Control of Aphids on hop plants?

[Ralph]

Hey all, 

 

My first attempt at growing some hops at home. The bines are coming up through the ground and starting to wind their way up the twine which is all good. I have noticed that the plant is covered in aphids tho.

 

Anyone know what the best way to deal with these little critters on a hop plant is?

[Chris Mills]

Gently spraying with water to knock aphids off is a good place to start. From there you can make some basic sprays with garlic, mineral oil and dish soap. If you have ants you may find that the little critters are farming the aphids and carrying their little green livestock onto your plants so you may also have to address an ant problem on top of your aphid issues.

 

http://organicgardening.about.com/od/pestcontrol/a/spraysforaphids.htm

Garlic Oil Spray

Organic gardeners have long relied on garlic as part of their pest-fighting arsenal. Garlic contains sulfur, which, besides being toxic to pests, is also an antibacterial and antifungal agent. The dish soap in this mixture also breaks down the bodies of soft-bodied pests, such as aphids.

What You'll Need:

• Three to four cloves of garlic
• Mineral oil
• Strainer or cheesecloth
• Liquid dish soap
• Water
• Spray bottle

To make garlic oil spray, mince or finely chop three to four cloves of garlic, and add them to two teaspoons of mineral oil. Let this mixture sit for 24 hours. Strain out the garlic pieces, and add the remaining liquid to one pint of water. Add one teaspoon of liquid dish soap. This mixture can be stored and diluted as needed. When you need to spray, use two tablespoons of the mixture added to one pint of water in a spray bottle.

To use your garlic oil spray, first test by spraying an inconspicuous part of the plant to see if your mixture harms it at all. If there are no signs of yellowing or other leaf damage after a day or two, it is safe to use. If there is leaf damage, dilute the mixture with more water and try the test again. Once you have determined that it won't harm your plant, spray the entire plant, paying special attention to the undersides of leaves.

Warning: Garlic oil is a non-selective insecticide, which means that it will kill beneficial insects (such as lady bugs, who are natural predators of aphids) just as easily as it kills the bad guys. It's best to keep as many beneficials around as possible. This spray should only be used if you haven't seen any beneficial bugs in your garden. The tomato leaf recipe, above, won't harm beneficials, so you should use that if you're lucky enough to have some beneficials in your garden.

These sprays [edit - there was another tomato leaf spray on the same page] are easy to use, inexpensive, and effective. As you can see, even organic home remedies require care and attention to their effects. In general, use each spray as little as possible, and use it responsibly. You'll win the battle against aphids, and still have a healthy garden after they're gone.

[Ralph]

Would it have to be mineral oil, or do you think something like 95% ethanol would suffice to get the good stuff out of the garlic? I am not even sure what specifically mineral oil is or where to get it? I am guessing they have it in hardware stores next to the meths and turps?

[Chris Mills]

Mineral oil is there to make it sticky. You might also find it at the pharmacy. I'd go with C. Bank's suggestions below.

[Ralph]

I would have thought the liquid soap would make it sticky rather than mineral oil and I would have thought the mineral oil was there to extract the active agents out of the garlic, which is why you sit the crushed garlic with the mineral oil for 24 hours.

 

The Chris B soapy water idea seems easier tho! I will try it.

[Dougal]

Mineral oil is used as a sticker in sprays so the droplets coat the surface better, and detergent is used to dissolve the waxy coating on the skins of aphids, causing them to dessicate and die. Both work well on their own- I've never used them together but it may work well.

It's probably worth adding that subjecting plants to water stress is the best way to get an aphid infestation. I made sure my hops were well irrigated from the time flowers formed last season, and (in addition to a bumper crop) there wasn't an aphid to be seen. 

[Ralph]

It has been well watered and I doubt it is water stressed. There do seem to be large numbers of aphids in our area that quickly infest plants tho.

[Andrew]

If you want to do it the natural way you could companion plant, which is use one plant which repels pests beside one that would normally attract them:I thinkthis is what most of the hop farms do here to stop using pesticides but I can't remeber what they grow beside the vines.

http://en.wikipedia.org/wiki/List_of_companion_plants

http://www.simpleearthhops.com/p/companion-planting.html

You can buy already growing plants  from Mitre 10 etc but if you grow from seed it will take a while to work by which time your hops will be toast. You can spray but then I,m never keen on spraying chemicls on something I'll be comsuming large quantities of.

[Chris Banks]

For me soapy water normally does the trick - 5mls of plain handsoap to a litre of water.

As long as the infestation isnt to bad it normally works after a couple of applications 4-5 days apart.

If it does get bad my next choice would be a pyretherum based spray from the garden centre.

The insecticide Confidor is very effective also but as others have pointed out a last resort.

[Pilgrim]

Neem Tree Oil. It controlled the Passion Vine Hoppers on mine and it's a natural substance, mind you so is Rattlesnake venom :-)

[donald stewart]

when i was on the farm i use to spray the lucerne with globe fishery fish fertiliser

it would give the plants a feed and get rid of the aphids

lock up your dog , they love to role in it and come and tell you how good they smell