Attention is still the advice in the sowing onions. Syngenta's onion experts go through the state of affairs again and identify the points of attention for the period up to and including harvest. They also like to promote the national onion day of the UIKC on 25 August.
Michiel van Mol sees clear signs in daily practice that the seed onions are slowly moving towards the harvest. "There is some wear and tear in the crops and the first plots have already been ironed. This will soon apply to the vast majority of onion crops. And the very earliest plots of seed onions in the southeast have already been cleared." Fellow onion expert Kees Jacobs notes that there are significant differences in the condition of the seed onions. "The plots that are thin are on average a bit later. And on plots where the onions could not keep up with evaporation during the heat of early July, I come across a lot of yellow leaf tips. Where water has been irrigated, you see that much less. Anyway, In the end it's not about the leaf but about the bulb formation, which I don't think looks bad on average."
Thrips infestation has also led to considerable differences in the condition of the onions left and right, Jacobs sees. "The heat at the beginning of July was favorable for the propagation of thrips. The growers who then sprayed their plots on time, now have little trouble." The weather for the coming period also seems favorable for thrips, but Jacobs and Van Mol think that controlling the insect only has added value in crops that are still in full growth.
(Stop) watering
Now that the drought continues for the time being, the Syngenta onion experts see that the irrigation reels are working overtime again. "That in itself is not wrong", says Van Mol, "and for plots where the MD has only just been installed, it helps to keep the growth in there for a while. That is good for the transport of the MD "But if the onions start ironing seriously, it's better to stop irrigating. Ironed foliage provides entry ports for fungi and bacteria. And a humid climate at the bottom of an ironed crop favors downy mildew and leaf spots." Jacobs sees another threat. "We are again heading into the colder nights, which means there is a greater chance of dew forming. Last year, many growers missed out on this during this period. It is therefore crucial that you continue with the fungicide spraying until just before harvest."
Optimal harvesting moment
The stage at which the onions are harvested has a major influence on the skin quality in storage. Harvesting at 50% green foliage is the best time, say the Syngenta onion experts. "At that stage, not many kilograms are added and in many cases it is tare kilograms. Research by Uireka has shown this conclusively. A later harvest only leads to more bare onions and loss of color." Even if bad weather is expected, Jacobs and Van Mol advise to harvest anyway. "Two weeks in the swath is less bad than aging further in line."
Leaf blows are best done a fist-thick above the last leaf split, says Van Mol. "The remaining part of the pipes acts as a chimney for the drainage of moisture. If you fold too deeply, you will have problems with drying in the shed." As with the potato harvest, large drop heights, intensive shaking and many large clods are also taboo in onion harvesting. "The onion is more vulnerable than many people think," says Jacobs. "So make sure that the harvesting ash does not cause any damage." Drying in the swath is fine, but preferably bring the onions indoors if high temperatures are predicted, the Syngenta employees advise. "Bright sun also causes sunburn on onions", Jacobs knows. And if you store the product too warm, you also have to remove that heat from the batch. Otherwise you can't dry anymore."
Visit the onion day of the UIKC
It is always exciting whether it falls at a favorable moment. But if it is up to Jacobs and Van Mol, as many onion growers as possible will come to the national onion day of the UIKC on Thursday 25 August at the Rusthoeve in Colijnsplaat. "This is the most important event for onion cultivation in the Netherlands", according to the onion experts. "Everyone from the onion world is there and you can always get good information and share experiences with colleagues, researchers and the people of the seed companies." Visitors can expect the familiar set-up with a trial field excursion (including attention to drip irrigation and the insect problem), the information market and the mechanization field. In addition, a climate and energy square will be set up this year. And of course there is the traditional variety presentation. In that respect, Syngenta has something to celebrate this year. "Our Promotion variety is on the list for the first time this year", Jacobs reveals. "Anyone who wants to know more about our growing range of varieties is welcome for a good conversation. And we're also serving tasty burgers this year, so come by."