What are the control methods for downy mildew in loofah?
Loofah, in the Pearl River Delta loofah specifically refers to the eight-cornered gourd, a plant of the Cucurbitaceae family native to India, also known as vegetable gourd, widely cultivated in East Asia. It is a climbing herbaceous plant of the Cucurbitaceae family, with a strong root system. The stem is trailing, five-ridged and green, and both main vines and side vines grow luxuriantly; the stem nodes bear branching tendrils and readily produce adventitious roots. It is distributed and cultivated both within and outside China. The fruit is a summer vegetable, and its various nutrients are relatively high among gourd foods; the saponin-type substances, loofah bitterness principle, mucilaginous substance, wood gum, citrulline, xylan and interferon and other substances it contains have certain special effects. When mature, the reticulated fibers inside are called loofah sponge, which can replace sponges for scrubbing stoves and furniture. It cannot be eaten raw, and can also be used medicinally, with effects of cooling, diuresis, promoting blood circulation, dredging meridians and detoxifying, as well as anti-allergy and beauty effects.
Loofah varieties
1. Zaoyou No. 1: The first female flower is at node 7-8, after which each node bears 1 female flower; the fruit strips are uniform and straight, the skin is emerald green, the waxy powder is thick, the commercial fruit is about 26 cm long, about 7 cm in transverse diameter, single fruit weighs about 500 g, and the general yield per mu is about 5000 kg. This variety has strong resistance to cucurbit downy mildew, phytophthora blight and powdery mildew, is tolerant to low temperature and relatively tolerant to heat.
2. Xinzaoguan 406: Extremely early maturing, tolerant to low temperature and good under weak light, excellent quality, high early yield; the first female flower is borne at node 5-6, after which 1 fruit per node; the fruit is 40-45 cm long, 5-6 cm in transverse diameter, dark green in color, with a thick white waxy powder layer, fresh in taste and slightly sweet. Suitable for protected cultivation in early spring or open-field cultivation in early spring.
3. Xingshu Meijia: Extra early maturing, the first female flower is at node 6-8, belongs to the flesh loofah type, with extremely strong continuous fruit-setting ability; the fruit is about 28 cm long, about 6 cm in diameter, single fruit weighs about 300 g, and the marketability is excellent.
4. Xingshu Zaojia: Extra early maturing, the first female flower is at about node 8, with extremely strong fruit-setting ability; the fruit is green with slight wrinkles, 32 cm long, about 6 cm in diameter, single fruit weighs about 420 g, the flower calyx remains for a long time, and the marketability is very good.
Loofah downy mildew is one of the main diseases of loofah. Recently, loofah production in many vegetable areas has been severely harmed by downy mildew, causing numerous lesions, dried melon leaves, premature plant senescence, and bent, thin and aged fruit strips, with yield and quality declining significantly. So how should loofah downy mildew be controlled?
Symptoms of loofah downy mildew:
Loofah downy mildew mainly damages leaves. At the early stage of the disease, irregular brown-green-yellow spots appear on the upper surface of the leaves, gradually expanding into polygonal yellow-brown lesions; when humidity is high, a gray-black mold layer grows on the underside of the lesions, and in the later stage the lesions merge into patches, and the entire leaf dies.
Control methods for loofah downy mildew:
To control loofah downy mildew, choose excellent disease-resistant varieties, raise strong seedlings intensively in nutrient pots, prepare the beds so that drainage is good, apply sufficient base fertilizer, pay attention to training vines and pruning, ensure ventilation and air permeability between plants, and more importantly, spray pesticides in a timely manner and use the right pesticide for the disease. Before the disease occurs and at the early stage of the disease, choose protective agents, such as 75% Dashuangning 600-800 times solution, chlorothalonil or Baikening (40% suspension concentrate) 500-700 times solution; during the disease period, spray therapeutic (and protective) agents, such as Shadushuangjing (64% wettable powder) 600-800 times solution, Shuangjin (55% wettable powder) or Shuanglu Sujing (72% wettable powder) 800-1000 times solution. Spray once every 7-10 days, and spray 3-5 times continuously depending on the condition, taking care to spray both the leaf surface and the leaf back evenly and thoroughly.