The first figures of the follow-up inspection in the seed potatoes will be negative this autumn. The results show many virus reactions, including many in young tribes and higher classes. In addition, many re-checks are requested, which means it can sometimes take longer before results are known.
In total, the national reduction percentage at the Dutch General Inspection Service (NAK) is approximately 35%, several insiders say. This means that the reduction is already considerably higher than the record year 2018, which ended the follow-up audit with a reduction percentage of 25,2%.
The figures are disappointing, but the fact that so much has been reduced does not come out of the blue in the seed potato sector. After the late planting in the spring and the early and very heavy aphid pressure when the plants were barely above the surface, infection already occurred frequently. The virus is then barely or not visible in the leaf and the drought that followed did not make the selection easy. Later in the growing season, primary virus was regularly found in various varieties. That really set off the alarm bells.
No arrow to draw
A tour of the seed potato sector shows that there is no point to be drawn regarding the results of the follow-up inspection. The potato Y virus is frequently found in both young stems (such as second year) and old ones. Where nothing was visible in the field, the follow-up checks are very disappointing and it is suddenly an E or an A. Even in varieties that have a reasonable tolerance to the virus, more reactions are counted by the NAK than in other years. This year, for the first time, the leaf roll virus will be tested again, which is making a new appearance in potato cultivation. The virus seemed to have almost disappeared, but has become more common in recent years. That is why the NAK has started testing this again.
The many reductions in seed potatoes lead to many re-inspections at the NAK and the taking of enlarged virus samples. These requests take up a large part of the available processing capacity and this results in longer processing times. Especially for varieties that have to be shipped early for export, there is time pressure behind them and they are brought forward. In addition, the balance must be drawn up for certain breeds to determine how many tonnes there are of a class. Class E or A can make a big difference in overseas export opportunities. In addition, the potatoes are generally longer and more deformed than in other years due to the extreme growing season, which means that testing takes more time. On average, an investigation takes about 25% longer.
Headaches seed potato grower
The current reduction percentage does not make planning the seed potato area for next year any easier. Certainly the virus reactions in the younger vintages mean that a grower has to choose other varieties or make purchases. Planting out a batch with a lot of virus entails a lot of risk and can also be a source of virus transmission to other varieties during the season. In addition, the 'least' virus responses will have to be examined in some breeds in order to maintain the proportion of higher classes.