Soybean - Necrosis
Symptoms
Beginning on older leaves, numerous small brown spots give the plant a mottled appearance.
Furthermore, the blotches expand and coalesce to irregularly shapened, light brown necrosis.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Chlorosis
Symptoms
Interveinal yellow chlorosis, starting on the older leaf margins. The main veins remain green for some time.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Chlorosis
Symptoms
Interveinal yellow chlorosis, starting on the older leaf margins. The main veins remain green for some time.
As the yellowing progresses towards the leaf base, there appear brown marginal necroses.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Chlorosis
Symptoms
Interveinal yellow chlorosis, starting on the older leaf margins. The main veins remain green for some time.
As the yellowing progresses towards the leaf base, there appear brown marginal necroses. They may drie off and form a necrotic seam all along the leaf edge.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Chlorosis
Symptoms
Interveinal yellow chlorosis, starting on the older leaf margins. The main veins remain green for some time.
As the yellowing progresses towards the leaf base, there appear brown necrotic spots in the marginal area.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Chlorosis
Symptoms
Already far advanced chlorosis. The leaf is almost completely bleached, only the midrib and the adjacent area are still green.
As the chlorosis progresses towards the leaf base, there appear brown necrotic spots in the marginal area.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
Soybean - Deformation
Symptoms
Already far advanced chlorosis. The leaf is almost completely bleached, only the leaf base, the midrib and its adjacent area are still green.
As the chlorosis progresses towards the leaf base, there appear brown necrotic spots in the marginal area.
Leaves are bent down.
Reasons
Potassium deficiency
Large amounts of K are necessary for adequate nutrition of soybeans.
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
- Increased activation of enzymes and co-enzyme functions
- Improved protein synthesis
- Better stomatal function, turgor potential
