is associated with drought. We also have to consider climate change.”

Robinson said that work will include improving on the new rootstocks. To that end, Fazio and Robinson hope a new class of scientists can carry on their work.

“Now we try to improve on the rootstocks we have released so far and get rid of the weaknesses they each have, and that will be a continuing process,” Robinson said. “I hope there are other scientists that find this work interesting and it continues, because rootstocks turn out to be such a key component of an apple orchard.”

Mike Hibbard is a freelance writer for Cornell AgriTech.

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