Powdery mildew of cucurbitsis a disease caused by the fungi Erysiphe cichoracearum and Sphaerotheca fuliginea, which manifests itself with a light coating on the leaves. The problem is mainly in greenhouse cucumber cultivation, although it can also occur in field cucumbers, courgettes, patisons and pumpkins. We advise on how to recognizesymptoms of powdery mildewon cucumber and other cucumber vegetables, as well as how tocombating powdery mildewand what sprays are recommended.
Powdery mildew of cucumber leaves
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Powdery mildew of cucurbits - symptoms
The symptoms of powdery mildew of cucurbitsare visible mainly on the leaves with a light, powdery coating. Over time, the raid can cover the entire surface of the leaf blade, as well as the petioles and shoots. In favorable conditions for the development of the disease, small black spots appear on the raid. They are conidia that can cause secondary infections.
This disease does not directly attack cucumber fruitsand other cucumber vegetables, but in case of intense infection it causes a reduction in yield (cucumber fruits grow more slowly and not grow to their normal size) and dieback of entire plants.
In the case of greenhouse cultivation of cucumbers, the symptoms of powdery mildew may appear at any stage of plant development, but most often they are noticed only around mid-July, when the harvest is already underway. Then the disease may worsen the quality of the crop (cucumbers grow slower) in the second half of the harvesting season. Powdery mildew appears on field cucumbersusually only at the end of the harvest period and then it has no significant impact on the quality and size of the yield.
Conditions favoring the development of powdery mildew in cucurbits
The powdery mildew of cucurbits can overwintermainly on plant debris and on weeds left over from greenhouse crops. The spores of the fungus are transported over long distances by the wind.
Interestingly,powdery mildew of cucurbits develops especially quickly in dry, sunny and warm weatherThese conditions are therefore completely different than in in the case of downy mildew of cucurbits, which is favored by high air humidity and prolonged rainfall.
Powdery mildew of cucurbits - ecological control
The primaryway to combat powdery mildew in cucurbitsis the choice for sowing modern cucumber and other cucumber vegetables that are genetically resistant to the disease.Fortunately, most of the cucumber varieties available today are so hardy.
During cultivationavoid long-term wetting of the leaves , both in greenhouse and field crops. Therefore, it is worth taking care of adequate air circulation in the vegetable beds (ensure airy places) and limiting the growth of plants so that they are not overly compacted. Greenhouses should be regularly aired.Avoid nitrogen overfertilization, because then the shoots and foliage grow too quickly, the plants overly thicken and become susceptible to mildew attack. In amateur crops on plots and in home gardens, it is recommended to fertilize cucumbers with compost before planting cucumbers in the beds, and for top dressing with diluted organic fertilizers, such as e.g. vermicompost. Thanks to this, the plants will certainly not receive excessive doses of nitrogen.
If the plants show the firstsymptoms of powdery mildew , remove parts of the plants with visible signs of infection on an ongoing basis.This will minimize the risk of the infection spreading further. After the end of cultivation and the last harvest, the beds should be thoroughly cleaned of plant residues. Remember that infected parts of plants should not be composted.
Powdery mildew of cucurbits - spraying
Dofight with powdery mildew of cucurbitsin home gardens and allotments, we should mainly use natural preparations, such as e.g. homemade horsetail decoction.
To prepare a stock of horsetail1 kg of fresh horsetail herb or 200 g of dried herb is poured over 10 liters of water, and then set aside until the next day. After about 24 hours, boil the pickle and keep it on low heat for 30 minutes. After cooling down, strain the broth so as not to clog the sprayer nozzle and dilute it with water in a ratio of 1: 4. Spraying is carried out at intervals of 2-3 weeks throughout the cultivation period.
It is worth knowing that horsetail decoction will also protect cucumbers and other pumpkin vegetables against downy mildew of cucurbits. Therefore, it is worth choosing this macerate for spraying.Instead of preparing a decoction, you can also buy a ready-made preparation of horsetail called Evasiol. A 50 ml package of this preparation is dissolved in 5 liters of water and the cucumbers are sprayed with it.
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Another recommended naturalpreparation for protecting vegetables against powdery mildewis Limocide. Preventive spraying of cucumbers with this preparation is recommended in the period from the second leaf phase to the maturity phase. The dosage is 40 ml of the preparation per 5 liters of water. Spraying can be repeated every 7-10 days, with a maximum of 6 such sprayings during the growing season. The preparation also prevents the appearance of pests, such as the greenhouse whitefly.
Scorpion 325 SC is worth recommending among chemical plant protection products. It is worth using it mainly in greenhouse cultivation of cucumberafter observing a strong infection of plants with powdery mildewThe preparation can also be used in the cultivation of zucchini, squash, patison, melons, watermelons and pumpkins. The basic dosage is about 1 ml of the preparation per 1 liter of water, but it may vary depending on the type of cultivation, so it is worth reading the label carefully.
Scorpion 325 SC is widely used against fungal diseases in the cultivation of various vegetables and other garden plants. Therefore, even if we do not observesymptoms of powdery mildew on cucumbers , the preparation will probably be useful in other crops. Cucumbers and Scorpion 325 SC will also protect against another dangerous disease, which is pumpkin scab. For this reason, we recommend that you have this remedy for cucumber diseases in your garden medicine cabinet.
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These are, of course, not all preparations that can be used againstpowdery mildew on cucumber vegetablesThe list of available preparations is quite long, but these seem to be the ones best suited to the needs of amateur crops . For more powdery mildew treatments, press the button below.
