What medicine is used for cucumber leaves with yellow spots?

Iron deficiency, young leaves and old leaves appear yellowing at the same time, the mesophyll of young leaves turns yellow, the leaf veins are green, forming a network of yellow leaves, generally watering ferrous sulfate, but the concentration should not be too large, can be applied in stages, to avoid burning roots. Calcium deficiency, young leaves turn yellow and curl, can be applied to crushed egg shells or imported chelated calcium and magnesium fertilizer to reduce the harm.

Plants are deficient in magnesium, the leaves turn green and yellow, and finally dry up and die, and calcium, magnesium, phosphorus, and magnesium sulfate fertilizers are applied in time. Lack of sulfur, yellowing of leaf veins, timely application of ammonium sulfate, etc., to promote the leaves to turn green. In strong alkaline soils, yellowing of leaves will also occur, and acidic fertilizers such as rice washing water and ferrous sulfate can be applied to change the soil environment.

Overwatering or stagnant water, the young leaves of the plant turn yellow, excessive drought, the old leaves begin to turn yellow, gradually aggravated from the bottom to the top, and even the whole plant dies.

This is anthracnose of cucumbers. Prevention and control methods: first knock off the diseased old leaves, and then use pesticides to prevent and control.

It can be sprayed with chlorothalonil fumigant, chlorothalonil dust, clomycoline dust, anthrax Fumei wettable powder, mancozeb wettable powder, antimycocin, methyl tobuzin wettable powder, Shigao water-dispersible granules and other agents for spraying, which need to be applied in strict accordance with the appropriate concentration.

Hello! Yellow spots on cucumber leaves may be downy mildew or bacterial keratosis, which has a white frosty mold layer on the back of the leaves and is water-stained. Downy mildew can be treated with methacrylene, and bacterial keratosis can be treated with chunleimycin, zhongshengmycin, etc.

Cucumber leaf macular disease is treated with methoxyacrylate fungicides this drug.

Cucumber seedling leaves appear yellow spots, may be infected with cucumber colespora leaf spot disease, can be used methoxyacrylate fungicides, such as 25 amisidad (azoxystrobin) suspension 1500 times, the front and back of the leaves should be sprayed. It may also be infected with cucumber downy mildew, which can be sprayed with 80% mancozeb wettable powder, 75% chlorothalonil wettable powder, and 80% Dasheng wettable powder, and it is recommended to use alternately to avoid resistance.

When the cucumber is infected with colespora leaf spot, there will be small yellow-brown spots on the leaves at the beginning of the disease, and with the aggravation of the disease, the lesions will continue to expand, the spots are nearly round and irregularly shaped, and the diseased part on the back of the leaf is slightly raised, and the color is yellowish-white. After the occurrence of timely spraying, mainly spraying the middle and lower leaves of the plant, methoxyacrylate fungicides can be used, such as 25 amisida (azoxystrobin) suspension 1500 times liquid, spraying the front and back of the leaves to spray, and to use the drug 3-4 times in a row.

What medicine to use for yellow spots on cucumber leaves.

Answers. 1.The yellow spots on cucumber leaves are likely to be infected with downy mildew, which can seriously harm growth and affect fruit.

2.After discovery, the diseased leaves should be cleaned up in time, and the agent should be sprayed, mainly with water.

3.When spraying, spray evenly.

4.In addition, management should be strengthened in the later stage, to ensure good ventilation, timely temperature control, and provide a suitable temperature.

5.Control the amount of watering and do not have too much humidity.

The appearance of macula on the leaf surface of cucumber is divided into two types: agricultural control and chemical control.

1. Agricultural prevention and control.

Preference is given to disease-resistant varieties; Reasonable fertilization, drip irrigation and dark irrigation technology under film are used in protected areas; After 9 o'clock, the indoor temperature rises and accelerates, and the vent is closed at this time, so that the indoor temperature in the shed is quickly raised to 34, and the indoor temperature is maintained at 33-34, so as to reduce the indoor air humidity at high temperature and inhibit the occurrence of the disease; After harvesting, the remains of diseased plants are completely removed and taken out of the field for deep burial.

2. Chemical control.

At the early stage of the disease, 25% pyrazoxystrobin emulsifiable concentrate 2500 times, 50% enoylmorpholine wettable powder 1500 times, Pulik water cherry blossom amolator 800 times or 72% frosturea manganese-zinc wettable powder 800 times liquid spray control, once every 5-7 days, 3 times in a row. When applying pesticides, please wear protective clothing, and the application method refers to the amount of agent, application time and safety interval indicated on the product label.

Precautions for cucumber planting

Cucumbers like warmth, not tolerant to cold, the appropriate temperature for growth is 10 32, cucumber high temperature 35 poor photosynthesis, 45 high temperature obstacles, and the temperature is too high will also have an impact on the taste of ordinary varieties of cucumbers, some vegetable friends grow cucumbers bitter, there is a bridge mill may be caused by too high temperature.

When the cucumber is flowering, you can use some potassium dihydrogen phosphate as foliar fertilizer to spray the foliage, as a fertilizer to protect flowers and fruits, and after fruiting, wait for the fruit to grow to the size of a fist for root topdressing, water-soluble fertilizer or compound fertilizer can be used.

1. Reason: cucumber downy mildew, commonly known as "running horse" and "dry leaves", can be damaged by adult plants at the seedling stage, and the main damage is to carry leaves and stems, and the tendrils and flower stalks are less damaged. Downy mildew occurs mainly on leaves.

At the seedling stage, the cotyledons initially appear greenish spots, gradually appear yellow irregular spots, and the back of the cotyledons produces gray-black mold layer when wet, and with the development of the disease, the leaves quickly turn yellow and dry up.

Second, prevention and control measures:

1. Properly control watering in the early stage of the disease, pay attention to enhancing ventilation and reducing air humidity in protected land cultivation.

2. Cultivate disease-free and strong seedlings, increase the application of basal fertilizer, and pay attention to the reasonable combination of nitrogen, phosphorus and potassium fertilizer.

3. Completely remove the fallen leaves of diseased plants after harvesting.

In short, to prevent and control cucumber downy mildew, we must conscientiously implement the plant protection policy of "prevention first, comprehensive prevention and control", and focus on ecological defense and chemical prevention and control on the basis of comprehensively doing a good job in the comprehensive prevention and control of pollution-free and pollution-free pests and diseases in energy-saving greenhouse vegetable cultivation.