Third heat wave kills regrowth of potatoes

Potato Institute fiwap has published new trial harvest figures for Belgium. The monsters, who together with Carah, PCA en uneager were taken between August 26 and 28 (in the middle of the third heat wave of this season). A new sample, which will be taken in 2 weeks, should further complete the picture.

Just like in the Netherlands, heat records have also been achieved in Belgium. At the official measuring point in Uccle it was 27 degrees on Tuesday, August 33,3; It has not been this warm at that time of year since 1901. This marked the third heat wave of 2019 in our southern neighbors. This last happened 72 years ago. A heat wave was recorded regionally in the Netherlands, including in North Brabant and Limburg.

Growth is leveling off
The Belgian figures from the third sampling of this season show that growth is leveling off. This means that the crops are at the bottom of the multi-year average. The average yield figure for Fontane in week 35 is 40 tons per hectare (size 35 millimeters upwards). The 4-year average is 42 tons per hectare.

For the 17 Bintje plots that were also sampled, the average is 35 tons per hectare compared to a 5-year average of 40 tons per hectare.

Very little regrowth
Compared to the previous sampling, the Fontane plots have grown by 2.700 kilos. That amounts to less than 200 kilos per day and clearly confirms that many crops are worn out due to a lack of moisture. The precipitation that fell in August was not sufficient for growth, especially in Wallonia.

At Bintje the growth is 360 kilos per hectare per day. It is very remarkable that the Bintjes are growing faster. Yet Bintje's growth curve is clearly below the average line, but it is not disastrous.

Fine potatoes
Heterogeneity remains a fact. Both between the plots and between the regions of Wallonia and Flanders. The difference is 10 tons at Fontane. The underwater weight (393 grams to 415 grams) shows that the potatoes in the French-speaking part are probably less mature than in Flanders. This can be explained because planting took place there on average 1 week earlier.

The Flemish parties are also coarser: almost 80% in the size 50 millimeters upwards. Approximately 66% has not (yet) achieved the desired size sorting, including all Bintje plots in Wallonia. Only 44% of the tubers are larger than 50 millimeters.

Crops die quickly
In Belgium too, the plot differences are sometimes large. For Bintje the yield spread is 24 tons per hectare and for Fontane it is 23 tons. There are several Bintje plots that remain below 30 tons. Another 6 are between 30 and 35 tons. The foliage at Bintje is now on average half dead. The heat probably accelerated this, Fiwap writes. At Fontane this is 40% dead foliage, compared to 22% about 2 weeks earlier. Throughgrowth is found in Bintje, but spraying with MH (Fazor) has stopped development.

Aviko figures show growth
De trial harvesting figures of Aviko Potato over week 35 still shows an upward trend. However, the underwater weight is decreasing slightly and is now at the lowest level in 6 years, just below 370. The gross yield per hectare is 56 tons per hectare. Only in 2017 and 2014 was it higher. If we follow the graph further, the crops should show growth for another 2 weeks and then level off. The percentage of 50 millimeters upwards is average and is 80%.