Tomato Bacterial Cancer

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Bacterial cancer is one of the most devastating diseases in tomato. It is extremely rare to encounter it in the open ground - basically, this attack affects tomatoes in greenhouses, and it attacks absolutely all parts of the plants. It is especially dangerous that seemingly healthy tomato fruits can often contain infected seed inside. If you do not start the fight against bacterial cancer in time, crop losses can reach thirty percent. And the surviving harvest is unlikely to please, since its marketable and taste qualities will be far from desired

A few words about the disease

Tomato leaves attacked by bacterial cancer begin to fade gradually. Most often, one-sided wilting is observed, and it usually occurs from the bottom up. The leaves gradually turn brown and dry out, but they rarely fall off. On the cuts of the stalks affected by the ill-fated ailment, darkening of the vascular rings and yellow hollow centers can be observed. And on the fruits, symptoms sometimes appear that look like a bird's eye - spots up to three millimeters in diameter form on tomatoes. They are always dark in the center, and white along the periphery.

Infected fruits can be easily identified by the dark color of the ends of the vascular bundles - they are especially clearly visible when the cups are detached from the fruits. If the fruits are rather weakly affected, then yellow strands leading to the seed chambers can be observed on their sections. By the way, tomato fruits are affected not only from the inside, but also from the outside - this usually happens with the secondary spread of the pathogen. Seeds in fruits attacked by bacterial cancer are characterized by extremely low germination and are often underdeveloped.

As a rule, bacteria penetrate into growing crops exclusively through various mechanical damage. And high air humidity and high temperature contribute to the more active development of bacterial cancer. The most optimal temperature for its development is in the range from twenty-three to twenty-five degrees (maximum - forty-seven degrees). And if the thermometer rises to fifty degrees and above, then harmful bacteria begin to actively die.

In most cases, infected seeds act as sources of infection (it is noteworthy that seed infection can also be internal and external). Slightly less common sources can be soil, implements and post-harvest residues.

How to fight

Seeds for planting tomatoes must be taken exceptionally healthy. And before sowing, it is recommended to soak them for a couple of hours in a solution of "Fitolavina-300" (0.2%). It is also allowed to soak tomato seeds on the day of planting in a TMTD suspension. Some gardeners disinfect seeds with a 20% solution of hydrochloric acid for five to ten minutes. Sometimes formalin solution is also used for this purpose.

In some cases, the seeds are healed by fermenting the pulp of the fruit together with them. Such fermentation is carried out for three days at a temperature of twenty to twenty one degrees. During this procedure, the formation of acids that have a detrimental effect on bacteria (in particular, lactic and acetic) occurs.

Two- or three-time preventive spraying of seedlings will also serve well. Such spraying is also carried out with "Fitolavin-300" (0.2%), starting from the phase of one or three true leaves. An interval of fifteen days must be observed between treatments. Also, during the growing season, growing tomatoes are recommended to be sprayed with copper-containing fungicides.

Throughout the growing season, it is important to try to comply with a whole range of various phytosanitary measures, and plants on which symptoms of the disease can be detected should be promptly removed.

In greenhouses with greenhouses, the infected soil must be systematically replaced. If it is not possible to replace it, then it must be thoroughly disinfected in the fall: with formalin (1:50) or carbation (about 100 ml of it will be needed for three to four liters of water).