Even the robust bulbs are not spared from diseases and pests. By skilfully selecting the location and the neighbors in the bed, infestation can be prevented.
Wrong mildew
Downy mildew is the most common onion fungal disease that can occur in persistently damp and cool weather. The spores of the fungus are carried by the diseased bulbs or emerge from the soil where they are left over from the overwintered plants.
The clinical picture manifests itself in the fact that the foliage changes colour. However, the discoloration is initially difficult to notice, so that it can spread unhindered. If the infestation progresses, the leaves die off and the tuber has a hard time growing.
Preventive measures:
- When buying seeds, pay attention to the resistant varieties
- water the plants in the morning or afternoon if possible, so that the moisture does not get on the leaves overnight
- airy garden space is important
- do not arrange the rows too closely so that the plants have more space
onion fly
The onion fly is an aggressive pest that lays eggs on young plants from April. The maggots that hatch from it damage the onion by eating into it. The onion fly hatches two to three times a year. The first generation is the most dangerous because the young seedlings are just developing and not robust enough.
You can recognize the infestation by the fact that the young plants wilt first and then their green dries up. The onions are starting to rot. You notice it above all by the fact that you can easily pull the onions out of the ground.
The best way to avoid fly infestation is to use protective nets stretched over the beds. This is particularly important in the period from sowing in April to the formation of the tubers in June, as the growing seedlings are not yet resistant at this point. A direct proximity to carrots should also have a favorable effect. Furthermore, one should not overdo it with the fresh organic fertilizer.
tips and tricks
The onions are spared one annoying pest: the snails don't like the onions, they are probably too hot for them.