Re: [CH] Foliage changing color
harryo@dave-world.net
Sun, 22 Feb 1998 08:41:33 +0000
I do not remember the original post, describing the symptoms, but
yellowing plants could indeed be a sign of chlorosis. However, one
of the more common types, is iron chlorosis, which is caused by soil
that is too alkaline, not too acidic. The high pH ties up available
iron and makes it unavailable to the plants. Overwatering, poorly
drained soils, damaged roots and too high of levels of manganese,
copper or zinc can also contribute to iron chlorosis problems.
If the soil is too alkaline, lowering the pH by adding ammonium
sulfate or sulfur can correct it. Adding chelated iron to the soil
or applied as a foliar spray will give a quick fix, but not a
permanent one.
Note that the symptoms of iron chlorosis are often confused with
deficiencies of magnesium, manganese , boron or other possible
non-nutrient related problems. Some viral diseases also have similar
symptoms.
Harry
> Date: Sun, 22 Feb 1998 08:11:38 -0500
> From: "Robert Farr, Chile Man" <rbfarr@erols.com>
> Subject: Re: [CH] Foliage changing color
> Doug:
>
> Sounds like your plants may have chlorosis - an inability to
> photosynthesize. You soil could be tying up nutrients. Perhaps it's
> the wrong pH for veggies.
>
> Vegetables require a pH range of 6 - 7 (I think the perfect pH for
> veggies is 6.2). So, make sure you've planted in a good, sterlie
> potting medium (vermiculite, perlite, peat, etc. - something like
> Hyponex).
>
> In the interim, yous should use a fertilizer high in nitrogen. Soils
> which are too acidic (low pH) tie up nitrogen (and calcium and
> maganesium, among other macronutrients. A lack of calcium inhibits the
> ability of the soil to use magnesium - which can cause some forms of
> chlorosis).
>
> Harry Jiles - is that the way you see it, too?
>
> Robert.
>
>