- Apples
- Banana
- Barley
- Beans
- Broccoli
- Cabbage
- Citrus
- Grassland & Pasture
- Lettuce
- Maize
- Oilseed Rape
- Plums
- Potatoes
- Raspberries
- Rice
- Soybean
- Strawberries
- Sugarcane
- Table Grape
- Tomato
- Wheat
- Wine Grape
Lettuce - Deformation
Symptoms
Tips and margins of older leaves get chlorotic spots with increasing size which become necrotic later on. On account of scorched leaf margins leaves are deformed.
With more severe deficiency the leaf color turns to mottled dark green and the plant appears wilted. Occasionally leaves are less crinkled than normal and shape of the leaves becomes more rounded.
Growth of the plants is restricted, they do not form heads or the heads remain loose.
Reasons
Potassium deficiency
Symptomes may be confused with high salt concentration of the growing substrate. In this case the veins of the leaves become brown in addition to dry leaf margins.
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
- Internal water regulation
- Vigorous growth and healthy foliage
- Required in large amounts