Symptômes
Edges and tips of the lower leaves become yellow and later necrotic. Eventually, the marginal yellowing spreads between the veins as the deficiency progresses. Leave margins curl up. The leaves often wither and collapse prematurely.
Plant growth is squat and stunted.
Raisons
Potassium deficiency
Symptômes
Potassium deficient tubers show black spots. When cut, they blacken rapidly.
The spots mostly occur near the vascular ring at the stolon end of the tuber.
Raisons
Black spot due to potassium deficiency
Symptômes
Edges and tips of the lower leaves become yellow and later necrotic. Eventually, the marginal yellowing spreads between the veins as the deficiency progresses. Leave margins curl up. The leaves often wither and collapse prematurely.
Plant growth is squat and stunted.
Raisons
Potassium deficiency
Symptômes
Edges and tips of the lower leaves become yellow and later necrotic. Eventually, the marginal yellowing spreads between the veins as the deficiency progresses. Leave margins curl up. The leaves often wither and collapse prematurely.
Plant growth is squat and stunted.
Raisons
Potassium deficiency
Potatoes: One application of 10 l/ha or two applications of 5 l/ha during tuber bulking (as soon as first-formed tubers are 10mm in diameter). Allow 10 to 14 days between applications. A further application of 5 l/ha may be made following petiole analysis, during tuber bulking. Water rate: 200 l/ha.
En savoir plus YaraVita FOLIAR POTASHPotatoes: To increase tuber number, 10 l/ha at tuber initiation (when 50% of the tip swellings are twice the diameter of the rest of the stolon). To increase tuber size a minimum of 2 applications of 5 l/ha or 1 to 2 applications of 10 l/ha during tuber bulking (as soon as first formed tubers are 10 mm in diameter). Allow 10-14 days between applications. Water rate: 200 l/ha
En savoir plus YaraVita MAGPHOS K