Current weather conditions in Brandenburg, Germany (August 2025) and their impact on mycotoxins in grain
Extreme weather conditions characterized the year 2025 in Brandenburg. An unusually long spring drought was followed by torrential rain in July. According to official DWD data, the period from February to April 2025 was the driest in Germany since comparable records began in 1931 [1]. But then came the turnaround: in July, the weather “pulsated” in the opposite direction. Brandenburg was one of the wettest regions in Germany. A total of around 135 liters per square meter fell that month—one of the top 10 in recorded history and almost three times the climate average [2]. This helped extinguish forest fires in early July; at the same time, the average temperature was just under 19°C above the reference value [1]. In other words, it was both very wet and warm – conditions that bring new concerns for farmers. The harvest should have been completed by the beginning of August, but the grain is still standing in many fields. The reason: the grain must be dry to be harvested, but it is too wet and is starting to mold [3]. What does this humid, warm weather mean for harvest quality, especially in terms of dangerous mycotoxins in grain?
Humid, warm weather promotes mycotoxin formation
Mycotoxins are mold toxins that are mainly produced by Fusarium fungi. Two toxins are considered particularly problematic in grain: deoxynivalenol (DON) and zearalenone (ZEN). They are produced when fungi attack ears or cobs—a risk that is closely linked to weather conditions. Warm, humid weather around flowering time provides optimal conditions for Fusarium: temperatures above ~18°C and regular precipitation (>5 mm) with persistent leaf wetness are considered “dream weather” for fungal infection [4].
Even with grain that has already been harvested, special caution is required after such a summer. Heavy rain and high humidity shortly before or during harvest can lead to secondary infections – for example, by Alternaria species or renewed Fusarium spores.
Risks to feed and food quality
If harvest batches exceed the permitted mycotoxin limits, they may no longer be marketed as food.
In the best case, they can still be used as animal feed; in the worst case, they must be disposed of at a cost. Even moderate exceedances can be expensive for farmers, for example through price reductions or complete rejection of the batch at the time of purchase.
Contaminated feed poses a serious problem for animal husbandry. Pigs are particularly sensitive to DON (also known as “vomitoxin”) – it leads to loss of appetite, vomiting, and reduced growth. Zearalenone in feed has a hormonal effect and can cause fertility problems and miscarriages in sows. Cattle are somewhat more resistant due to their rumen, but here too, high toxin levels damage health and performance, for example through immunosuppression or cell damage to the liver and intestines. Even in straw bedding, Fusarium toxins can cause problems – curious cattle eat it and thus ingest toxins unnoticed.
From a consumer perspective, cereal products are particularly relevant: bread, pasta, breakfast cereals, etc. Although strict maximum levels apply in the retail sector, certain “traces” can be found in almost every type of flour – one reason why authorities are keeping a close eye on the issue. Germany has played a key role in developing the EU limits and has recently tightened them further: since July 1, 2024, new maximum levels for DON in cereals apply, e.g., only
1,000 µg/kg in wheat, rye, barley, and spelt (previously 1,250 µg). For corn, the limit is now 1,500 µg/kg, and for the first time, fixed limits have also been introduced for T-2/HT-2 toxins. These regulations reflect the realization that even lower amounts of toxins than previously thought can be problematic. For farmers, however, they pose an additional challenge: crop quality must be monitored and ensured even more closely in order to meet the stricter standards.
Long-term climate developments and new challenges
The extreme weather events of 2025 are not isolated incidents, but part of a worrying trend. Climatologists confirm a significant change in Germany: since 1881, the average annual temperature in this country has already risen by more than 1.5°C. The past eight years have included the five warmest years since measurements began – heat waves and record droughts are becoming more frequent. At the same time, the DWD has observed a tendency toward an increase in heavy precipitation in many regions, even though this naturally varies greatly [5].
Climate models from the Intergovernmental Panel on Climate Change (IPCC) predict further exacerbations for Central Europe: on average, summers will be drier, but individual rainfall events will be more intense; milder winters could favor new pests, while late frosts will become less frequent [5]. The bottom line is that weather variability is increasing, making planning more difficult for farmers. Extreme years such as 2025 could therefore become the new normal rather than the exception. The mycotoxin problem is likely to increase in a warmer, more humid climate – on the other hand, very dry years can sometimes reduce the risk of mycotoxins.
The example of 2025 shows that quality assurance in agriculture is facing new climate-related risks. Mycotoxins in grain form a link between weather and consumer safety: they demonstrate how climate change can directly affect food quality.
SAFIA enables the early detection of mycotoxin contamination in grain. Timely analysis helps to prevent quality losses and avert economic damage. Our analytical solutions support laboratories, agricultural businesses, and companies in the feed and food industry in reliably ensuring product safety. Would you like to know how SAFIA can specifically support you in this regard? Then get in touch with us!
[2] https://www.dwd.de/DE/presse/pressemitteilungen/DE/2025/20250730_deutschlandwetter_juli_news.html
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