Two-spotted mite help?

[tsmack]

Hey HopUnion, I've got 200 rhizomes of Cascade in the ground in Virginia, and they're growing away pretty well, but our local extension agent just diagnosed them with a two-spotted mite infestation. He's looking into what we can use to help get rid of them, but he's fairly unfamiliar with hops. Do you guys get these? What can we use to remedy this problem?

Thanks a million,
-Taylor

[REV]

If you didn't want to mess with chemical applications you could look into introducing a biological control agent. Phytoseiulus Persimilis is a predatory mite that has proven effective at controling two spotted mite infestations. They have been used on hops before.

Good luck,

The REV

[BelgianBrewer]

A friend of mine treated them once with a soapy solution.
Mix water and some dishwashing detergent into a hand sprayer.

I have never tried it myself so I can't guarantee anything, but given the cost and the effort it could be worth a try.

Let me know hpw it goes.

BelgianBrewer
www.sbmbrew.com

[SteveO]

A 10% soap solution is what you want. You could also use a product from Safer, the company produces very earth and people friendly products. SaferSoap is the one to try. Good Luck, Steve O

[tsmack]

Thank all you guys for the input. That's interesting about the soap solution. We may go that route next year when we're trying to be a bit more organic. For now, we fired up the serious stuff...our extension agent came back with something that is recommended especially for hops and is also used on apple trees. It's called Prev-AM and is based on some kind of extract of orange peels, but there's a lot of other napalmish stuff in it. It's supposed to fight mites and mildew (which we're not suffering from, thankfully).

But thanks again for the input!

-Taylor

[Gael]

Spider mite is best controlled early in the year - around May, before the mites have even started "webbing" the foliage. After the vines have been pruned, excess cut away and disposed of, and strung, spray the vines with a 2% pyrethrum spray. Pyrethrum (a distillate of a particular kind of marigold - French Marigold) is a natural substance and can be found in organic formulations with soaps as a spreader and wetting agent. It's pretty easy to apply with a backpack sprayer. It's a good idea to spray the poles too, as mites may be lurking on them too.

Later in the season, at the burr stage, it's better to use lime sulphur, in a 1% solution. Again, commonly available, but be sure not to get the fruit tree sprays with dormant oil. Lime sulphur will not hurt the plant, and may need to be repeated in a week or so from the first spraying.

One additional note: if you have been using sprays which are also designed for mildew control, you have likely been propagating spider mites, because these mixes tend to kill the natural predators of the mite.

I understand that the major predator of spider mites is the Anthrocorid Bug, which I have never actually sourced or identified in my hops.

If you possibly can, increase the prevention tactics next year: clean up around the vines (will help with all kinds of diseases), add lots of compost (your soil and plants need all the micronutrients), and drip irrigate plentifully. It's an amazing thing, but healthy plants will withstand both diseases and pests. Oh, and plant other crops around your hops to encourage beneficial insects!

[brewkettle]

We also have about 250 vines in the ground. We have Nugget, Cascade, Liberty and Willamette, they went in in April 2006. The rows are approx 100' long with 39" between plants and 14' between rows. Last year we let them sprawl out. This year we have them up on 8' wooden tomato stakes which are extremely over burdened.
I know its a little late for planning now, but we need to get a trellis system in place that would seem appropriate for a plot as small as ours. Does anyone out there have, or has anyone seen anything that might work other than the full blown 18' poles?

Chris McKim
The BREW Kettle Taproom and Smokehouse
Strongsville, Ohio 44136
440-239-8788

[Gael]

There's a reason for the 18' poles, actually. Hops tend to produce higher up on the plant - above 3'. So if you want to get a decent crop, you need some height for them to work on, unless you've managed to lay your hands on dwarf hops, in which case I want some too. We use 20' poles, 3-4' in the ground, for a 16' trellis, which is a tiny bit easier to manage than the 18', if you don't have specialized equipment.

That said, you'll need poles no less than 30' apart, with decent cable - 1/4" aircraft is good - running both ways between them. Use cable for cross-wires as well, anything else will stretch under the weight of the hops. If your vines are less than 5' apart, put your poles closer together and for heaven's sake guy line them well.

For more info, check out our website, which has a small-scale hops manual on it. You can download the PDF and print it yourself, or pay me a tiny bit to mail you a hard copy. There's info there on trellising. Or email me for more.

www.crannogales.com