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About the effectiveness of ethylen compared with carbide for pineapple forcing: Abeless (1973) mentionned that physiological effects of acetylen on plants are similar to those induced by ethylen but needs higher concentrations. Practically if we take into account the recommendations in CI by Cirad for forcing : 500g carbide in 150L (with 50ml /plant) and 800g ethylen / 7000L on 67000plants , we have theoritically 11mg ethylen/plant and about 55mg acetylen/plant for the same result. But ethylen solubility is very low in water (so need to add activated charcoal to retain it in the solution) meanwhile actylen solubility is about 2g/L and increases in cold water. Consequently the amount of ethylen effectively applied is much lower than 11mg mentionned before. Using dry activated charcoal we managed to have good results with 2 to 3mg of ethylen / plant.
As Duane said, both solutions are very effective on sensitive varieties. Nevertheless, in some case sensitivity may drop in all varieties due to specific climatic conditions and /or amounts of fertilizer applied.
I confirm the observation that MD2 sensitivity to phytophthora maybe a problem after carbide forcing....
-------Message original-------
Date : 25/08/2009 12:57:37
Sujet : OPWG Digest, Vol 17, Issue 10
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Today's Topics:
1. Re: Flower induction in organic pineapples
(Organic Pineapple Working Group)
----------------------------------------------------------------------
Message: 1
Date: Tue, 25 Aug 2009 08:14:11 -0000
Subject: Re: [OP] Flower induction in organic pineapples
Message-ID: <000f01ca255c$08c09c20$1a41d460$@org>
Content-Type: text/plain; charset="iso-8859-1"
In Ghana we have done some (small trails) that suggest that ethylene gives
around 5% better induction than carbide (but both in the 90+% region. There
are some agronomists who believe that carbide should be avoided in MD2, as
the pH of the carbide solution seems to increase phyotphora (of which MD2 is
very susceptible); however this is from observation only and there are no
trial results to my knowledge on this. Most commercial (non-organic) farms
in Ghana now use ethylene, having switched from carbide. All (four)
commercial non-smallholder organic certified farms in Ghana use ethylene -
as they have no choice.
-----Original Message-----
On Behalf Of Organic Pineapple Working Group
Sent: 24 August 2009 23:38
To: Organic Pineapple Working Group
Subject: Re: [OP] Flower induction in organic pineapples
Most pineapple growers in Mexico prefer Calcium Carbide due to it's
lower cost, greater availability and effective results on Smooth
Cayenne when DISOLVED IN ICE WATER AND SPRAYED ON AT NIGHT.
(That's how it's done).
Duane Bartholomew posted:
> Regarding indications that ethylene is more effective than carbide
> (acetylene), if there is a difference, it probably isn't relevant
> where growers plant MD-2 or another sensitive (easy to force)
> cultivar.
> Carbide is widely used by growers in Ghana and Taiwan and probably
> elsewhere because it is cheap and easy to use and is very
> effective.
And highly explosive.
> In fact, I don't think the issue of whether acetylene or ethylene
> is more effective has ever been settled. I am not aware of any
> papers where a direct comparison has been made after people
> learned how to use both materials effectively.
As whether pineapple forced using calcium carbide can be certified
as organic:
As mentioned earlier, permitting either substance would have to be
allowed as an exception to the general rule, and what is permitted
by one country's market may vary from the substances and procedures
permitted or prohibited by another.
Since certification by an accredited third party agent has become
the key to selling a product as organic, I strongly suggest that
anyone planning on selling their pineapple in the organic market
check with their certifier before using any manufactured product.
Regarding IFOAM:
Although IFOAM is considered to be the highest organic authority by
many, IFOAM regulations are not taken into account by the USDA and I
suspect, the same is true for the ECM.
Finally, the availability of a procedure or naturally occurring
substance or capable of inducing florescence in pineapple could
cause organic authorities to withdraw their approval for synthetic
ethylene and calcium carbide, where those exist.
Douglas Hinds
OPWG Chair
Director General
Center for Community and Rural Development (CeDeCoR, A.C.)
Coordinador
Alianza para la Responsabilidad Ecol?gico y Social en el Desarrollo
(Alliance for Ecological and Social Responsibility in Development)
Mexico
> ----- Original Message -----
> Date: Monday, August 24, 2009 2:56 am
> Subject: Re: [OP] Flower induction in organic pineapples
>
>
>> Calcium Carbide is not allowed under IFOAM regulations. Only ethylene
gas is allowed. However, there are indications that ethylene is more
effective than carbide.
>>
Working Group
>> Sent: 20 August 2009 03:28
>> To: Organic Pineapple Working Group
>> Subject: [OP] Flower induction in organic pineapples
>>
>> I am not sure how acceptable carbide stones are. As far as I know, on
contact with water, carbide liberates acetylene gas which is an analogue of
ethylene. Certain unacceptable impurities are also known to be present in
tcarbide.
>>
>> Would like your comments.
>>
>> Shanthi
>>
>> -------Original Message-------
>>
>> From: Organic Pineapple Working Group
>> Date: 8/19/2009 6:21:29 PM
>> Subject: Re: [OP] OPWG Digest, Vol 17, Issue 1
>>
>> Currently there is the use of carbide stones. I am not positive on the
source of this carbide, or the chemistry. It releases ETHYLENE gas upon
contact with moisture.
>>
>> > Subject: OPWG Digest, Vol 17, Issue 1
>> > Date: Tue, 18 Aug 2009 16:57:02 -0400
>> >
>> > Send OPWG mailing list submissions to
>> >
>> > To subscribe or unsubscribe via the World Wide Web, visit
>> > or, via email, send a message with subject or body 'help' to
>> >
>> > You can reach the person managing the list at
>> >
>> > When replying, please edit your Subject line so it is more specific
>> > than "Re: Contents of OPWG digest..."
>> >
>> >
>> > Today's Topics:
>> >
>> > 1. Re: Pineapple News No. 16 (Organic Pineapple Working Group)
>> >
>> >
>> > ----------------------------------------------------------------------
>> >
>> > Message: 1
>> > Date: Fri, 14 Aug 2009 16:16:11 +0530
>> > Subject: Re: [OP] Pineapple News No. 16
>> > Content-Type: text/plain; charset="iso-8859-1"
>> >
>> > Dear Duane,
>> >
>> > I wonder if you would be able to help with information on organically
>> > acceptable methods for flower induction.
>> >
>> > Best regards,
>> >
>> > Shanthi
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