Manganese on Wheat
Topdressing of fertilizer to wheat this spring has just begun and while
Nitrogen, Phosphorous and Potash are most used in blends the micronutrient
Manganese should be considered either soil broadcast or more likely later on in
the season as a foliar feed.
Manganese is influenced by Ph, organic matter, poor aeration and other
nutrients. Nitrogen will have an acidifying effect therefore will increase
enhancement. However Manganese
deficiency will be mostly a problem in sandy soils and fields with high pH
above 6.5 combined with low organic matter. Muck soils will have Manganese
deficiency as well. Newly tiled fields will also show deficiency. Symptoms
appear as pale yellowing and stunting with grey-white specks on the lower
leaves. Since Manganese is water-soluble it is available with excessive water.
Also, Manganese is more available thru poor aeration therefore any slight
compaction such as the floater truck tracks the wheat will appear green. If
this occurs and the rest of the filed is pale yellow then it is a likely a
Manganese deficiency.
A foliar application of Manganese Sulphate at 8kg/ha is recommended. Foliar
application is recommended over soil applied because the latter is converted
into unavailable forms too rapidly. However soil applied Manganese may be used
in a low pH sandy soil situation. A
quick test can be performed by mixing some manganese sulphate in a spray bottle
and then proceed to spray a small area of the field. If manganese was deficient
them it will green up in a day. Spraying Manganese Sulphate by itself is
recommended as there maybe some antagonism with herbicides in the sprayer.
Manganese is involved in photosynthesis and chlorophyll production in plants
as well activates enzymes for growth regulators.
Your Co-op Crop Specialist in your area will help you scout your wheat
fields this spring, give us a call.
Sources: Soil Fertility Handbook(Pub. 611), 1998; Agronomy Guide for Field
Crops(Pub.811)
Clark Aitken
Crops Specialist
Orford Co-op
Muirkirk
