Harmful Symptoms and Control Methods of Luffa Powdery Mildew

Luffa powdery mildew is a disease caused by a pathogen and is very common in the process of growing luffa. This disease mainly occurs in early April and late June, when the temperature is relatively mild and the relative humidity is high. It is prone to occur in fields with poor ventilation and high planting density. Below, Qinong Web will answer for everyone the related questions about what to do when luffa gets powdery mildew.

First, we need to understand the symptoms of luffa powdery mildew, and then prescribe the right treatment according to the symptoms. This pathogen mainly harms the leaves. The stems, vines and fruits of luffa are less affected, but poor leaf development will also have a certain impact on luffa yield and quality. The specific disease symptoms are introduced below.

I. Harmful Symptoms of Luffa Powdery Mildew

In the early stage of luffa powdery mildew, small round white powdery spots appear locally on the leaves, and later gradually expand into irregular powdery small mildew spots with inconspicuous edges (that is, the pathogen's conidiophores and conidia). When the occurrence is severe, dozens of powdery mildew spots gather and connect into one patch, but they rarely cover the entire leaf, and finally cause the leaves to turn yellow. Sometimes small black spots appear on the diseased spots. Generally, affected leaves only show chlorosis or become pale yellow. Luffa stems, vines and fruits are rarely affected.

II. Control Methods for Luffa Powdery Mildew

When it comes to control methods, Qinong Web still recommends prevention first and treatment second, because everyone now likes to eat pollution-free vegetables, and spraying too much pesticide on luffa is not conducive to the sale of luffa. Below, Qinong Web will specifically introduce how to prevent and control it.

1. Seed disinfection: Before sowing, first sun the seeds in sunlight for 1-2 days to kill surface miscellaneous bacteria and improve germination vigor. Stir and soak the seeds in 50-55°C warm water for 30 minutes, then when the temperature drops to 30°C continue soaking for 8-10 hours, then place them in 1% potassium permanganate solution for disinfection for 20-30 minutes. After rinsing clean, germinate at 28-30°C for 48-72 hours, and sow when the radicle emerges.

2. Strengthen management: It is best to carry out 2-3 years of rotation with grass family crops. Apply 5000-7000 kg of decomposed farmyard manure, 20 kg of ternary compound fertilizer, 15 kg of potassium chloride, and 5 kg of urea per mu. Generally, no topdressing is applied during the vine extension period. During the fruit expansion period, apply 20 kg of potassium sulfate compound fertilizer per mu, and keep the soil moist. After rain, clean the ditches and drain water in time. Remove diseased, old and yellow leaves at the base in time, and bury them deeply or burn them in a centralized manner. Strengthen field ventilation and light transmission, and enhance plant stress resistance.

3. Spray protective film: Before the onset of luffa powdery mildew or in the early stage of onset, spray 99.1% Daisong 300-500 times solution on the leaves to form a protective film. Spray once every 5-7 days, for 2-3 consecutive sprays.

4. Chemical control: Apply pesticides at the appropriate time from late April to July. Before the disease occurs, 53.8% Keshade 2000 type 1000 times solution can be used. In the early stage of onset, 10% difenoconazole 1500 times solution, or 40% flusilazole 8000 times solution can be used. Baking soda 600 times solution can also be used for control. Start spraying when 1-2 diseased spots appear on individual leaves, spray once every 3-4 days, for 4-6 consecutive sprays. Baking soda can not only prevent disease, but also promote growth, and increase luffa yield by 10-20%. When spraying, try to use nozzles with small apertures to reduce leaf surface humidity.

The above are the control methods for luffa powdery mildew brought to you by Qinong Web. We hope they can provide some help to the majority of farmers. Properly reducing planting density during the planting process and strengthening ventilation and light can also reduce the probability of this disease.