Gem infected with pear vein yellows, a common pear virus

Grafters always run a risk of viruses. Change your blades with this variety. Do you still want to grow it? The important thing to remember with pear viruses is they impact different trees in different ways. Viruses like stony pit can be devastating to orchards. This seems like a great pear but we need to take extra precautions with this variety before bringing it into our orchard.
New pear is twice as nice - Good Fruit Grower

" New pear is twice as nice

Oregon growers harvest nation’s first commercial crop of Gem pear, a variety that eats well right off the tree and after storage.

November 2019 Issue

Ross Courtney, TJ Mullinax // November 26, 2019

Grower Dwight Moe holds up a Gem pear, picked in mid-September at his Hood River, Oregon, orchard. Moe and other orchardists with the Diamond Fruit Growers cooperative harvested the nation’s first commercial crop of Gem, a pear that can be eaten crispy right off the tree or ripened to a soft texture in storage.(TJ Mullinax/Good Fruit Grower)

From a bin near Hood River, Oregon, Dwight Moe selects a pear, slices it and passes out samples. It’s juicy, crispy, sweet and most importantly, picked just minutes ago.

It’s called Gem, and Moe and his fellow orchardists at Diamond Fruit Growers hope its eat-ability right off the tree convinces shoppers to give pears a chance.

“That’s one of the beauties of that variety,” said Moe, one of a dozen or so growers who brought in the nation’s first commercial harvest of the blush variety, which was developed at the U.S. Department of Agriculture’s Kearneysville, West Virginia, breeding program to meet consumer preferences for fruit they can eat right away.

Actually, Gem poses a dual threat in the market. Yes, the pear is good right off the tree, but with storage it will soften into the creaminess that many consumers expect from a pear. The industry dubs it “buttery-juicy melting texture.” Meanwhile, it resists browning after being sliced.

Moe, left, and Steve Moore, the field service representative for Diamond Fruit Growers, discuss the 2019 Gem harvest.(TJ Mullinax/Good Fruit Grower)

In September, Diamond Fruit had expected about 100 bins this year of Gem, said David Garcia, general manager of the cooperative. The catch may have been even larger if not for a hailstorm that month, which affected some of the later orchards.

The Hood River-based cooperative picked between 30 and 60 bins the past two years, enough to conduct some chilling trials. This year is the first they are trying to market the fruit.

Steve Moore, a field representative for Diamond Fruit, said the pear keeps well in cold storage for four to five months. In controlled-atmosphere trials with ethoxyquin treatments, it stored well until summer.

New pear varieties in the Pacific Northwest, where most of the country’s pears are grown, have been hard to come by. Some of the latest and greatest are club varieties out of New Zealand, while traditional Anjous and Bartletts have fallen on tough market conditions.

Gem, an open access variety, is a cross between Sheldon and a numbered variety with Comice, Bartlett and Seckel in its family tree.

The precocious cultivar is touted for lack of russeting, tolerance to fire blight and nonbrowning flesh, according to Todd Einhorn, a horticulture professor at Michigan State University. Bloom time coincides with Bartlett, and it’s compatible with Bosc, Anjou, Bartlett, Comice and Starkrimson. It shows some degree of self-fertility, Einhorn said, and produces a lot of fruit, which usually requires thinning, especially if growers want large pears.

Todd Einhorn speaks about the Gem pear at the Oregon State University centennial celebration at the Mid-Columbia Agricultural Research and Extension Center in Hood River in August 2013. Now a horticulture professor at Michigan State University, Einhorn formerly worked for OSU and introduced Gem pears to the Northwest through his trials.(TJ Mullinax/Good Fruit Grower)

Einhorn formerly worked for Oregon State University and introduced Gem pears to the Northwest through his trials.

The variety is infected with pear vein yellows, a common pear virus, Einhorn said. Nurseries and growers can avoid spreading the virus by not grafting or budding. The virus is not transmitted by pollen and does not seem to be transmitted by insects, he said.

For pears, Gem trees are not too vigorous, possibly due to the virus, so two-leader or central leader training works well, Einhorn said. He recommends trellises so growers can establish blocks in high densities, emphasizing the need for narrow canopies. Sunlight exposure is critical to develop its red blush. Old Home by Farmingdale 87 is the suggested rootstock, depending on site.

“Good growers can make just about anything work,” he said.

Harvest timing

Finding the right harvest time may be a tricky balance. It was expected to pick near Anjou timing, but Diamond Fruit field reps recommended letting it hang a little longer for softer, larger and sweeter fruit.

Moe, a fourth-generation grower, harvested before the storm but later than he expected, on Sept. 11, 10 days later than his Anjous. Moore had urged him to let his pressure — an indication of maturity — drop to between 10.5 pounds and 11 pounds per square inch before picking, higher than the 10 to 10.5 range recommended as a maximum by Einhorn.

“I’ve been eating them for two weeks and it’s like, ‘When are they going to be ready?’ And they’re just wonderful,” Moe said on harvest day.

He opted for free-standing central-leader trees on OHxF 87 rootstocks planted at 10-foot spacing with 15-foot rows. In hindsight, he wishes he would have chosen 7-foot spacing with rows between 12 feet and 14 feet.

Gems hang heavy on a branch awaiting harvest in Moe’s orchard.(TJ Mullinax/Good Fruit Grower)

One thing he noticed is the branches seemed brittle, so he has his crews pushing crotch angles wide early in the season, to avoid snaps. He doesn’t dispute that the cultivar has some fire blight resistance, but he did lose a few Gems this year to blight. He also has heard of neighboring growers experimenting with summer pruning, but he hasn’t heard the results yet.

“We’re learning,” he said.

His family has a history of trying new varieties since his grandfather started the farm in 1905. Taylor’s Gold, Concorde, Seckel and several Asian pears were among the attempts.

“They just never made a hit,” he said. “I’m just hoping this Gem makes a hit.”

Scott Halliday, a Diamond Fruit grower located in a late section of the Hood River Valley, didn’t harvest this year because of hail, suspecting the lower pressure sought by the company left the pears more vulnerable.

Einhorn cautioned against a rigid conclusion, though. Hail can damage fruit any time during the season over a wide range of flesh firmness.

Jose Lopez Lomeli picks Gem pears in one of Moe’s free-standing orchards, this one planted with 10-foot by 15-foot spacing.(TJ Mullinax/Good Fruit Grower)

Halliday decided to trellis most of his 7-acre Gem block, training the trees to in-row dual leaders to slow down the variety’s apical dominance and make way for platform use someday. He left some free-standing central leaders as a comparison. He went with 8-foot tree spacing and 15-foot rows because of his available land, but if he plants more he will switch to 14 feet. For rootstocks, he used OHxF 97.

“Right now they grow well,” he said. “They put on a lot of fruit, so they need a lot of thinning.”

He was attracted to the double-edged marketing sword of Gem. He knows some shoppers prefer pears they can “eat with a spoon,” but younger shoppers are turned off by having to wait for pears to ripen.

“We just think there are too many consumers out there who don’t eat pears at all … we have to give them something that’s ready to eat,” Halliday said. •

—by Ross Courtney

The quest for new varieties, cold-hardy rootstock
Overcoming the pear plateau: Interpera 2017 (includes video)
Pear industry ripe for a rescue

November 26th, 2019|Marketing, New Developments, November 2019 Issue, Pears, Production, Ross Courtney, TJ Mullinax, Trade, Varieties

About the Author: Ross Courtney

Avatar photo

Ross Courtney is an associate editor for Good Fruit Grower, writing articles and taking photos for the print magazine and website. He has a degree from Pacific Lutheran University. – Follow the author – Contact: 509-930-8798 or email."

Then now do they propagate the variety?

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The propagated tree has the virus. There is good news about it also.

" Pyrus communis ‘Gem’

This disease-resistant beauty is a real jewel! Gem has proven itself in extensive testing around the nation and is newly released by the USDA and bred by Dr. Richard Bell. The large, beautifully red-blushed fruit is juicy and sweet, with a delicious mild pear flavor. It ripens mid season and is a good keeper. It can be eaten mature from the tree while it is crisp and sweet or be stored and allowed to soften and ripen fully.

It is highly fire blight AND cedar trellis rust resistant and is very productive at an early age. Bloom category 1.

USDA Zone: 4-9

Grow Height: 15’ (Semi Dwarf)

Sun: Full Sun

Ripening Time: September

Pollination: Needs a Pollinizer"

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It’s grafted onto rootstock like OHxF87 as mentioned, so I assume beyond its own graft perhaps they are not recommending adding it to other trees as a multi-graft.

Hmmmm. I purchased Gem scion to include on a multi-grafted espalier… So perhaps I need to dedicate it to one tree.


So I’ve read a few things on this yellows vein virus…

I don’t see anywhere that it kills the tree, but only stunts growth. No mention of any fruit effects.

I did find one bmurb that says heat treatment before grafting might help.

"Cultural control

Use scions and rootstocks that have been tested and found free of all known viruses.

Heat treat infected tissue at 37°C and then propagate by meristems or shoot tips."


@Shibumi @marknmt

If gem is infected as they say it is i dont feel that is a deal breaker but rather just something we needed to know. Like i mentioned change blades before further grafting @Shibumi and wash up good. A virus on one tree is not a big deal as long as you know it.


See this thread where i point out a novelty pear several people wanted to try looked a lot like stony virus (Ginnybrook pear) . It turns out what was sent out and planted did not look like the picture. It was likely stink bugs that gave it the appearance of stony pit virus. They frequently do that with asian pears here on my farm.

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I’m sure I’ll change my mind a dozen times or so before my scion arrives, but for now on the non-asian pear side I have these coming.


Hood (an actual tree).

I have two nice caliper OHxF87 ready and in place to start espaliers. Two more smaller caliper OHxF87.

I’ll have to see on the caliper of scion as to what I can do with the smaller ones.

I’d like to graft all 4 scion I bought and perhaps try saving a part of each to see if I can summer graft the second cordon depending on the graft growth.

I’ll be able to report on how Gem does in the coming years, as well as if the purported chill hour estimates workout for me here.

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Couldn’t they eliminate the virus in cell culture?



I would have thought so myself. Went ahead and ordered a tree anyway. That tree will be isolated from my other trees.

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It’s an interesting writeup that outright says it isn’t transmitted by insects.

That seems contrary to evolution. What virus hasn’t found a way to reproduce by jumping to another host?


Some big rose growers- wholesalers did the same. Breed a new rose, then knowingly bud it onto rose-mosaic infected rootstock and release it. :confounded:


Good luck:)

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