ISSUE 11 July 13, 2000
CHLOROSIS IN OTHER CROPS
Although chlorosis is most commonly seen in soybeans and flax, other
crops are not immune. Growers have recognized it in dry beans nearly every year. Wheat is
a crop that we do not think about as being particularly susceptible to chlorosis, but the
last few years it has been seen in the wetter areas of the state. Iron chlorosis can be
recognized by a rather bright yellow coloring of the newer leaves. At close inspection,
the yellowing can be seen as striping or interveinal yellowing
of the leaf tissue.
It would be unusual and out of character for a whole field to affected. Do not confuse chlorosis with yellowing due to lack of nitrogen which is usually seen on bottom leaves first and moves up the plant as deficiency progresses, or sulfur, which results in a general plant yellowing. Neither of these deficiencies is seen as interveinal yellowing, but as yellowing of general plant tissues.
Iron chlorosis on wheat has recently moved west with the heavy rains in the northwest part of the state. If chlorosis is present, expect it to show up in wetter portions of the field which have a high soil carbonate content, particularly in the presence of soluble salts. These would be around potholes, or on hillsides in seepy areas. Make a note of varietal differences for future screening of varieties for use on your farm. Most of our varieties are very tolerant to chlorosis, but like soybeans, some differences should be expected. The chlorosis should leave when the soil dries and soil bicarbonate levels go back to normal.
Dr. Dave Franzen, NDSU
Extension Soil Specialist