Greenfly / White Fly

[jmc]

Greenfly & white fly have infested one of my new (progress) hops, really stunting the leaves.
They are also beginning to appear on some other hop plants.

I've given them one go with a chemical insecticide, but it was horrible stuff which I don't want to use again if possible, especially as I have herbs growing underneath, so I'm after a more natural alternative that I can use from now on.

I've read that some spray a dilute washing up liquid, but I tried that last year on one hop, to no great success.

I was reading an old (1919) book on English hops from the William Nurseries site and they mention this (page 41)

Washing
All practical and scientific hop growers rely much upon washing to free hop-bine from insect pests.
A mixture of soft-soap, sulphur, quassia and water is sprayed on the growing hop-plants by means of a hand-pump or a machine-pump, drawn by horse or motor power. Tobacco infusion is also used. Enterprising growers wash as soon as the aphids appear in their plantations.

Sulphuring
The use of flowers of sulphur has long been known as an excellent antidote to the mildew, over the whole plant before the burr develops into a hop.

I looked into Quassia and its a very bitter wood (50 times more bitter than quinine)
Looks like you can make it into an insecticide
From wikipedia

Insecticide
Extracts of Quassia wood or bark act as a natural insecticide. For organic farming this is of particular interest. A good protection was shown against different insect pests (eg. aphids, Colorado potato beetle, Anthonomus pomorum, Rhagoletis cerasi, Caterpillars of Tortricidae).
Quassin extract works as a contact insecticide. Adverse effects on beneficial organism were not found.
...

Formulation
Around 200 grams of Quassia wood chips are put together with 2 litres of water. It is allowed to stand for 24 hours and then it is cooked for 30 min. It is then diluted with 10 to 20 liters of water and used as a spray. The use of approximately 3-4.5 kg wood extract per hectare seems to be optimal to minimize the damage of Hoplocampa testudinea on apple trees.[5]

I've ordered 100g of Quassia chips and will give it a go.

Has anyone else tried this?

[seymour]

...Has anyone else tried this?

No, but I'm absolutely intrigued. Best of luck, and I can't wait to hear more.

[themadhippy]

washing up liquid and garlic works for me,also try and get ladybirds to move in

[seymour]

washing up liquid and garlic works for me,also try and get ladybirds to move in

Similarly, I've heard of organic hops growers who also raise chickens will occasionally give them a supervised "walk" around the hopyard. The chickens flutter around gobbling-up the pests, which benefits the hops plants and apparently leads to improved eggs too.

[jmc]

washing up liquid and garlic works for me,also try and get ladybirds to move in

Cheers.
I had loads more ladybird larvae last year. The cold snap we had seems to have reduced number of ladybirds this year.

Hadn't heard of using garlic before.
I'll probably add it to the mix.

I did a quick search and others use it too

Since I don’t have available a black and red thank (little ladybugs are the best against aphids) I will have to go with garlic artillery. Here is a recipe for making organic garlic garden spray.

Aphid
Aphids are one of the big enemies on the garden

Aphids usually dislike plants with strong and powerful scents like those in the allium family (onions, leeks, chives, garlic, etc.). All the plants in the onion genus have very astringent chemical compound, which gives them their "spicy" or "garlicky" flavor, this serves as a natural repellent for many pests and some fungus. Using a spray of this chemical around the garden will help in getting aphids away in a very natural and organic way.

The recipe is very simple, and after using it a couple times, the results will be visible.

Ingredients
* 2 cups of water
* 2 cloves of garlic
* 2 tbsp. liquid dish soap

Optional
* 1 small onion
* 1 tbsp. Mineral oil

[scuppeteer]

Bit late now, but for next year, apparently French Marigolds are great for aphids etc. They are attracted to the flowers more than hops and generally leave the hops alone. And of course ladybugs are the best deterrent. Although have yet to see any, anywhere near my hops this year.

[jmc]

Friday evening I tried a new spray mix using the quassia wood, garlic and liquid soap.
Not sure which of the ingredients they dont like, but it seems to have done the trick for now.

I based amounts on advice from Wikipedia mentioned in previous post

Formulation
Around 200 grams of Quassia wood chips are put together with 2 litres of water. It is allowed to stand for 24 hours and then it is cooked for 30 min. It is then diluted with 10 to 20 liters of water and used as a spray. The use of approximately 3-4.5 kg wood extract per hectare seems to be optimal to minimize the damage of Hoplocampa testudinea on apple trees.

According to this, 200g would make 10-20L of diluted spray, so to make life easy I worked on 200g per 16L diluted spray = 25g per 2L diluted spray

I soaked 25g of quassia wood in 1L water for 24 hours then simmered this mix for 30mins
Then diluted to 2L and filtered to remove tiny bits that would clog up sprayer.

I also incorporated other stuff aphids dislike based on previously mentioned recipe

* 2 cups of water (=1 US pint)
* 2 cloves of garlic
* 2 tbsp. liquid dish soap

so to factor up garlic / soap from 1 US pint = 0.568L to 2L I needed to add
7 cloves of garlic! (I added these chopped up to last 5 mins of simmer)
& 7 tbsp of liquid soap

[Beer O'Clock]

Bit late now, but for next year, apparently French Marigolds are great for aphids etc. (

That'll be because even they hate the French

[Blackaddler]

I've read that some spray a dilute washing up liquid, but I tried that last year on one hop, to no great success.

That's been my weapon of choice on aphids for years. You do need several applications overs a number of days, and sometimes need to up the concentration of washing up liquid. It certainly works on blackfly and greenfly. I'm not sure about whitefly, as It's not something I see very often.

Make sure that you spray both sides of the leaves.

After the wind burn a couple of months back, both my wild plants stopped growing for about 4-5 weeks, and all the lower leaves turned brown. They only just started to recover when the whitefly took hold. They're both a sorry sight now.

[jmc]

...Has anyone else tried this?

No, but I'm absolutely intrigued. Best of luck, and I can't wait to hear more.

Hi Seymour
I found another couple of references on Google Books to the use of quassia to reduce aphids
see
here
and
here

They mention quassia's not as effective as nicotine-based sprays, but I'm happy if they're non-toxic and minimise the amount of aphids.

I may make up a new batch without soap to use during the hot spell we're having as I read that you shouldn't apply sprays with soap or oil if plant is drout-stressed
from http://www.dummies.com/how-to/content/u ... sects.html

Soaps and oils kill a wide range of pest insects, but affect beneficial insects, too. Insects breathe through pores in the cuticle that surrounds their bodies. If you plug up the pores, the insects suffocate and die. Disrupt the cuticle with special soaps and oils and — poof! — the insects can’t maintain their internal moisture.

Oils do have several drawbacks. Don’t use them when temperatures are likely to rise above 90°F, when plants are suffering from drought stress, or if you have applied or plan to apply sulfur fungicide within 30 days.

I suppose the soap fills up the pours in the leaves too, reducing transpiration further?

** edit typo

[Cully]

We grow lots and lots of tomatoes every year, and the wife plants marigolds round the base of each one and it really does work! Nature, eh?

[jmc]

Update...

A few days after applying quassia / soap garlic spray plants were all near-enough insect-free.

Unfortunately the new Progress plant with the worst infestation looked really stressed.
I think adding spray including soap on a poor plant when its really hot wasn't a good idea.

I hosed plants down that I'd sprayed and I've tried to water more than normal.

Plants look much happier now. The odd greenfly back but lots of new shoots and healthy new leaves.
Also got a few ladybird larvae now munching away as well

Next time I'd skip soap in mixture if we're having a heatwave.

[orlando]

Update...


I hosed plants down that I'd sprayed and I've tried to water more than normal.

Plants look much happier now. The odd greenfly back but lots of new shoots and healthy new leaves.
Also got a few ladybird larvae now munching away as well

Watching Gardeners World the other week (so rock & roll these days) Monty was advocating just that, no soap just a vigorous spray to knock the things off. Once on the ground they don't go back and presumably are predated by gardener's friends.

[barneey]

I thought my hops were looking a little under the weather check them today and have quite a few green fly things on them (yellow leaves as well) so have treated them.

On one of the plants I`ve found a few rather large cricket sized things, are these good or is a size 12 needed?