Most of summer residents at least once faced yellowing of cucumber leaves, and in certain cases spots on lianas become the real scourge of gardeners. The reasons of damage of beds there can be set is the wrong care for vegetable culture, various diseases, invasion of wreckers. Whatever has caused emergence of yellow spots on leaves of cucumbers, the summer resident cannot let matters drift, otherwise considerable part of harvest can die.
Root decay
Frequent rotting of roots of liana becomes the reason that leaves at cucumbers turn yellow. Signs of they are cracks in the bottom of stalk and its premature withering. The wrong watering can be the cause of trouble: small doses, but too frequent. Water remains on surface, roots begin to move top and become vulnerable. Weeding, earthing up, ultra-violet radiation can damage them.
Abundant, but very rare watering also does not bring benefit to garden culture as roots begin to rot because of excess of water. To optimum water cucumbers 2 times a week (about 25 l of liquid on one plant). It is necessary to consider whether the earth is saturated with moisture already in addition not to fill in bed. Rotting of roots can arise if water for watering was too cold and also at unexpected frosts.
To reduce risk of root decay, you should not plant seedling on the former bed with melon cultures. It is impossible to hill cucumber stalks also too highly. If roots nevertheless have begun to rot and leaves have turned yellow, sick plants need to be dug out and destroyed, to process the others copper oxychloride (40 g on ten-liter bucket of water). Solution temperature surely has to be room temperature.
Always carefully weed all weeds on garden beds as on them many wreckers of vegetable cultures winter.
Bacteriosis of cucumbers
Disease of cucumbers of bacteriosis – widespread problem. The disease is promoted by high humidity of the earth and air, and these are indispensable satellites of regular waterings. Bacteria can strike seedling, cotyledons, fruits which rot before maturing. Spots between veins of leaves at this disease angular, brown or dark green color. During rain and after dew loss you will easily make to the cucumbers the diagnosis "bacteriosis": spots on leaves become oily, drops of muddy slime appear. Bacteriosis of cucumbers treat bactericidal medicines, such as Previkur (20 ml on ten-liter bucket of water), "Kvadris 250 SC" (6 ml on 5 l of water) or Etafol (20 g on bucket). In the fall, after collecting fruits, beds are deeply plowed up – even if in holes there were sick leaves, in the winter of bacterium will die in the earth. Always it is necessary to observe competent crop rotation completely to purify soil. Instead of cucumbers it is the best of all to plant oats, peas or beans and to return favourite vegetables on the former place not earlier, than in 4 years.
Defeat by insects
Leaves of cucumbers can turn yellow if culture has been struck by insects. Most often lianas are chosen by the melon plant louse adoring damp and warm weather. As a rule, at its emergence on bed leaves turn not just yellow and are twisted, but also ovaries and inflorescences are damaged. Good results at fight against this garden wrecker are yielded by processing of plants solution of laundry soap (300 g on ten-liter bucket of soft water). If means does not help, it is necessary to spray lianas with insecticidal medicines, such as "Carbophos", Trikhlorol, "Phosphamide". Operate according to the instruction on packing.
If you had to spray vegetable bed with chemicals, all cucumbers which were on liana during processing should be thrown out. The following tied fruits can already be eaten.
There are many garden wreckers causing damage of leaves in cucumbers, lag of growth of liana and decrease in productivity. Among the most widespread - worm-shaped nematode, web tick, stem sawfly. At the first signs of attack of insects the plant can try to be saved, having processed chemicals. But if the liana has begun to wither suddenly quickly, dig out and burn not only sick plant, but also soil from hole. Even if you so have not found out the reason of yellowing of cucumber leaves, follow the simple rule: the infection needs to be deleted in due time that the disease has not extended to all bed.