Selecting the right variety and transplanting it the right way does not always guarantee a bumper harvest in onion farming. Bulb onions, like any other crops, are affected by pests. What makes them cause even total failure to the whole crops is that it’s rare for the farmer to identify them, especially those that feed on the bulb in the soil.
In case you missed it, these are the key features of common onion varieties in Kenya.
Major onion pests
Onion flies (Onion Maggot)
- Most destructive at maggot stage. Maggots are white to cream in colour.
- Onion flies tend to eat the lateral roots causing tunnels into the taproots leading to shrivelling or dying of the plant.
- You can also find them inside developing onion bulbs which exposes them to infection by diseases like bacterial soft rot.
How to control Onion flies
- Practising early scounting helps in identifying and controling them early
- Practising regular crop rotation
- Using well-decomposed manure during planting
- Removing and destroying all infected plants
- Drenching with a high concentration of Thunder like 20ml in 20l of water or confidor insectisides before and after transplanting. Always remember that the soil should always be wet before drenching for the chemical to be effective.
Are you wondering how to raise your onion seedlings successfully? find out how to manage your onion seedbed correctly
Onion thrips
- Adult thrips are often slender with wings that are long, narrow and fringed with long hairs. Its nymphs are white or yellow.
- Both tend to feed on the base of the plant within the leaf sheaths. The attacked leaves have sunken silvery patches.
- Where the attack is severe, the entire plant appears silvery where the leaves wither, dry up or even die.
- The pest extract appears as black spots on the silvery leaves.
How to control onion thrips
- Proper irrigation as the water-stressed crop is highly susceptible to thrips damage.
- Keeping onion fields clean of weeds
- Uprooting and burning highly infested plants
- For organic farmers, spraying neem extract can help to control
- Early spraying of insecticides like Thunder OD 145 and Belt 450SC can help
Finally, read how to irrigate and unearth your bulb onions.
