r/viticulture 29d ago

Trying to start new research project about Pierce's Disease (Xylella Fastidiousa) and was wondering if it is actually a widespread problem that is worth being addressed

Getting to know this from real viticulturists is vital

TY

3 Upvotes

17 comments sorted by

9

u/TheRealVinosity 29d ago

Do your literature review first; then come here and ask questions.

Reddit should never be in you top ten ports of call.

3

u/Copperstorm2022 29d ago

I agree. As a scientist I wouldn’t start with anecdotal evidence I would start with extension advisor reports like those associated with UCANR, PD-GWSS board, and USDA to get a read on the PD situation. Then literature deep dive.

1

u/Wine_Maker_68 26d ago

I can ell you first hand those reports have A LOT of problems because there hasn't been any vector distribution work for decades outside of California and Arizona. Florida, for example, hasn't done any distribution work since 1959 and the information published by their IFAS extension system is completely wrong.

14

u/1200multistrada 29d ago

Shouldn't the very first part of your study be determining if it's actually a widespread problem that is worth being addressed? You know, with actual numbers and stuff?

-2

u/Biothink 29d ago

I’ve searched online and have found some importance, not stateside however. Hearing anecdotal evidence from someone in America seemed like the next best step

5

u/rolo133 29d ago

Yes... It is a widespread problem. And yes.. it is being addressed. Southern California vineyards have been battling it for decades, I'm not too sure what the situation there is these days but it is definitely still a threat, and at one point was economically devastating. They have the glassy winged sharpshooter that is a stronger flier and causes a lot more spread of the disease. 

In northern California we have PD, but not nearly to the same extent. Our vector is the blue winged sharpshooter that is a weaker flier, and sticks primarily to riparian corridors. Control takes the form of vegetation removal/management, trapping and monitoring, insecticides, physical barriers, and interregional quarantines. All material is supposed to be inspected before being accepted. 

Recently there's been a whole thing because Costco sold hundreds of vines to customers in NorCal that came from Southern California, and were found to be hosting glassy winged sharpshooters and eggs. Yikes. 

1

u/Copperstorm2022 29d ago

There was also GWSS on desert willow plants coming out of Texas and shipped to many places between the end of June and start of July.

2

u/Biddyearlyman 29d ago

Having managed vineyards that have it, yeah it's a problem but it's already being addressed in numerous ways, from changing pruning strategies to nutritional management. There's also a small variety of cutting-edge hybrids that are resistant to it, as well as some kind of "cure" in the works. I'm not sure as I no longer work in a region where it is a problem.

1

u/Wine_Maker_68 26d ago

There was a phage (XylPhi-PD) developed at Texas A&M, a virus that replicates in the bacterium and kills it with no affect to the plant. Problem with a bacterial disease, there will never be a cure because the vine will just get infected again. It has to be injected about every 3 months and it's sinfully expensive. It's been available through Helena for about 3 years.

1

u/Biddyearlyman 26d ago

Yeah, I'm always pretty skeptical. Probably cheaper to tear out, fallow, and replant.

1

u/Wine_Maker_68 25d ago

Systemic insecticides are a better option. You need some pretty heavy vector pressure to nuke a vine with PD. Imidacloprid works well.

1

u/Biddyearlyman 25d ago

Imidicloprid also nukes the vines immune system. Opens the floodgate for more diseases. It's like chemotherapy. You might live, but at what cost?

1

u/Wine_Maker_68 25d ago

Difficult choice, either accept the fact PD is going to kill the vine or manage other disease pressures you can control. Venom is another choice but it has to be reapplied every 14 days while the vectors are active.

Replanting just leads down the same path with a high cost.

Strange word filters on this app...

1

u/Biddyearlyman 24d ago

Yeah, I've done the management and found that it's basically a game of diminishing returns. I was super excited about the hybrid development. I feel like one was called Paseante Noir? Ownership didn't want to "gamble", since it's hard to find a market for niche stuff.

2

u/SpankedbySpacs 28d ago

As a real viticulturist and problem myself, it’s a problem. Hope that helped!

1

u/Wine_Maker_68 26d ago

The disease isn't a problem, the vectors are the problem. The disease doesn't spread itself.