Other Breeding Programs
While only 14 varieties are or have been for sale in the US, there is on-going breeding of columnar trees. Here, Cornell is doing some work. Most breeding is in Europe. I would expect those from Russia and Lithuania to be very cold hardy if we could get access to them.
Cornell should have some columnar releases in the future. The head of Cornell's breeding program, Dr. Susan Brown, has discussed that they have columnar crosses with 12 species. By species, she is not referring to common apple but the native Malus species from around the world collected for breeding research. Along with dwarf offspring, she noted some turned out viney. She also noted that as high as 25% of the resulting seedlings have a genetic defect called Pale Green Lethal (PGL) that affects photosynthesis.
Most columnar apple breeding is taking place in Europe. I spent many hours searching the web, doing google translations, and looking at European plant breeder's rights filings and trying to cross-reference things. There may be some duplicates if the larger distributors sell under their own name like Stark does in the U.S.
Institute of Expermental Biology (UEB), Czech Republic. Already discussed is the Institute of Experimental Botany in the Czech Republic that created the 4 Urban Apple varieties and have a dozen columnar releases. I should note that I have seen the Tasty Green with two different research designation, UEB 3812-2 and AK-98. The UEB comes from the Czech program. The AK is more like those from the Geisenheim, Germany breeding program.
Research and Breeding Institute of Pomology, Holovousy, Czech Republic.
4 columnar varieties. Kordona is Wijcik x Florina and Cumulus is Selena x Wijcik. 2 crosses of Telamon (Ultra Spire) with Florina are Herald and Slendera. Slendera is the variety shown in the first post of this thread. This program also released Pidi which is sometimes marketed as columnar but is just a very weak vigor variety.
University of Novi Sad, Serbia. 6 crosses released and found for sale in Europe. These are all Wijcik crosses. 2 with Granny Smith, 1 with Golden Delicious, 1 with Prima, and 2 with Ida Red. N
ote that Granny Smith is a triploid which means it has 3 sets of chromosomes instead of the normal two (diploid). Triploids are usually said to be pollen sterile so you need two diploid trees planted with a triploid to ensure pollination of all 3 trees. The seeds from a triploid will often have problems with viability and growth. For those that germinate and grow, many will have genetic deformities. But it is possible to get functioning apple trees from a cross with a triploid.
Research Institute Geisenheim, Germany. Has released 2 series of columnar trees. Based on the research designations, the crosses occurred in the mid to late 1990s and plant rights filings were made from 2004 to 2009. All are crosses with the Spire series. Mostly crossed with European apples like Elstar and Topaz. Topaz is a scab resistant variety developed by the UEB in Czech R.
The 6 trees of Pom series (Pomforyou, Pompink, Pomredrobust, Pomfital, Pomfit, Pomgold). 3 of these were also marketed under names from King Arthur.
The 5 trees of the Cats series (Goldcats, Greencats, Redcats, Starcats, Suncats). Cats stands for columnar apple tree system.
Russia, Lithuania, Latvia, Poland. I found 29 trees coming from these areas but it was hard to find much out about them, sometimes just a nursery listing (Like this with about 20 varieties,
http://www.vitaflora.lt/en/by-plant...by,product_name/results,31-130?language=en-GB). I would guess the Russian trees are pretty cold hardy. For the Russian trees that I found breeder/variety rights, those filings date to from 2002 to 2005. The Russian variety Arbat has been called the first scab resistant columnar release. I would guess their breeding program ended as I could not find them on the web. Some of these Russian trees were picked up and marketed by a large German wholesaler, Kraemer. The Lithuanian Institute of Horticulture is activeand has releases with variety rights filings from 2009 to 2012. I could not find information on their releases but they have been publishing interesting papers on columnar trees. I found the paper that measured growth in the nursery on various rootstocks to be helpful. I found some Latvian research papers on columnar but no releases. 1 apparent Polish release. A number of those from this region I only know from the nursery listings.
Large Nurseries: Nursery George Delbard in France and Lubera of Switzerland. I do not know if these are rebranded like Stark does or not. It seems that Delbard does their own breeding. The only Lubera variety that had breeder's rights pointed to a Dutch research institute.
Delbard filed breeder's rights on 2 of their 11 columnar releases. Most of the Delbard trees have a Delbard name, a French marketing name, and an English marketing name. For example, decloti/Red River/Villandry are all the same. Of the 11 varieties, 6 still appear on their website (
http://www.georgesdelbard.com/CT-790-pommiers-colonnaires.aspx). The Delbard trees appear to be true columnar trees.
From Pillnitz in Dresden Germany, I found a series of 4 trees that are called columnar but appear to be just low vigor spur type trees.
