Role of Magnesium in Onion Production
Magnesium is required for many processes including transfer of energy and protein synthesis.
With 20-25% of the plant’s total magnesium localized in the chloroplasts, it is particularly important for chlorophyll production.
Trials in South Africa show that magnesium, applied alongside calcium, helps to improve the shelf life of onions by reducing the level of rots during storage.
Magnesium effect at growth stages
| Stage | Magnesium effect |
| Vegetative Growth | Maintain vigorous, healthy leaf growth and to build plant supplies prior to bulbing |
See more on Onion Growth Stages.
General Guidelines for Magnesium Application
Onions crops use relatively low levels of magnesium. Nonetheless, a regular supply is needed throughout the life of the crop. Particular care is needed in fertigation systems to ensure that magnesium, potassium and calcium are balanced.
Magnesium Deficiencies in Onion
Older leaves turn a uniform yellow along their entire length due to lack of chlorophyll. Leaves can exhibit pale lesions on leaf tips.
