Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: CliffordK on 13/02/2013 04:18:28

Title: Can I use cooking oil as a dormant oil?
Post by: CliffordK on 13/02/2013 04:18:28
Can I use cooking oil as a dormant oil?

Ok, so I'm a bit behind on spraying my orchard, and really don't relish the idea of lots of chemicals on my fruit trees.

I was browsing at the local building store, and they had "dormant oil" that was 96% canola (rapeseed) oil, & 4% unnamed "other ingredients". 

One is supposed to spray the oil with water (I thought oil and water didn't mix). 

Anyway, is there any reason why I should pay for $12 a quart for canola based dormant oil, when I can pay $2.88 for a quart and a half of 100% canola oil in the grocery store?

Should I add a detergent (dish soap) to help it spray & mix with water?  4% detergent?
Title: Re: Can I use cooking oil as a dormant oil?
Post by: menageriemanor on 13/02/2013 08:41:15
I believe that is called white oil, in Oz, for fruit tree spraying.  Is it for thrips and fruit tree 'rust?'  Yes, there is a homemade recipe,  I have never used old cooking oil, used fresh oil, water and a few drops of detergent, but infuriatingly, I can't remember the ratio.  Any radio gardening show will rattle it off, any permaculture forum.  You chuck it in a spray bottle shake it until it goes white, shake it regularly, so it doesn't start to seperate out.

You could try googling homemade recipe for white oil.

Just googled.  This is from a lovely Oz gov tv gardenng show, and the writer, Jerry Colby or similar, worked for the Brit Hort Society or somesuch.  He is also a great enthusiast of organic gardening.

http://www.abc.net.au/gardening/stories/    s2281115.htm

(Hope this works, I'm computer illiterate). Sorry just read at the bottom of page, not allowed to reproduce without permission.  I've put a gap between the last slash and the next bit. Is that legal?  Just so you can confirm the following

He says

2 cups of oil.  He uses sunflower, so not genetically modified
1/2 cup washing up liquid.

This is CONCENTRATED and will last 3 months. Store dark and cool.

TO USE

Take 2 dessertspoons full of the shaken concentrate to 1 litre of water, shaking again.

If you use a petroleum oil, more expensive, it will not block leaf pores if over 30 degrees celsius. Do both sides of leaves, not woolly leaves, lettuce, etc, just broad leaved trees.
Title: Re: Can I use cooking oil as a dormant oil?
Post by: Bored chemist on 13/02/2013 20:59:26
Legally, I think this would count as making your own (unlicensed) pesticides and might be forbidden.
However, if you claim that the oil is a votive offering to the "spirits of the trees" then you are probably OK.
Not sure if it's the copr or bpd that applies in this case (and I doubt they would apply to an individual anyway)
http://www.legislation.gov.uk/uksi/1997/188/regulation/4/made
http://www.legislation.gov.uk/uksi/2001/880/contents/made



Title: Re: Can I use cooking oil as a dormant oil?
Post by: CliffordK on 13/02/2013 21:30:33
Legally, I think this would count as making your own (unlicensed) pesticides and might be forbidden.

I'm doubtful that there could be any prosecution for use of such a product on a home orchard without any fruit being sold.  One should be able to demonstrate that vegetable oils and kitchen detergents have less of an impact on soil and groundwater than the petroleum alternatives.  Some finds its way into the septic tank anyway, so it can't be too bad in the ground and drainfields.

Vegetable oils, of course, do tend to decompose rapidly when exposed to moisture (part of the application process), but, again this is a very natural process.  And, the goal, of course, is to do this prior to blooming and fruiting., or possibly early in the fruit bearing season.

I'm also seeing Neem Oil (http://en.wikipedia.org/wiki/Neem_oil) being used as another organic alternative with additional biocidal properties beyond what is found in Canola and cooking oils.