How to maximise onion dry matter content

Nitrogen form influences onion dry matter

Trials confirm that a balance between nitrate and ammonium-N is most effective at promoting onion leaf and bulb growth. However, during later stages of growth, nitrate forms provide higher dry matters in the bulb.

Potassium increases onion dry matter

Potassium is particularly important where high N rates have been applied (if high yielding systems). In these situations, increasing dry matter and sugar accumulation in the bulb helps maintain yield.