Re: Spathiphyllum Necrosis

["Ignace Vanluchene" <chb.ivl@innet.be>]

Hello Carl and Joel

The experience of Joel with the limestone-addition indicates that the
chlorosis and necrosis-problem  in Spathiphyllum really can be caused by
Magnesium deficiency.
To be sure you have to make leaf-analyses of the yellowing leaves , the
necrotic leafs and compare it to young adult leaves of the same plant.
Normally you will find out that the leaves whit the most damages have the
lowest Magnesium content, what means that there is a kind of cannibalism of
the plant on his adult older leaves to supply the Magnesium necessary for
new leaves.
To get the best results you take the top 10 cm and the 4cm near the margins
of the leaves .

Good luck
Ignace




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> Van: Joel Pesapane <pesapan@primary.net>
> Aan: FLORINET@agvax2.ag.ohio-state.edu
> Onderwerp: Re: Spathiphyllum Necrosis
> Datum: zondag 25 januari 1998 7:07
> 
> Carl Ford wrote:
> > 
> > Hello all,
> >    Am experiencing a problem with Spaths in interiorscapes that I am
not
> > sure about. Affects numerous varieties from Supreme down to Petite.
> > First shows up as blotchy yellow areas along margins of mature leaves,
> > mostly near and at the tip -- not many near petiole. Affected areas
> > progress to dark brown necrotic patchs along margins with narrow yellow
> > band between brown and green. New leaves develop nicely until they are
> > fully developed and hardened off, then begin blotching. Affected areas
> > progress slowly, if at all, and leaves will remain on the plant with
> > mostly green for extended period (months). It appears to be mostly a
> > cosmetic problem, as it does not appear to affect plant's overall
> > health, except for reducing photosynthetic area.
> >    Does anyone have any ideas on the the cause -- is it good old
> > flourine? And, more importantly, what can be done to eliminate or
reduce
> > it?
> >    Thanks!Carl:
> 	Just a note on some empirical data. We have always had the 
> same problem, not just us, but every interior plantscaper in the 
> area. We did an installation at the research facility of a world 
> famous chemical company in our area and they noted the necrotic areas 
> on the Spaths and asked me what the problem was. I related it to the 
> water quality in our area but told them I wasn't sure that that was 
> the problem. They told me that there was an easy way to prove my 
> hypothesis. They gave us access to an unlimited supply of de-ionized 
> water and we loaded our water machines from their tanks. Voila, no 
> more necrotic spots. If the cost were not prohibitive I would have 
> our technicians use nothing but de-ionized water and we could really 
> knock out the competition. Lacking that , I have found that the 
> addition of dolomitic limestone at the rate of one tablespoon per ten 
> inch pot, scratched into the media every four months, can tie up the 
> worst elements contributing to the necrosis. Make sure that you check 
> both the pH and the alkalinity of your water sources. Our water comes 
> out of the tap at a pH of almost nine but it is low in alkalinity so 
> that it is easily buffered. Hope this helps.
> 	Joel Pesapane
> > .
>  
> >
> >