The role of rubber rollers in the basic management of compact spinning production
Pyrimethanil is a highly effective fungicide against gray mold, which has led to its widespread use in agriculture. However, improper application can lead to phytotoxicity, which may damage crops and reduce yield. To help farmers avoid these issues, the **Chinese Pesticide Network** has compiled some important usage precautions for pyrimethanil.
As an anilinopyrimidine fungicide, pyrimethanil exhibits strong systemic activity, allowing it to quickly penetrate plant tissues and reach areas such as flowers and young fruits that are difficult to treat with other products. This makes it particularly effective for controlling gray mold. Additionally, its efficacy is not significantly affected by temperature, meaning it remains effective even when applied during cooler weather.
**I. Phytotoxicity on Potatoes and Eggplants**
Although pyrimethanil is effective, improper use can cause phytotoxicity, especially on eggplants. Symptoms include dark brown spots on leaves, irregular yellowing, or leaf curling. Many farmers mistake these symptoms for "spotted wilt disease," leading to repeated applications that worsen the problem. It's crucial to differentiate between pyrimethanil-induced phytotoxicity and actual disease symptoms.
Similarly, beans (such as canola, cowpea, and others) may suffer from severe yellowing, browning, and leaf drop when exposed to high concentrations of pyrimethanil. While this compound isn’t entirely unsuitable for these crops, it must be used carefully. The recommended active ingredient concentration should not exceed 6g per mu (approximately 0.15 acres). For example, if using a 40% pyrimethanil suspension with 15% active ingredient, no more than 40g per acre should be applied to eggplants and beans.
**II. Phytotoxicity on Cucumbers**
Cucumbers are particularly sensitive to pyrimethanil. Application may result in chlorotic yellow spots on leaves, and under high humidity and temperature conditions, young fruits and flowers may show burning or whitening. Leaves often develop irregular yellow patches and white spots. Due to this sensitivity, it is generally advisable to avoid using pyrimethanil on cucumbers unless absolutely necessary.
After application, lettuce and oilseed rape may also show light yellow halos around the leaves, which can be mistaken for nutrient deficiencies. Therefore, careful consideration and testing are essential before applying this product.
**III. Phytotoxicity on Tomatoes**
Tomatoes are one of the crops where pyrimethanil is most commonly used to control gray mold. However, the level of safety varies depending on the variety and environmental conditions. Some tomato varieties, like large red cherry tomatoes, are safe to apply at 26°C in early spring. But under high temperature and humidity conditions, some plants may show marginal yellowing, which is often misdiagnosed as magnesium deficiency. Farmers should exercise caution when using pyrimethanil in such environments.
**IV. Phytotoxicity on Melons**
When used correctly, pyrimethanil is relatively safe for melons. A dilution ratio of 700–1000 times is typically considered safe and effective for preventing diseases. Proper application ensures good protection without causing significant harm to the crop.
In summary, while pyrimethanil is a powerful tool in managing gray mold, its use requires careful attention to concentration, timing, and crop sensitivity. Following these guidelines will help maximize its benefits while minimizing the risk of phytotoxicity. Always read and follow the manufacturer’s instructions and consult local agricultural experts if unsure.
Chuzhou Jincheng Metalwork Co.,Ltd , https://www.jinchengscaffold.com