Re: CULT: PBF ... sort of
- Subject: Re: [iris-talk] CULT: PBF ... sort of
- From: o*@aol.com
- Date: Wed, 28 Aug 2002 13:14:47 EDT
In a message dated 8/28/2002 2:33:47 AM Central Daylight Time,
sil1812@molalla.net writes:
> Very much the antithesis of your description. I don't recall whether
> or not soil mineral content was discussed as a possible factor in the depth
> or lack thereof in PBF. I think we did cover about every other possible
> determining factor. <G>
>
These are the more obvious nutrient factors I see.
Phosphorous (P) or phosphate shortage in many plants causes reddish-purple
coloration in leaves, particularly young plants. Potassium (K) or potash aids
in the formation of anthocyanin (red color) in the leaves.
The uptake of both nutrients are affected by soil pH. (P) uptake is low below
pH 6 as is (K) though (K) uptake is not as sensitive at this pH level.
(P) uptake begins tailing off at pH 7.5 and does so until the pH reaches
8.75. At this point it becomes normal (same as at 7) at least until pH 10 is
reached. I have no idea why this occurs.
(K) uptake continues unfettered throughout the pH range from pH 6 to pH 10.
Additionally, the uptake of iron, manganese, copper and zinc (micro
nutrients) are curtailed at pH above about 7.5.
Obviously, understanding of the phenomenon where a specific iris variety has
an abundance of PBF in one area and little or none in another requires that,
as a minimum, we have accurate soil analysis data from each location along
with the corresponding soil pH. Preferably the analysis would be from the
precise micro climate in which the cultivar is growing.
The (P) and (K) considerations above are generalizations for a broad range of
crops as a whole and not irises specifically. I know of no source for such
data on irises specifically.
That Silverberg guy sometimes causes my mind's hard drive to need
defragmenting. <g>
Smiles,
Bill Burleson 7a/b
Old South Iris Society
[Non-text portions of this message have been removed]
------------------------ Yahoo! Groups Sponsor ---------------------~-->
4 DVDs Free +s&p Join Now
http://us.click.yahoo.com/pt6YBB/NXiEAA/MVfIAA/2gGylB/TM
---------------------------------------------------------------------~->
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
