downy-mildewDowny mildew

Tomato late blight (Phytophthora infestans) – identify and control

Tomato-late-blight-identify-and-crop

Tomato late blight, Phytophthora infestans was reported in Europe in 1847. It appears on tomatoes, especially in the second cycle of culture. In greenhouses and polytunnels, the crop damages can vary from 30% to the entire compromise of the crop.

Tomato-late-blight-symptoms
Tomato-late-blight-attack
Tomato-late-blight-identify-and-crop

Symptoms. Tomatoes can be infected in all growth stages, the leaves showing on the edges or towards the top spots with a damp appearance (dark green). Affected tissues wither, turn brown and the leaves curl up to the topside. In conditions of atmospheric humidity on the lower face of the leaves, near the spots appears a fuzz, not too dense, white. The peduncle of leaves, the shoots, and the attacked stems, have elongated brown spots, superficial, without whitish fuzz. The attacked inflorescences show on the leaves and at the base of the flower’s brown areas.

The significant attack is on the fruits, which can be attacked in all stages of development. The pathogen produces large brown-olive spots and quickly destroys the whole fruit. Tomatoes become hard, rough, and ripe ones have light brown spots, on the surface of which appear concentric areas. On fallen leaves where there is high humidity, the fungus forms a mycelium with many spores. In autumn crops in greenhouses (second cycle), the attack evolves rapidly, due to variations in day-night temperature, which cause condensation of water on the vegetative organs, condensation that eases infections.

Tomato late blight pathogen is Phytophthora infestans. It occurs especially in years with heavy rainfall and moderate temperatures.

Prevention and control. It is recommended to gather and destroy plant debris, seedlings to be produced from healthy seeds, avoid growing tomatoes in the vicinity of potatoes or on the same land, where potatoes were grown in previous years. Chemical treatments are applied at intervals of 6-7 days with specific fungicides.

Recommended products

Read carefully and follow the instructions on the label of each product

×

We help you
to take care of your plants

If you haven't yet found solutions in our articles or previous discussions, start a new discussion and our experts will help you.

During working hours, our experts are ready to give you an answer within 2 hours.

New discussion about

Tomato late blight (Phytophthora infestans) – identify and control
Tomato late blight (Phytophthora infestans) – identify and control

Your information:

Your name must contain a maximum of 30 characters. If you would like to pass on the details of the problem you are facing, please complete the other fields.

The maximum document size is 59 MB.

Add
It helps if you attach some Images or Clips maximumm 15 sec


Want to know more?

Our specialists participate in the discussions of the armuro community with useful information and solutions.
If you want, you can start a discussion about the problem you are facing.
Read the discussions