Phytophthora problems due to a wet summer

Good conditions

In recent weeks, weather conditions have created a very easy playing field for the plant disease Phytophthora. Persistent rain has led to a nationwide increase in Phytophthora cases. Especially in the southeastern Netherlands (East Brabant, northern Limburg) and Flevoland, growers are experiencing challenges in controlling this disease. The abundant rain has also led to impassable fields in some locations, complicating control efforts. Stichting Milieukeur ( SMK) reports widespread reports of Phytophthora outbreaks throughout the Netherlands.

More about the disease

The name “Phytophthora” literally means “plant destroyer. This disease is characterized by necrotic brown spots on the leaves, surrounded by a pale green ring, while the underside is covered with a whitish fungal fluff. Phytophthora spreads through rain and wind, returning the pathogen to the soil and other plants. In the soil, it moves through water, which easily carries swimming tracks.

A humidity of > 90% for two consecutive days is crucial for spore germination, along with a temperature above 10°C. In recent years, drought resulted in little damage from Phytophthora. Note, however, that humidity, especially when the potato foliage has fully developed, may be higher in the crop than measured above the crop. Quick action when limits (temperature and humidity) are exceeded is essential to prevent crop contamination.

The control strategy for Phytophthora revolves around stacking preventive measures, supplemented by curative measures when necessary.

Infection in tubers

In addition to the fact that the disease is strong in the potato plot, more and more tuber fields are suffering from problems. Although Phytophthora pressure nationwide has naturally been high for weeks, the many tuber infections in August this year are a rarity. Initially, tuber blight was reported mainly in Flevoland, but it is now showing up in more places. Both northeastern and southeastern regions have reported tuber infestations. Tuber blight occurs when spores reach the ground from the leaves. Once affected, tubers are unsalvageable. Stop sprays are effective in preventing further spread, but also present challenges.

Efficient Crop Protection and Higher Yields

The accurate disease warning system and optimal spray timing advice allow farmers to manage their crop protection more efficiently. By acting proactively and preventing crop damage, they can increase crop yields. In addition, SmartFarm minimizes the use of crop protection products, which not only provides cost savings, but also contributes to more sustainable farming practices.

Expanded standard

Due to high Phytophthora pressure, the active ingredient standard for PlanetProof consumption potatoes has been raised this year. SMK has decided to raise the standard for growers in the Netherlands and Germany. For long cultivation duration, the standard increased by 3.7 kg/ha, while for short cultivation duration there was an increase of 3.5 kg/ha. This is to prevent the loss of much of the crop and to prevent the spread to tuber crops.

All in all, this summer outlines a challenging landscape for vacationers and farmers alike. The increase in the standard is a nice support, but the available resources still need to be tactically deployed in this regard. As mentioned above, preventive action is extremely important here. SmartFarm can come to the aid of farmers in this regard. This by providing comprehensive insight into your field’s disease pressure and helping farmers pick the most efficient spray timing.

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