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Explosive increase in thrips in onions
The current weather conditions are causing an explosive increase in tobacco strips in onions, while the same conditions make it very difficult to choose whether or not to use Movento.
To bet Movento or not?
Is intervention necessary?
First check the crop for the presence of thrips. When you can now find thrips in the shaft of the onion, intervention is necessary. A high temperature ensures a rapid completion of the life cycle in thrips. The few thrips you find now can multiply into millions within a few weeks!
The only way to limit the damage this causes is to prevent the population build-up as early as possible.
Are the current weather conditions favorable for the control of thrips?
The conditions in which thrips cause problems are often conditions that are not optimal for combating thrips. The advice is now not to wait for the most optimal conditions when thrips are present, but to go for the best achievable conditions.
Recording important when using Movento
The active ingredient of movento (spirotetramat) only becomes effective against sucking insects after it has been absorbed by the plant. Movento works great on the larvae, but less so on adult thrips. There is no contact operation. The better the recording conditions, the more active substance can become effective and the better the result.
The growing point in the shaft is the place where most larvae hide and where most suction damage occurs. Movento is the only means in onion cultivation, which can be brought to this growing point due to the systemic properties. The better the growth, the better the systemic effect can be utilized.
Advice under the current critical circumstances
If possible, watering is definitely worth considering. The shaft of the onion is full of water, so that any thrips present will (temporarily) leave. Irrigation also ensures that the wax layer dissolves, which benefits the absorption of Movento, applied on the evening following irrigation. Finally, irrigation can contribute to better transport in the plant.
If irrigation is not possible or desirable, let the moment of application on warm days depend on the night temperature. On cooler nights (more dew) apply mid-evening. The moisture present at night helps with the absorption of Movento. On warm nights (little dew) use Movento at the end of the night/early morning.
Do not add any other resources to Movento. The recommended dose is 0,5 liters per hectare. Repeat the spraying once if you find live larvae in the onion shaft after 2 weeks.
