Growing season of loofah and key points of common pest and disease control techniques

Loofah is a widely cultivated vegetable; once cooked it tastes delicious, with soft and tender flesh, and it has cooling, diuretic and detoxifying effects. After loofah matures it becomes a loofah sponge, which can be used to wash pots, pans, bowls and dishes, and is very handy. So what season is loofah a vegetable of? What are the key points of common pest and disease control techniques?

I. What season is loofah a vegetable of?

Loofah is a vegetable of the two seasons of summer and autumn. Generally it is sown in winter and spring, and after summer arrives it will successively bloom and bear fruit. It can be grown at home; you need to prepare a loose and fertile growing medium for it, the temperature needs to be controlled at around 25°C, it needs sufficient light exposure, and appropriate fertilization, etc.

II. What are the key points of common pest and disease control techniques for loofah?

1. Loofah gummy stem blight

Loofah gummy stem blight mainly damages the stems and vines, and can also harm the leaves and fruit. The lesions on the stems and vines are oval or spindle-shaped, grayish brown, and sometimes the affected part exudes an amber-colored gelatinous substance, ultimately causing the stems and vines to die. When the leaves are affected, the leaf edges are semicircular or “V”-shaped, brown or dark brown, slightly with concentric rings, and the lesions often crack. The fruit lesions are nearly round or irregular, with brown edges and a grayish white center, and the flesh beneath the lesions is mostly black and dry-rotted.

2. Loofah downy mildew

It mainly harms the leaves. The diseased leaves first show irregular pale yellow to bright yellow lesions, which then expand into angular yellowish-brown lesions; when humid, a purplish-black mold layer appears on the back of the lesions; in the later stage the lesions join into patches, the leaves die, and yields are severely reduced. The pathogen of loofah downy mildew and the pathogen of cucumber downy mildew belong to the same kind of pathogen, called the fungus Pseudoperonospora cubensis, and the pathogen overwinters on diseased plant residues. Low temperature and rainy weather, high air humidity, large day-night temperature differences, and poor field drainage all favor the onset of the disease. In the field, the pathogen is spread by wind and rain. The rainy season is a period when downy mildew and powdery mildew occur frequently; using 50% imibenconazole·carbendazim wettable powder at 3000 times, or 430 g/L tebuconazole suspension concentrate at 6000 times liquid is effective for controlling downy mildew;

3. Loofah anthracnose

Loofah anthracnose is a fungal disease. The lesions are nearly round, of varying diameters, with the large ones about 2 cm. The color varies with temperature and humidity: when the temperature is high the color is dark brown, and when the temperature is low and humidity is high the color is light brown.

Control method: in the early stage of the disease, spray 75% thiophanate-methyl wettable powder at 700-800 times liquid + 75% chlorothalonil wettable powder at 700-800 times liquid, or 50% benomyl wettable powder at 1000-1500 times liquid, or 80% thiram anthracnose wettable powder at 800 times liquid, or 65% zineb wettable powder at 500 times liquid, or 50% iprodione wettable powder at 800 times liquid + 70% thiophanate-methyl wettable powder at 600 times liquid, with an interval of 7-10 days between sprays, for 4-5 consecutive treatments. You can also use 25% anthracnose-ling at 800-1000 times liquid for spraying, for 2-3 consecutive times.

4. Loofah phytophthora blight

It mainly harms the fruit, and sometimes the stems, vines and leaves are also affected. Fruit onset mostly starts from the flower end, the lesions are sunken, initially water-soaked and dark green; when humidity is high the melon quickly becomes soft and rots, and there is a white mold-like substance. In severe cases it can infect the leaves, stems and fruit strips. Stem and vine onset occurs mainly on the tender stems or internode parts, initially water-soaked, and after expansion the entire section becomes wet-rotted and dark brown. When the leaves are affected, they initially show water-soaked yellowish-brown spots; when humidity is high, white mold grows on them, and when dry they become greenish white and easily break apart. The pathogen is a fungus of the subdivision Mastigomycotina, the parasitic Phytophthora, and the pathogen can be spread on seeds and diseased plant residues by mycelium or oospores.

Control method: after the central diseased plants appear, promptly spray 72% cymoxanil-mancozeb (Kekangling) wettable powder at 600 times liquid, or 72% Kelu wettable powder at 600 times liquid, or 25% metalaxyl wettable powder at 1000 times liquid, or 18% metalaxyl-amine mancozeb wettable powder at 600 times liquid, or 70% ethylic phosphonate-mancozeb wettable powder at 500 times liquid, about once every 7 days, for 2-3 treatments depending on the condition of the disease.