Symptoms
The cobs of K-deficiency plants are narrowed and peaked. Grains in the cob tips are only poorly filled.
Reasons
Potassium deficiency (cobs at the right side)
Maize - Growth retardation
Symptoms
The cobs of K-deficiency plants are narrowed and peaked. Grains in the cob tips are only poorly filled.
Reasons
Potassium deficiency
Similar leaf symptoms may be caused by manganese or phosphorus deficiency, which also result in chlorosis, followed by necrosis. However, Mn deficiency is visible on younger leaves first.
Magnesium deficiency causes interveinal chlorosis with necrotic zones later, too, but these are spread over the whole leaf area and do not concentrate on the leaf tip or margin.
Salt stress due to overfertilization may also be a reason for marginal scorching.
Maize - Size reduced
Symptoms
Cob size is reduced and filling on cob tip is not complete
Reasons
Potassium deficiency on cobs (right)
Maize - Chlorosis
Symptoms
Yellow/bronze stripes and spots occur on the marginal area between the veins. Leaf scorch starting on leaf tips and margins spreads over the leaf blade with progressing deficiency.
Reasons
Potassium deficiency
Similar leaf symptoms may be caused by manganese or phosphorus deficiency, which also result in chlorosis, followed by necrosis. However, Mn deficiency is visible on younger leaves first.
Magnesium deficiency causes interveinal chlorosis with necrotic zones later, too, but these are spread over the whole leaf area and do not concentrate on the leaf tip or margin.
Salt stress due to overfertilization may also be a reason for marginal scorching.
Maize - Chlorosis
Symptoms
Yellow/bronze stripes and spots occur on the marginal area between the veins. Leaf scorch starting on leaf tips and margins spreads over the leaf blade with progressing deficiency.
Reasons
Potassium deficiency
Similar leaf symptoms may be caused by manganese or phosphorus deficiency, which also result in chlorosis, followed by necrosis. However, Mn deficiency is visible on younger leaves first.
Magnesium deficiency causes interveinal chlorosis with necrotic zones later, too, but these are spread over the whole leaf area and do not concentrate on the leaf tip or margin.
Salt stress due to overfertilization may also be a reason for marginal scorching.
Maize - Deformation
Symptoms
The cobs of K-deficiency plants are small and peaked. Grains in the cob tips are only poorly filled.
Reasons
Potassium deficiency
Similar leaf symptoms may be caused by manganese or phosphorus deficiency, which also result in chlorosis, followed by necrosis. However, Mn deficiency is visible on younger leaves first.
Magnesium deficiency causes interveinal chlorosis with necrotic zones later, too, but these are spread over the whole leaf area and do not concentrate on the leaf tip or margin.
Salt stress due to overfertilization may also be a reason for marginal scorching.
Potassium deficiency made worse by
Acidic soils (low pH)
Sandy or light soils (leaching)
Drought conditions
High rainfall (leaching)
or heavy irrigation
Heavy clay (illite) soils
Soils with low K reserves
Magnesium rich soils
Potassium is important for
Healthy, green foliage
Better root growth
Increased yields
Yara recommended fertilizers for Potassium
YaraVita TRACEL BZ
Maize: 1 to 2 kg/ha. Repeat up to 3 times at 10 to 14 day intervals as necessary. Avoid applications during flowering. Also, apply as necessary to perennial fruit crops post-harvest. Water rate: 200 l/ha minimum.