A Complete Guide to Preventing and Treating Flower Diseases in High-Temperature and High-Humidity Conditions

In March and April, flower production in northern China is generally still carried out inside greenhouse facilities, but at this time growers have already gradually reduced heating, so temperatures inside the facilities begin to drop while humidity remains very high, making it easy for fungal diseases such as gray mold and downy mildew to break out.

Dong Yuguang, plant protection technology manager at Syngenta, told reporters that greenhouse production in the north of potted flowers such as Phalaenopsis, Cymbidium, and Anthurium requires high-humidity conditions, making them highly susceptible to fungal diseases.

Although growers can avoid infection by cutting off flower stalks, he believes the best approach is still to ventilate in a timely manner to reduce humidity when the weather is fine, or to apply protective fungicides containing cyprodinil, such as chlorothalonil. If plants are found to have already been infected, chemical agents containing fludioxonil, such as Huiyou, should be used for control.

In addition to the above diseases that may occur, flower production in the south, because of high temperatures and high humidity, makes flower seedlings prone to leggy growth, and stems are often affected by some soil-borne diseases, such as damping-off and Rhizoctonia rot.

To prevent these diseases, one can directly water with a solution containing fungicide at the first watering, or mix the substrate or soil with fungicide when sowing.