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geneva curveballs

Posted by Michael Phillips 
geneva curveballs
May 17, 2018 04:03PM
New rootstock selections go through all sorts of testing before being released ... but then comes the REAL TEST as growers experience whatever results at different locations over the years. This thread is a dialogue for assessing the challenges in the Geneva Rootstock lineage.

The issue with latent virus springs from nurseries and growers alike using "dirty wood" when grafting onto Geneva stock. I've been told that the fact that nurseries and growers have ignored the advice to use virus free scions is not the fault of the rootstock, it is the fault of the end user. People have reported issues down the road with G.935 and G.202 in this regard; I saw four Macouns on G.30 shrivel up and die a couple years ago. Perhaps someone might start a separate discussion on virus-free scions as I do not know how the average joe goes about achieving that recommendation.

Some rootstocks tend to not shut down early which can lead in turn to winter injury some years. G.16 has been observed to keep going longer into the fall with respect to the same variety on neighboring rootstocks. But just as pertinently, let's note that growers need to tame down nitrogen before terminal bud set, lessen irrigation heading into fall, and not be pruning in the harvest months.

Now for the issue that has precipitated this discussion on my part. And that's death of the cultivar after the first year of planting in colder zones. Someone in the upper Midwest reported losing new trees on an assortment of Geneva stock the previous spring. Bummer indeed. The 2017 season was marked by a very warm fall followed by unusually deep cold in the second week of November and then even sub-zero nights by early December. This spring I have fourteen dead trees on a mix of Geneva stock; the cambium is brown and gooky and the cultivar is totally gonesville. The rootstock tissue from the bud union down appears to be alive. Meanwhile, other new trees planted last year on MM.106 and Bud.118 and Antonovka are popping bud and dancing in the sunshine. Same orchard, same cold, same guy.

Here's the list of what succumbed, not that I think all these cultivars are necessarily the weak point in this train wreck:
2 Bramley's Seedling - G.202
2 Calville Blanc - G.935
2 Porter's Perfection - G.202
2 Reinette Zabergau - G.935
2 Roxbury Russet - G.202
4 Suncrisp – G.30

Nurseries that turbo-charge growth can set up this sort of dynamic. Similarly, there are good reasons not to overdo nitrogen on the farm that very first season a new tree is in the ground. That's not the case here in either respect. In fact, the Harrison cider apples that I planted on MM.106 came from the very same nursery. Similarly, the new trees planted out here in Lost Nation over the previous decade on assorted Geneva rootstock are doing great. I especially like the looks of Winecrisp on G.890 and Crimson Crisp on G.202 going into 3rd and 4th leaf respectively. What happened above is a function of that warm fall/ quick cold scenario. But why did only the Genevas die?

Please share what you've been seeing with regards to these rootstocks.

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 1 time(s). Last edit at 05/22/2018 04:44PM by Michael Phillips.
Re: geneva curveballs
May 17, 2018 04:31PM
This is what I know:

1. All Geneva rootstocks appear to be hypersentive to common apple viruses. We're not getting straight answers out of Cornell.
2. There is a "new" virus out there that is showing up in NY orchards, but that is not "commoon" to apples - that is, luteovirus Luteovirus
3. G16, G41, G935, G890 - all seem to be the most problematic either in the nursery (e.g., G41, G935) but also in the field.
4. It seems that G11 and G30 are the least problematic based on reports I have heard. and what I have seen.
5. I don't think their sensitivity to decline is related to cold damage, though that could play a role and reducing N and other vigor enhancing activities is critical.

There is no practical way to clean up dirty wood for all the cider varieties out there. Too expensive. You can't even get certified virus free scionwood for commercial dessert fruit varieties. Rarely. Plus management activities can allow for reintroduction of viruses if aphids and leafhoppers become overactive and hop from infected wood to clean wood - so virus free doesn't probably matter in most locations.

Ike mentioned at Stump Sprouts within the past few years that he felt it was the Robust 5 that the weak link in the Geneva rootstock series. I've never read or seen anything that verifies that, but it would be interesting to find out more.

Basically, I am telling anyone that puts any variety that can be considered dirty/virus-laden wood on Geneva rootstock, to be prepared. Instead I am suggesting that any cider apples go on MM111 or M7 and plant them tight to get dwarfing. How tight? 6-8' depending on your capacity for a wild ride. I know Steve Wood plants his tighter that than, but again he is in a colder climate and so the warmer it gets (climate wise), you need to be a bit more conservative.

Mike Biltonen, Know Your Roots
Zone 5b in New York
Re: geneva curveballs
May 17, 2018 06:19PM
Michael Phillips Wrote:
-------------------------------------------------------
> Here's the list of what succumbed, not that I think the cultivars are necessarily the weak point in this train wreck:
> 2 Bramley's Seedling - G.202
> 2 Calville Blanc - G.935
> 2 Porter's Perfection - G.202
> 2 Reinette Zabergau - G.935
> 2 Roxbury Russet - G.202
> 4 Suncrisp – G.30


Well, Michael, in my opinion you might be pulling things a bit there.
I can tell you that here in Quebec, Bramley, Calville blanc, Zabergau and Roxbury all died from lack of winter hardiness.
Porter's Perfection survives but is obviously at the limit of its hardiness, with lack of vigor, lack of productivity, and underpar fruit quality.
Suncrisp I haven't tried.

So if you add-up marginal winter hardiness of the varieties, with succulent 1st year growth and a few adverse meteorological factors that may enhance some vulnerabilities with the Geneva stocks, I guess this is the result...
Claude

Jolicoeur Orchard
Zone 4 in Quebec
Re: geneva curveballs
May 17, 2018 08:19PM
Just the nudge I needed, Mike . . . now putting in four Macoun on MM.111 on 8 foot spacing to replace the Suncrisp that replaced the G.30 version of Macoun in this row. A nice progression here of musical apple trees, methinks. We should start a thread on Vigorous High Density to keep tabs on grower experience in this bold direction.

As for cultivar hardiness . . . Bramley's Seedling and Calville have been in my orchard going on ten years or so; Porter's and Zabergau live as grafts on test branches; admittedly Roxbury and Suncrisp were gambles. Still, no on should negate this geneva experience just because it's colder along the banks of the upper St. Lawrence River in central Quebec. These fourteen dead trees shared an underlying cause related to "something" to do with Geneva rootstock.

Lost Nation Orchard
Zone 4b in New Hampshire
Re: geneva curveballs
May 17, 2018 09:13PM
Very interesting topic. Last year I planted three hundred cider varietals on 935 and 202. Had a healthy early growing season until drought and heat came mid-August through September which just shut them all down, even with irrigation. Then a pretty tough winter. Multiple weeks at or below zero. Now I am definitely seeing a lot of dead tissue on branch tips and upper stems though they are leafing out. I think it's more extreme weather than rootstock at this point. Hopefully they can bounce back.

Meantime I just finished putting in 300 two year old trees on B118 and M111 on 7 foot spacing. Slower growing cider varietals on less than ideal soil. Plan to manage them into slender spindle and shoot them skyward. This after a conversation with Eric Shatt and Steve Selin at Stump Sprouts a couple years ago. Makes sense to me. Will be interested to follow these two systems in a side by side situation.
Re: geneva curveballs
May 18, 2018 01:50AM
Michael Phillips Wrote:
-------------------------------------------------------
> As for cultivar hardiness . . . Bramley's Seedling and Calville have been in my orchard going on ten
> years or so; Porter's and Zabergau live as grafts on test branches; admittedly Roxbury and Suncrisp
> were gambles.

What I meant is that these are all "marginally hardy" at best. If you had some of these dead trees with varieties like Duchess, Wealthy, Alexander, Haralson or some other rock hardy varieties, it would be more obvious to put the blame on the rootstock only. My thought is that you had a combination of factors that led to this failure. Probably that the same varieties on a more hardy rootstock would have gone through OK, but possibly also if you didn't have those adverse meteorological conditions on that particular year the trees were planted, they would also have survived and thrived...
Claude

Jolicoeur Orchard
Zone 4 in Quebec
Re: geneva curveballs
May 30, 2018 12:16AM
This was my first year grafting on 935. I used a variety of old southern apples (a handful of Limbertwigs, mostly). I had a really good success rate - I lost maybe a handful out of a 100 that didn't take. Then, over the past week, we had about 8 inches of rain, and it's been damp and humid ever since. The grafts are planted in a nursery bed, and when I checked in on them this morning I'd say more than half of them are dead or dying. The bed drains fairly well, but even so, 8 inches is a lot to handle. I also grafted the same varieties on B118, planted in the same bed, and they're all still doing fine.

Jeff Harner
Takoma Park, MD and Oldtown, MD
Re: geneva curveballs
May 30, 2018 05:04AM
I've also experienced some 2 and 3 year old trees on 935 that have suddenly died also. Not a lot of them, but a few. Will not use it again.

Pat

Brampton Lake Orchards

Zone 4a Upper Michigan
Re: geneva curveballs
June 02, 2018 09:45PM
I have terrible luck with G.11 stocks. 80% of them development an issue around the graft union. The rootstock part dies around the graft. Nothing seems to stop it. I just found a few more trees with dead cambium half way around the graft site. No other trees in my orchard have these issues.
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