Keep in mind that in the greenhouse the temperature is always higher than on the street. Therefore, if the air is warmed more than +28°C, the leaves to prevent excess evaporation, curl into tubes. This can be seen in strong heat even in the beds in the open ground.
Important feature: at night, the foliage needs to straighten up – after all this time the heat subsides.
What to do: greenhouses pritamnagar, improve air circulation. Outdoors, the plants are sprayed stimulants, or foliar fertilizers.
The lack of moisture
In the heat with lack of moisture the plants again limit evaporation, twisting the sheets into a tube. At this time, it is recommended to water them once a week. If sandy soil, then every three to four days. In the greenhouse everything is different: at +16...+20°C and watered once every 7-10 days; at +20...+25°C – once every five days; at +25...+30°C in the day, but in very small doses; above +30°C – very small daily doses (called refreshing glaze). If Your tomato leaves curl, the first thing you need to do is to ventilate the greenhouse and water the plants.
Lack of fertilizers
If no watering or ventilation does not help – means, the reason in the other. Often in lack of food. From hunger they curl in different ways, depending on what element is lacking.
Nitrogen. Is on the skinny soils and serious violations in care. The leaves are turning yellow and shrinking, then spun down and dry. Urgently need nitrogen fertilizers or mullein, or the herb infusion.
Phosphorus. The leaves curl up and become purple. To neutralize 1 Cup of superphosphate pour a liter of boiling water and insist day. Then diluted in 20 liters of water and watered the roots. You can make it in dry or use ash, but then the result will be visible 10 days later.
Potassium. The leaves are rolled up into a tube, the edges of formed a brown border. To neutralize the lack of necessary chlorine-free fertilizers. The best remedy is potassium nitrate because it contains nitrogen. A great solution is the extract of the ash (100 g pour boiling water and insist day).
Copper. Its deficiency is rare as we copper-containing drugs protect tomatoes from disease. But if the leaf edges curl up and they appear yellow indistinct spots, spray plants with copper sulfate.
Calcium. The leaves curl up, the fruit appears apical rot. Plants urgently need to spray foliar fertilizer with calcium.
Translated by service "Yandex.Translation"