'Sowing onions in May gives leeks' is the saying. For many onion growers, however, it could not be any other way this season. Quite a few onions were sown this week. In some regions it seems to be a thing of the past whether sowing will succeed in the coming days.
Nationally, considerable catch-up is being made this week with sowing onions. Given the pace, it is difficult to estimate what percentage has been sown nationally, but after some inquiries we can roughly say that this is probably around 80%. However, sowing does not always take place under the desired conditions, given the soaking wet subsoil.
Race against the clock
The first wave of onion sowing was already a bit later than average this spring. In the south - traditionally the earliest sowing - growers were forced to postpone sowing due to the high rainfall and low temperatures. In March, sowing was only done sporadically and it was not until mid-April that the national percentage sown increased sharply. This week, growers are working day and night, including the participants in the Onion Crop Tour. On the sandy and lighter soils almost everything is in it. In Flevoland the backlog is being made up well.
Heavy soils are not easy
But due to the wet soil, sowing is quite disappointing in some regions, says Frans van der Ploeg, onion specialist at Hazera. "It is mainly on the heavier soils where the soil is sometimes not yet suitable enough for sowing. Some plots are sown where it is not actually possible, but time is ticking." In some regions, a large number of plots still need to be sown. "On the heavier soil in North Holland, approximately 50% to 60% had been sown until Monday and if the weather forecast is correct, some will not be sown."
By then, mid-May will already be here and that is not desirable for growth, says Bart Schriever, Benelux sales manager of De Groot en Slot. "We communicate to our growers that May 10 is the last day for sowing. After that, you will not have enough growing days and the longest day, which determines the bulbing, is already very close. You must have at least three large developed pipes and preferably more to achieve a good yield. The onions that are sown now and grow quickly can certainly still achieve a good yield."
Van der Ploeg also indicates that sowing in May can still produce good yields. "Our tests last year show that onions sown in May can still achieve a yield of 60 to 70 tons per hectare." The choice of an early or late variety for late sowing also has a major influence. When sowing late, it is better to choose a late variety because it grows longer at the end of the season.