Trial harvest figures for main harvest show advanced crop

Aviko Potato samples annually a series of ware potato plots in the Netherlands. No distinction is made between regions and races. The gross yield per hectare for week 30 is about 42 tons in the size 40 millimeters upwards. That is almost equal to the result of 2017, which is also the top year in the chart over the last five years. It is about 10 tons more than in, for example, the dry years 2018 and 2020.

High underwater weight
If we look at the percentage 50 millimeters upwards, the sampled batches are relatively coarse with about 70% coarser than 50 mm. This also places the parties high in the five-year average. This is also the case for the underwater weight. It comes out at 390 grams or a little more. Only in 2019 was that slightly higher with more than 400 grams. This means that the crops are already relatively well developed before the end of July. Over time, this content may still decrease somewhat, as was visible in 2018.

Aviko is one of the first to publish figures for the main harvest. Also the Crop tour Potatoes will be sampled shortly. The picture for Innovator potatoes is variable and strongly dependent on the region and the planting moment. The crops have survived relatively well for two days of extreme heat, but persistent drought and temperatures above 25 degrees cause wear and tear.

Also PCA en fiwap have published the first figures for the Fontane variety in Flanders and Wallonia, together with a number of colleague organisations. This concerns eighteen plots in Flanders and fifteen in Wallonia. The first sampling of these 25 plots was carried out on 26 and 33 July. After 96 growing days, the gross yields fluctuate between 20 and 43 tons per hectare. The average is 30,8 tons per hectare. A single plot stands out in a negative way. Half of the Flemish plots have not yet reached 30 tons per hectare. In Wallonia, the average is slightly higher at 32,5 tons. This also applies to the sorting 50 mm upwards.

Drought mainly consequences in Flanders
Especially in Flanders, the drought has consequences for the yield. The growth curve starts below the multi-year average. The Walloon figures raise that average slightly, so that the first yield measurement is still on the line with the multi-year average. It should be noted that the crops in Wallonia are further developing. The foliage has deteriorated further than in Flanders, where up to 10% of the foliage has now matured. There are outliers of up to 30%.

Underwater weights are extremely high for late July, PCA notes. On average, all plots amount to 406 grams, with a range between 344 and 465. The underwater weights between Flanders and Wallonia are the same. Four out of ten plots have an OWG higher than 400 grams. Through-wash was not found in Fontane during the sampling, just like wastage.

Was on the lookout
The current situation with high underwater weights calls for timely treatment with MH (maleic hydrazide). MH spraying has often already been applied to early French fries varieties such as Innovator, but the high temperatures did not always make this easy, so that spraying was not carried out in time everywhere. Insiders report that the first signs of washing through are already visible. PCA also reports through washing in Bintje, where the MH spraying should have already been carried out. Because MH has to be sprayed on a vital crop, a rapid decline of the plants is not ideal, especially in combination with high temperatures.

Thunderstorms are expected later this week that could provide significant local precipitation. If the crops go through a growth spurt, then there is a strong threat of overwashing. Experience has shown that MH can also be applied at higher temperatures, but the crop must still be vital for this. For those who have not yet carried out spraying, the timing is crucial.