field
shot - Springhill, MT, 1955
Pictures of nitrogen deficiency:
field
shot - Springhill, MT, 1955
chart
- how soil pH affects availibility of plant nutrients
liquid
fertilizer burn - in wheat plants
Symptoms of nitrogen deficiency:
1) Reduced tillering
2) Reduced root mass
3) Smaller leaf size
4) Lower leaves turn yellow and died from the tip back
5) Stunted growth and reduced tillering
6) Adverse effect on spikelet formation, floret formation, kernel fill, and grain protein (1).
Look-alike symptoms:
5) Herbicide injury due to:
a) Acetanilides (Stampede)
b) Imidazolinone symptoms on leaf tips (Assert, Pursuit, Scepter)
c) Sulfonylurea symptoms on leaf tips (Accent, Ally, Amber, Beacon, Classic, Express, Glean, Muster, Pinnacle, Refine)
d) as-Triazines (Lexone, Sencor)
e) s-Triazines (Aatrex, Atrazine, Bladex) (1).
Favorable conditions:
1) Lack of available nitrogen due to excessively wet soils in the growing season.
2) Dry soils, sandy soils, and soils low in organic matter
3) Intensive cropping with little or no fertilizer, forage or legume rotation, or animal manure added back to the soil (1).
Pattern in field:
1) Nitrogen deficiency generally occurs in areas of soil compaction or high crop residue which may tie up available nitrogen early in the growing season (1).
2) Symptoms also can appear on sandy ridges, eroded hilltops and areas
where water has accumulated and leached the nitrogen out of the root zone
(1).
Infestation levels: Improved growing conditions and application of additional nitrogen can help with recovery (1).
History in MT and US:
Crop losses:
Controls:
Cultural controls:
Resistant varieties:
Biological controls:
Chemical controls:
References: 1) Guide to Herbicide Injury Symptoms in Small
Grains. Second Edition. 1992. Agri-Growth Research, Inc., Hollandale,
MN, pp. 69-70.
Symptoms of phosphorus deficiency:
1) Reduced root system
2) Stunted growth and poor tillering
3) Increased susceptibility to winter injury and moisture stress
4) Purpling of stems and lower leaves
5) Delay of heading and crop maturity (1).
Look-alike symptoms:
1) Low pH
2) Wet soil or weather stress
3) Russian wheat aphids
4) Herbicide injury due to:
a) Aryloxphenoxy-propionic acids/cyclohexanediones (Achieve, Assure, Assure II, Excel Super, Fusilade 2000, Fusilade II, Hoe-Grass, Hoelon, Option II, Poast, Select)
b) Dinitroanilines (Edge, Prowl, Sonalan, Treflan) (1).
Favorable conditions:
1) Insufficient phosphorus availability to the plants
2) Phosphorus deficiency also can be caused by factors that inhibit root growth such as:
a) cold, wet or dry soil,
b) compacted roots,
c) root damage by herbicides,
d) insects,
e) root rots, and/or
f) varieties that have initially weak root systems (1).
Pattern in field: Areas in a field most likely to show injury are ones with:
1) Low organic matter,
2) Light-colored soils,
3) Calcareous soils, or
4) Compacted or wet soils (1).
Infestation levels: Plants generally will recover when growing conditions are favorable and allow for root expansion.
Leaf symptoms may disappear with phosphorus applications (1).
History in MT and US:
Crop losses:
Controls:
Cultural controls:
Resistant varieties:
Biological controls:
Chemical controls:
References: 1) Guide to Herbicide Injury Symptoms in Small
Grains. Second Edition. 1992. Agri-Growth Research, Inc., Hollandale,
MN, pp. 71-72.
Symptoms of sulfur deficiency:
- Overall yellowing and stunting.
- Lower leaves on sulfur-deficient plants remain a pale green, while the lower leaves of nitrogen-deficent plants die as nitrogen is redistributed to newer leaves.
- Upper leaves in advanced stages change from yellow to white (1).
Look-alike symptoms:
1) With nitrogen deficiency, the lower leaves turn yellow and die as nitrogen is redistributed to newer leaves, while the lower leaves on sulfur-deficient plants remain a pale green.
4) Herbicide injury due to:
a) Aryloxphenoxy-propionic acids/cyclohexanediones (Achieve, Assure, Assure II, Excel Super, Fusilade 2000, Fusilade II, Hoe-Grass, Hoelon, Option II, Poast, Select)
b) Imidazolinones (Assert, Pursuit, Scepter)
c) Isoxazolidinones (Command)
d) Sulfonylureas (Accent, Ally, Amber, Beacon, Classic, Express, Glean, Muster, Pinnacle, Refine) (1).
Favorable conditions:
- High precipitation:
The higher the precipitation, the greater the probability that sulfur is limiting crop growth. This is because the form of sulfur that is used by the plants is the sulfate ion. Sulfate is very soluble in water and leaches easily - especially in sandy soil.
- Sandy or low organic matter soils:
Most sulfur is present in soil organic matter. When soil microbes decompose
this organic matter, the sulfur is released. As a result, soils that are
sandy or low in organic matter are most prone to sulfur deficiency (1).
Pattern in field: Areas in a field most likely to show injury are those that are:
a) Well-drained and/or low in organic matter, and/or
b) In areas where greater rainfall occurs (1).
c) In areas of fields with high levels of organic matter such as chaff rows from previous crops.
Infestation levels: Plants can recover if sulfate is applied before jointing (1, MB). Once jointing occurs, the yield potential is already determined and application of sulfur will not be beneficial.
History in MT and US: In 1994, sulfur deficiency was prominant in former chaff rows in several fields in Gallatin County. 1993 had been an especially wet year causing more sulfur leaching than normal. In the chaff rows, the higher residue levels tied up more of the remaining sulfur than did the areas of the field with less organic matter.
Crop losses:
Controls:
Cultural controls: Apply sulfate forms of sulfur since elemental sulfur would require biological oxidation for conversion to sulfate. Most growth of cereals occurs when soils are cool and microbial activity is low. As a result, minimal oxidation of elemental sulfur occurs. Therefore, if elemental sulfur is used, it should be applied in the fall when soil temperatures are relatively warm (1).
Resistant varieties:
Biological controls:
Chemical controls: See cultural controls above.
References: 1) Guide to Herbicide Injury Symptoms in Small Grains. Second Edition. 1992. Agri-Growth Research, Inc., Hollandale, MN, pp. 73-74.