Mancha Marron de Tomas – Cladosporium Yellow (Fulvia Yellow) – Blog

It is not a secret that the tomato, in particular the one cultivated in the solarium, is one of the favorite crops of farmers, thanks to their high performance, quality and possibility of capitalization in the low season, at competitive prices.

To fully benefit from these benefits, the control of diseases and parasites in the solarium must be a priority for each farmer. Therefore, an integrated protection program should be included aimed at preventing and combating pathogens. Biological, cultural, physical and chemical measurements. The first step to apply this program is the early identification of diseases and parasites present in the harvest.

The capricious climate of recent times, with abundant rainfall that alternates with high temperatures, has created favorable conditions for the appearance of various diseases in the solarium.

One of the most harmful diseases whose incidence has increased in recent years in the case of the cultivation of tomato in protected areas Brown stain in the tomatoes.

The pathogen

The brown stain in the tomatoes is caused by the mushroom. Yellow cladosporio And it is a specific disease of the tomatoes grown in protected areas.

It may also appear in the cultivation of tomato in the open field, but the winds and intense rains prevent the development of the mushroom.

The transmission of the disease from one year to the other occurs through the resistant mycelium of the affected organs, through the spores of the mushroom, which are found in the dust deposited on the elements of the sun system and on the ground.

The transmission of the disease during the vegetative period occurs when the mushroom finds the optimal conditions for its development, its spores are transported by air currents, by insects (white Musconte in the greenhouses), by the tools and equipment of the workers, etc. .

Conditions that favor the appearance of the disease.

• • Transmission of the disease from one year to the next

• • The lack of ventilation in the solarium, combined with the presence of drops of water on the leaves.

• • High humidity of the relative air, greater than 90-95 %, related to a temperature of 22-24 ℃

Symptoms of the disease.

The first symptoms of the disease appear on the face of the developed leaves, in the form of discolored yellow points, which expand over time. Next to these points, on the lower side of the leaves, the first day after the infection appears to be a white hands (conidi and conidifori of the mushroom), which then becomes brown, finally acquiring a dark brown color. If it evolves, the points are joined, the fabrics concerned are necrosons and the interested leaves are dried, weakening the plants. The former leave dry after the attack are those of the base of the plants.

Rarely, in the case of a stronger attack, it can also appear in stems, petioles, flowers and fruits.

Small brown spots appear on the stems and extend around them, making the stem rot, break and bend.

The flowers affected by the infection are destroyed.

The most affected fruits are those of the upper level: the discolored points appear around the peduncle that become brown, penetrate the fruit pulp and therefore begin to expand.

How do we prevail?

• • Choose hybrids of brown stain resistant tomato.

• • Destroy the remains of infected plants, disinfect the production space.

• • Use a drop irrigation system to avoid logging.

• • Use the crop coverage technology to control relative humidity of less than 90 %.

• • Ventilate the lot correctly

• • Implement cultural practices that maximize the circulation of the air around the plants, guaranteeing adequate distances of the system and deflective the lower parts of the tomatoes.

How do we fight?

Through preventive and healing treatments with fungicides in approved doses and respect for pause times to the harvest: Ditano M-45, Bravo 500sc, Topsin WDG, captain 80 WDG.

Clean each plant well, paying particular attention to the lower part of the leaves.

Conclusions

The presence of this disease in tomato plants causes a large loss of quantity and quality of the plant due to the cessation of the growth of fruits and poor growth. Therefore, it is important to take preventive and preventive measures with the frequency necessary to protect tomato plants. Have you seen this disease in tomato plants? In this case, how do you proceed?