Potassium deficiency in oilseed rape

Symptoms
Before specific symptoms occur, potassium deficiency causes growth and yield depressions of the plants. Younger leaves remain smaller, and later, growth of the plants is stopped. Specific deficiency symptoms occur on medium/older leaves first. They show chlorotic zones on the leaf margins which become necrotic later. The younger leaves get a blue-green colour.

Reasons
Potassium deficiency Mg deficiency also shows chlorosis and necrosis on older leaves, but these start from the middle part of the leaf whereas K deficiency symptoms occur on the leaf margins first.

Symptoms
Specific deficiency symptoms occur on medium/older leaves first. Starting from the leaf margin, chlorosis spreads over the leaf blade. Later on, the chlorotic zones along the leaf margins become necrotic.

Reasons
Potassium deficiency Mg deficiency also shows chlorosis and necrosis on older leaves, but these start from the middle part of the leaf whereas K deficiency symptoms occur on the leaf margins first.

Symptoms
Before specific symptoms occur, potassium deficiency causes growth and yield depressions of the plants. Younger leaves remain smaller, and later, growth of the plants is stopped. Specific deficiency symptoms occur on medium/older leaves first. Starting from the marginal area, the leaves become chlorotic and subsequently show necrotic spots and patches. The necrotic tissue can show a pale, light brown colour, similar to sun burn damage.

Reasons
Potassium deficiency Mg deficiency also shows chlorosis and necrosis on older leaves, but these start from the middle part of the leaf whereas K deficiency symptoms occur on the leaf margins first.