I want to note that peronosporosis or otherwise downy mildew is widely known not only in the Kuban. Even pre-revolutionary magazines wrote about this disease, that is, it is not new. Just then, they knew little about the biology of the pathogen, its development, so it was difficult to organize protective measures. Preserving the crop of cucumbers, onions, if the disease has already begun to develop, is almost impossible. Nowadays, agronomists and gardeners are helped by modern agricultural knowledge, special preparations against peronosporosis, but they must be used skillfully, and, most importantly, on time.
Treatment of peronosporosis of cucumber
This is a fungal disease. With peronosporosis, leaves of cucumbers are affected in all phases of development. The disease is found in open and closed ground. On the leaves yellow-green angular spots are visible, which quickly increase in size. Leaves turn brown and die. The ovaries turn yellow, fall off. The development of the pathogen occurs at a temperature of 15-22ºС and often precipitation or dew.
Infection persists on dead leaves. In the soil, it can be found within five years after sowing cucumbers in this area. The infectious onset is stable and in adverse weather conditions.
In our conditions, the disease appears in the first or second decades of June. The peak of development occurs in mid-late July.
It is necessary to deal with peronosporosis not when the first signs of the disease are already visible, but long before the seeds are planted.
Soaking the seeds of cucumbers in a solution of Fitosporin or SILK before planting in the soil weakens the development of the pathogen, but does not completely remove the infection. Hardening of seeds in the refrigerator, treatment with potassium permanganate do not give positive results. Tillage - autumn, flat-cut - does not reduce the development of this pathogen.
I definitely advise you to perform the operation of heating the seeds on a heating boiler or hot battery. Seeds germinate better, develop, give higher yields.
Sometimes they complain: the variety is considered high-yielding, and in our country it is affected by the disease. Indeed, there is no way to get away from this. If you want to eat cucumbers - please, choose varieties for yourself individually. But 100% varieties and hybrids of cucumbers resistant to peronosporosis are not. There are those who, with some care, may not get sick.
To increase the resistance of ogres to peronosporosis, after the emergence of plants, they should be treated with sodium humate in combination with microelements. About an hour after treatment, the plants will be without film shelter. And then they need to be covered with cucumbers with a film or covering material. So they must be kept until the next watering. I water the cucumbers along the furrows to reduce the ingress of moisture on the leaves.
Mandatory feeding with nitrogen-phosphorus-potassium at the beginning of plant development. It is necessary to increase immunity, resistance of cucumbers to peronosporosis, and other diseases, too. Feeding doses are selected for specific conditions.
After 6-8 days, treatment with sodium humate and trace elements should be repeated.
A very good result is given by the formation of cucumber plants, or, more simply, the pinching of growth buds. Then more female flowers appear on the plants.
Fertilizing with organic fertilizers is carried out during the flowering period of cucumbers. They are fed a mullein solution at the rate of 1:20. Such top dressings are given 3-4 per vegetation.
Of the chemicals used to treat cucumbers before setting fruits, Khom in a 0.4% concentration, Ridomil + Khom (or copper chloroxide) 2: 3 is used, for some time he used ridomil.
With severe damage to the leaves of cucumbers by peronosporosis, when preventive measures are late, SILK, Khom are used. But in this case, you can only restrain the development of peronosporosis. To reduce the degree of development of the disease, to cure cucumbers, this complex of agricultural practices will not give an opportunity. Adverse weather conditions, cool nights, high humidity contribute to the development of peronosporosis - the pathogen begins to progress significantly.
All these measures to protect cucumbers from peronosporosis are costly and moral. It is unlikely that they will be able to completely save the entire crop if they are late with preventive measures. But the harvest will still be. There will undoubtedly be more than nothing to do. Even in conditions of a strong outbreak of the disease, you can get good yields of cucumbers, holding back the development of peronosporosis (downy mildew) described above.
Peronosporosis of onion, control measures
Peronosporosis onion, how to fight? This disease is found from year to year on crops of onions, which are grown in our garden. Leaves are sick, acquiring a pale color with yellowness. The leaves change shape: from flat, elongated in the longitudinal direction, they become ribbon-like, later wrinkled, often bent by an arc, the tops are tilted down. The leaves turn black due to the dirty gray coating on their surface.
Optimum conditions for the manifestation of peronosporosis: there should be drip-liquid moisture for 6 hours and an air temperature of 12-16 ° C. This disease manifests itself faster if there are sharp jumps in temperature to the lower limits within 2-3 days and its increase to higher, exceeding the specified interval.
Consider what to do to avoid onion disease with peronosporosis during planting.
Sevc is soaked in a solution of sodium humate and trace elements. You can use a solution of Fitosporin, HB-101. Be sure to dry the seeds before planting.
Now - about the agricultural technology of growing onions.
After preparing the soil, mark the planting planting taking into account the optimal nutrition area. The landing pattern is maintained at the rate of 6 cm in a row between onions and 20 cm between rows. In general, there are about 80 plants per 1 m2.
We try to regularly carry out weeding and cultivation. During the formation of onion feathers, we feed it with nitrogen-phosphorus-potash fertilizers. After top dressing, watering is required.
After watering, the first treatment of onions with fungicides is carried out. This work is carried out with a preventive purpose.
I worked with Hom in a 0.4 percent concentration. For better retention of the drug on the leaves of onions, 2 tablespoons of milk (fatty) was added to the solution. There is casein protein in milk, which contributes to better adhesion of fungicides to onion leaves. The effect of the solution with milk is much higher than the treatment with a pure drug.
During the formation of the bulb, the drug Ridomil with the addition of copper oxychloride is used. Copper chloride enhances the effect of Ridomil. After 10 days, repeat treatment with Ridomil. 15 days before harvesting, treat the onion again with Homa 0.4%.
With this treatment, you can completely protect the onion from peronosporosis. The yield of onions will be high. The costs of growing it will pay off with the resulting crop.
Gather onions with tops and put them for ripening in a heated room. Then, when the tops are dry, cut the onions and place them in a dry storage room heated by the sun's rays.
I want to recommend summer residents who exhibit peronosporosis of onions: try to observe a complex of agrotechnical techniques, I am sure that it will be possible to contain this dangerous disease.
I wish you success and high yields of cucumbers and onions.