Nutrient deficiency (or toxicity) will usually produce abnormal looking
leaves. The appearance of such abnormalities often causes growers to
conclude that the nutrient is deficient in a particular element.
However, assuming a ‘complete’
nutrient formulation* is being used, nutrient deficiencies will
typically be caused by the following:
+
EC or
feed frequency is too low.
+
Nutrient is dumped too infrequently
(re-circulating systems).
+
Nutrient pH is inadequate.
+
Humidity is too high.
*Be aware of using nutrient formulations that do not offer a separate
formulation for vegetative
and flowering/fruiting phase.
Nutrient deficiency symptoms
Foliar symptoms can easily be confused with those caused by pests or
diseases. However, as a general rule, nutrient deficiencies (or
toxicities) yield ‘regular’ patterns on the leaf. For example,
'yellowing' of the veins. Pests and diseases however,
generally produce ‘irregular’ marks.