Whats Wrong with your Plants?


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Aug 5, 2006
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thought this was a very good article in HT.
by -Herb Green

The following simplified key should help you diagnose nutritional problems. This key is base on the fact that some elements easily move from one leaf to another inside the plant, while others are immobile and some are intermediate.

- If an element is mobile (nitrogen, phosphorus, potassium, sodium, magnesium, chlorine, sulfur) symptoms of its deficiency will be seen first in older, lower leaves, because it will be shifted up into newer growth where it is most needed.

-If an element is immobile in the plant, symptoms of its deficiency will be seen first in the younger leaves because it cannot be drawn to where it is needed. Immobile elements include iron, calcium and boron.

-In marijuana, old leaves have a natural tendency to turn yellow, dry up and wither away. This does not automatically mean the plant is short on nitrogen. However, if the whole plant takes on a lighter green to yellowish color that is most pronounced in its olderest leaves, it probably has a nitrogen deficiency.

-if the older leaves turn dark green and red or purple colors are seen in the veins, suspect a phosphorus deficiency.

-if you see older leaves becoming mottled, turning yellow and curling their leaf edges upward, consider a magnesium shortage

-if older leaves are mottled., yellowing and have necrotic spots at the tips and between the veins. a lack of potassium is probably the problem

-if the dead spots are generalized over the plant and rapidly enlarging and the stalks have shortened internodes, the plant could need zinc.

-if you see distortions at the tips or bases of the upper younger leaves, followed by the terminal bud shriveling up, the plant has a calcium deficiency.

-if yound leaves of the terminal bud turn bright green at the base and become twisted. suspect a boron deficiency. if the termnial bud turns warty and dies. you have too much boron.

-if young leaves wilt permanently without spotting or yellowing the problem could be a copper deficiency.

-if young leaves dont wilt but do turn yellow and show spots of dead tissue scattered over the leaf, the plant needs more magnese.

-if young leaves are light green and do not show dead spots chances are the plant is short of sulfur

-if young leaves start turning yellow and there are no dead spots present, a deficiency of iron should be suspected.

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