Treatment with Spraying Oils

[Maggi Young]

I have collated the posts from one of the Crocus threads to make this new topic.......

{quote author=Armin } I found out rape oil as a very good and harmless method to minimize aphid infestation i.e. on my rose bushes.

Armin....please tell us, how do you use the rape oil ?

{quote author=Armin }
I mix 100 ml rape oil (from discounter, < 1,-Euro/ltr) with ~6 Ltr water. In order to get an emulsion I add a few drops of liquid soap concentrate (<1,-Euro a bottle from discounter) and shake it well. Then I immediately spray my roses from all sides.
Causion: do not spray when it gets/is hot and sunshine as the oilfilm can burn the leaves!
The best is to my opinion to spray in the late afternoon.

Above mixture helped 100% against heavy mites infestation on my roses (sprayed every week, 3x times ttl) and also against aphids. The emulsion (oil) encapsules the parasites and they die. It also suppress the growth of downey mildew (in an early stage of infestation) on young shoots.

The challenge is to keep the oil in an emulsion for good surface distribution and I still try to optimize the recipe. If you add to much soap it harms the leaves...
Therefore I'm thinking of to use i.e. lecithin (=natural tensid, (in egg yolk)) (from drug store or pharmacia) instead of the soap next season...
I will make a trial next season to use it proactively biweekly.

In case of crocus I can imagine a good result in case they are in leaf status. I would not spray when they are in blossom.

Dutch commercial nurseries usually use a combination of mineral oil and systematic insecticides (based on synthetic pyrethroids) because, eventhough the aphids might die after sucking up the sap with the insecticide, possible viruses might already have been transmitted, the mineral oil makes the plant less attractive to aphids so it prevents them from even start sucking.

A virus takes only 24 hours to spread in the entire body of an aphid and once on the mouth parts there is no stopping the virus if the aphid makes a hole in the plant and comes into contact with the plantsap.

A combination of the 2 therefore is the most effective method. It depends on how precious the plants are because it is quite labor intensive. Although most systematic insecticides only need to be applied a couple of times during the season, mineral oil needs more frequent application. It also depends on the insectide, the emulsion concentrates get in the wax layer of the plant and are less likely to be washed away, the ones applied through waterings generally only need 2-3 applications during the season.

One of the latest insecticides is Sumicidin, an insectide that also has a small repellent effect but I am not sure if it is available for gardeners in the various countries.

The sprays from the garden centres based on fatty accids as an alternative to mineral oil also work quite well, they just smell of an old sock...

Pascal,
thank you for the details of virus growths/spreading and commercial growers treatment. No objections from my side.

As a matter of fact it is impossible to grow modern rose hybrids without proactive treatment with fungicides and systematic insecticides.
B of June with the first very hot summer days I realized the start of infestation with mites. I immediately sprayed 3 times a systemic insecticide without any success!
The mites got resistent against the agent Dimethoat I used over the last 15 years I grow roses... (I didn't notice that the substance is since this year no longer recommended against mites, too. )
 
After leaves got already brownish with visible mite web, the use of rape oil was the genius thought to end the tragedy.
The successful treatment of mites needs to be repeated 2-3times to kill all the new hatched mites from surviving eggs...
Last time I applied it again in September when I noticed aphids and downey mildew.
The advantage of rape oil over mineral oil it is ecologially harmless and cheap.
It works excellent!

Hi, I got to this post rather late but am very interested in your use of rape oil. I wonder if it has the same properties as Neem oil or other spraying oils which I use on my pleiones during the dormant period to combat the Brevipalpus mite. Neem oil is very expensive and hard to get. where do you get rape oil? is it the same as culinary rape seed oil?

Hello Maren,

it is culinary rape seed oil from the discounter I use. It kills Panonychus ulmi and Tetranychus urticae outside in the garden.

I have no idea if it has an effect against Brevipalpus mites and Pleiones leaves tolerate rape oil.

Rape oil is not harmfull and has no systemic effect. The film of oil encapsules the mites. They get glued, can't move, breath and finally die.
Important is to spray the undersides of leaves with highest infestation.

Have you tried to spray / water preventive with a cold water maceration of onion- and garlic skins? (available in every household)
The active substance Allicin frighten away the saugers.

Maren - I am curious to know if you have had success with Neem.  When it first came out I was given samples and gave some to Glendoick Gardens for testing.  They reported back that it was not really useful for their purposes in such a cool climate.  I understand in warm & hot climates it has been very effective outdoors.

johnw

Hello John,

it's hard to say whether Neem oil is successful or not for my purpose, I guess it must be because I have never had any Brevipalpus mite in my collection. According to Ian Butterfield, it is easy to spot because it turns pleione pseudobulbs to mush.

I feel a bit guilty about elaborating on this topic, maybe we could have a separate one for Treatment with Spraying Oils or something like that. then I can explain what I do, which is quite different to what others have described here.

[Maren]

Thank you Maggi, making a new thread is very helpful.

Now this is what I do with my spraying oil, which I bought from a hydroponics supplier. I mix it with the required amount of water according to the instructions on the bottle. Then I shake it up vigorously to make an emulsion. This is sprayed on the dried pleione pseudo-bulbs, that means, about a week after they have been harvested and laid on newspaper in the store, frost-free, with the de-humidifier going at max.

The bulbs are in trays, so I spray them, then turn them and spray again until they are covered completely. Another method is to pour the liquid over them in a sieve, then strain the liquid before re-use. Ian thinks this is not a good method because once the liquid has picked up a pathogen, it will go everywhere. Makes sense, I think.

Regarding the smell of old socks, yes, but it doesn't last.

A tip if your spraying oil has solidified in the bottle, which can happen if it is stored in a cold place. Just unscrew the top and stand the bottle in the microwave for half a minute. Best stand it in a plastic bowl, in case it falls over. Otherwise it's old socks in the kitchen for a week!!!

The business with Neem oil is that DEFRA has not given approval for it to be used as an insecticide. I had a correspondence with them that went like this (shortened version):

Maren:   I grow orchids. Can I use Neem oil on them as an insecticide?
DEFRA:   No, you cannot use Neem oil in orchards.
Maren:   Actually I said orchids, not orchards, I know, an easy mistake to make.
DEFRA:   Sorry, but you still can't use it as an insecticide. It's not licensed.
Maren:   Can I use it as a leafshine, that's just cosmetic?
DEFRA:   Yes, that's alright.

I guess DEFRA rules like this because nobody has applied for a certificate and paid the substantial fee. However, Neem oil has been approved as a cosmetic; there is more money to be made with cosmetics, so the companies marketing it can bear the cost of licensing.

I therefore use the oil for the sole purpose of making the bulbs nice and shiny, not to deter bugs.

[bulborum]

This is the same story as for clove powder
and garlic powder in Holland
they are weakening insects
so you have to use less insecticides
but nobody will ask a license for that
to expensive
forbidden to use as insecticide
but I use it as perfume   

Roland

[Darren]

Just thought I'd mention that I have used 'Vitax 2in1' which is a mixture of oils and (I find) is very effective against red spider, and is licensed as a pesticide. I have also been dipping my pleione pseudobulbs in a spray-strength solution of this. As I have had no new pleione since clearing my collection of Brevipalpus several years ago (using Neem oil ) , it is hard to say how well this works but I assumed that the mechanism by which it kills red spider would also apply to brevipalpus. The vitax product is great for preventing red spider damage to succulents also but it does spoil the look of anything with a glaucous bloom on the leaves such as many mesembs and agave.

[Armin]

This is the same story as for clove powder and garlic powder in Holland they are weakening insects so you have to use less insecticides
but nobody will ask a license for that to expensive forbidden to use as insecticide but I use it as perfume   
Roland

Roland,
I'm interested in your perfume mixtures. Can you please tell more details?

[bulborum]

Both weaken aphids and mites
I buy it by the kilo in the wholesale   (Macro)
ad a cup in 5 litre water and spray the plants
next day I spray with a commercial product
because they are weakened you need only a light solution
to kill them

Roland

[Lesley Cox]

forbidden to use as insecticide
but I use it as perfume   

Roland

Chanel No. 13?

[Maggi Young]

http://www.srgc.org.uk/smf/index.php?topic=6326.msg175147#msg175147

'monocotman' wrote there :
"hi there,

I'm looking for some advice on the use of neem oil for brevipalpus on pleiones. I'm not sure that I have an infection of them in my collection but it may be good to treat the bulbs occasionally whilst dormant anyway.
Can anyone describe the symptoms?
I've bought a small bottle of the oil from ebay and have been recommended to make up a 1% solution of this with water and to add some soap as a sufactant.
Is this correct? When is the best time during dormancy to spray? Can it be done anytime? Can I use ordinary soap?

Many thanks,

David"

I'd prefer to keep the Neem  discussion here, please.

[PeterT]

This is the same story as for clove powder
and garlic powder in Holland
they are weakening insects
so you have to use less insecticides
but nobody will ask a license for that
to expensive
forbidden to use as insecticide
but I use it as perfume   

Roland

Do you wear the cloves and spray the garlic, Roland?
 or wear the garlic and spray the cloves?

[PeterT]

I believe some Pleione growers dip the dormant pseudobulbs in methylated spirits (alcohol), with no adverse effect on the plant. = all pests DEAD 

[bulborum]

How do you wear what Peter

Roland

[PeterT]

I don't wear the Garlic Roland,
untill now I only grow and eat it.
Soon I will spray it to perfume my Iris
and chase the insects away.

I wear the Cloves on my clothes,- to chase the moths,
and I eat them in apple pie.
When my Iris smell foul of Garlic cloves,
perhaps I shall sweeten them too,
-with another kind of Clove.

In years gone by,
sweet gardens of Roses were planted,
and each sweet bed had an Onion edge.
The roses must have still smelt sweet
safe behind the garlic-
and safe from the aphids!

[bulborum]

          



Roland

[PeterT]

Thank you Roland 

[mickeymuc]

Hi Everyone,

I thought I'd mention that in Germany there is a ready-to-use concentrate in the trade, which just has to be diluted with water. I've made the best experience with this, and it is very cheap when you take into account how much spraying solution you can make from it. Also I think it is more safe than any home-made neem dilutions. The name is "Celaflor naturen Schädlingsfrei neem", and it is available in the trade here, maybe also in the German ebay and in online stores.
I can recommend it both for treating Pleione pseudobulbs as well as many other plants against spider mites and aphids - so if anyone wants to try and has problems in purchasing it pm me and I'll do my best to help.

Michael