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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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