Above ground, the foliage development of potatoes is fairly normal, but underground tuber setting is limited to a few tubers per plant. This picture of potato crop development applies to a quarter to a third of the plots in Zeeland, estimates sector manager arable farming Wim in 't Veld of Van Iperen.
Elsewhere in the Netherlands, for example in Flevoland and Groningen, the picture that Van Iperen employees get when determining the timing of spraying with germination inhibitor MH is not much better. "To determine this moment, plants are pulled up. It then becomes visible that sometimes there is hardly even any tuber formation."
Changeable weather forecast
The extreme spring drought has also left its mark on the plots that have been irrigated. Although the rainfall from the end of June on plots that have not been irrigated has apparently saved crop development, it is still questionable whether yields are actually far below average this year.
Manager Eelco Boot of the De Rusthoeve experimental farm in Colijnsplaat keeps his spirits up. "The most important month of August is yet to come. The changeable weather forecast is favorable for the development of the potatoes."
Comparative irrigation test
In contrast to potato cultivation, Boot, like Van Iperen's employees, has given up hope for a normal yield of seed and onion onions. Irrigated plots are the exception. Even with irrigation, a normal yield will probably not be achieved this year, according to a test at De Rusthoeve. Drip and fertigation (drip irrigation of water in combination with fertilizers) seems to give the best results. Irrigation without fertilizers also gives a much better yield this year than the plots without treatment.