How did the potatoes survive the heat?

On 8 and 9 August, the Belgian potato organizations – including PCA en fiwap – in Flanders Wallonia again sampled 33 plots of Fontane. The planting date in particular ensures that there are significant differences between them. The early potted plots achieve the highest yields, but the late plots are the greenest. The most quality problems can also be found there, especially through washing.

Yield drops below average
On average, the gross yield is 35,4 tons per hectare, with a wide spread between 18 and 49 tons. This means that since the previous measurement, 340 kilograms have been added per day. This is not bad considering the dry weather, although it should be noted that these samples were taken before the current heat wave. Five Flemish plots are irrigated. Due to this under-growth, the yield falls below the multi-year average of 37 tons per hectare. The coarseness has also increased by 22 tons per hectare 50 millimeters or more. That too is below average.

The underwater weights are extreme in Belgium with an average of 440 grams. That's unique. The maximum is now above 500 grams with a lower limit of 400 grams. The foliage has matured on average by 30%, again with a good spread between 0% and 70%. On average, the potatoes in Wallonia are slightly greener than in Flanders, where it is also drier. Baking quality is excellent, but quality issues have also been observed, especially on a very late planted plot, where overwash is a problem. This is sporadically visible on the other plots.

Challenger lacks size
The Belgian organizations also sampled 8 Challenger plots on 9 and 18 August. None of the plots is irrigated. The planting dates are all in the second half of April. Here the average gross yield is 34,6 tons per hectare, again with a wide spread: 19 to 45 tons. Challenger's multi-year average at PCA is 37 tons. It is striking that only 42% of the yield was 50mm or higher. This 14 tons per hectare is considerably less than the 23 tons on average. The maturation varies from 5% to 55% and the average underwater weight is 454 grams.

Fontane below average
Also potato trading company brewer in West Flanders has carried out the first trial harvesting. Their yield from Fontane is 32,5 tons net, slightly more than what PCA reports. The four-year average is 34,37 tons. The first figure for Challenger comes in at 35,2 tonnes net per hectare. The underwater weights at Bruwier are also above 400 grams and no through wax was found. The average maturity for Fontane is 53% and that for Challenger 30%. The company does not report whether fields are being irrigated.

Accelerated ripening
Growers in the Netherlands all report that the past few days have had a major impact on potato crops. Growth is still visible in the sampling, but it is below par. What is particularly worrying is the fact that the potatoes are now deteriorating rapidly and thus lack the potential to recover should significant rain fall. In the trial harvests, the yields may seem reasonable, but at the end of the growth curve, a few weeks of growth may be crossed out.

Two more warm days are expected today and tomorrow with maximum temperatures just below 30 degrees. The first shower is scheduled for Wednesday. Depending on the country and region, the reported precipitation varies between 15 and 25 millimeters. Only in Germany will it remain mostly dry. On Monday morning a small shower fell locally, but no more than 1 to 5 millimeters. Wednesday's precipitation can cause problems with washing through, especially on plots where the MH spraying has not been successful. A positive effect on growth is considered small, due to the extreme drought and the fact that no significant rain is expected after that time and temperatures will rise again.

Precipitation shortages rise
The precipitation deficit in the Netherlands has now risen to 271 millimeters and despite upcoming rain, that figure continues to rise. This brings the drought dangerously close to the situation in 2018. Especially in the southwest, southeast and east it is extremely dry, this also applies to the west coast in Belgium. The center of the country is also becoming drier. In neighboring France, people are now talking about a historic drought. On average, only 9 millimeters fell there in July. August is also expected to be extremely dry and hot. There has been a heat wave since June. Irrigation bans in the Northwest and Southeast leave farmers with little to save.

In Germany it is mainly about the extremely low water levels that are a major obstacle to shipping traffic. Of course, agriculture is also experiencing problems due to the lack of precipitation. It had not been this dry in Germany since 1881. The 2018 record has now been broken. At that time, 131mm of precipitation fell in the summer months, compared to 103mm this year.