Some vegetable growers, first encountering yellow spots on the tomato leaves in the greenhouse are perplexed - as so, because inside there is a microclimate, and bushes are protected from the negative influence of the atmosphere.
The causes of the appearance of yellow spots on the leaves of a tomato
In general, this problem can arise in three cases:
- drops of dew falling from the roof;
- fungal disease;
- excess fertilizer.
To understand what caused stains on the leaves of a tomato in a greenhouse, you should carefully inspect the lesions. If the cause was the drops of dew arising from the difference in temperature outside and inside the greenhouse, then they will not have a big impact on the crop.
Such spots become white with time, but the leaf does not shrink and continues to grow. To help tomatoes, it is necessary to open the greenhouse early in the morning, thus, removing a large concentration of moisture.
A more serious problem, from which the whole crop may die, is the appearance of a fungal disease of cladospotriosis . It can arise because of the thickening of plantations, when there is no way to fully ventilate the greenhouse.
Another factor causing such fungal damage is very hot weather and high humidity inside the greenhouse. If you look closely at the affected leaves, you can see that they are covered with yellow spots on the top, and the spots on the back of the sheet are gray-brown. Over time, the affected plant is completely affected and dries up.
Another reason why the tomato leaves appear yellow spots - too frequent fertilizing . In particular, this refers to the excess of cow manure in the soil and in the form of irrigation. If you know that the spot was most likely due to such excess, then this season there is no longer any need to fertilize plants.
If you do not know what to do, when yellow leaves appear on tomato leaves, the best option is to treat plants and the walls of the greenhouse with a solution of copper sulfate.