Iron

Iron is needed for chlorophyll formation, plant respiration and the formation of some proteins.

Iron deficiency first appears as yellowing between the veins of the newest growth. The veins will remain green except in extreme cases.

There is no OMAFRA-accredited soil iron test. An iron soil test does not correlate well with plant uptake or fertilizer response in Ontario. Plant analysis is a much more reliable indicator of iron availability.

Iron deficiencies are rare in Ontario. Factors associated with iron deficiency in other parts of the world are extreme imbalances with other metals such as molybdenum, copper or manganese. Excessive phosphorus in the soil may also contribute to iron problems. Soil with low organic matter or a combination of high pH, high lime, and wet cold soils can induce iron deficiency symptoms in sensitive crops.