Recognizing tomato diseases: What are the causes of yellow leaves, brown spots and other deficiency symptoms?

Growing tomatoes is not particularly complicated, provided you follow the simple care rules and fight pests in a timely manner. Things get a little more complicated when the various deficiency symptoms have to be recognized. Yellow leaves, brown spots or white powdery substance on the above-ground parts of the plant: Tomato diseases have different characteristics that are sometimes difficult to explain.

What do tomato diseases look like?

It is not always easy to recognize tomato diseases. In addition to spots that appear on the stems, fruits and leaves, dried or twisted leaves can also indicate disease. In this case, it is important to act quickly because the affected fruits are often no longer edible. As a rule, the first step is to remove all diseased parts of the plant.If you have tomato plantsIf you grow it in pots on the balcony or terrace, then you should immediately move the diseased plant to another location. Fungi in particular spread quickly and can also attack neighboring plants. Tomatoes grown in a greenhouse should be planted as far apart as possible.

Tomato diseases: Brown spots on the leaves are a sign of brown rot

If after several days of rain or after a heavy watering you suddenlybrown spots on leaves, shoots and fruits, then it is most likely brown rot. The disease is caused by a fungus. Moisture on the leaves makes them more susceptible to fungal attack. The wrong location is most often the reason for the infestation. The tomatoes should be kept as sunny and protected from rain as possible. Incorrect watering, too often but too little, or watering from above also makes the plants sick. The affected fruits are inedible.

Brown spots during long periods of heat and drought can indicate fungal disease

It's not just waterlogging and damp leaves that affect tomatoessusceptible to fungal diseases. They can also weaken long periods of heat. If youbrown spotswith concentric rings on the plant leaves, then it is alternariosis. Plants in the kitchen garden that are planted close together are particularly at risk. Cut off all affected leaves as quickly as possible, then disinfect the secateurs thoroughly and dispose of the plant parts with household waste.

If tomatoes become diseased on the stem and develop yellow leaves, then it is stem rot

Another fungal disease first becomes noticeable on the stem. Dark brown to black, sunken spots appear first on the stem and then on the leaves and fruit. Then the plant gets yellow leaves. As the disease spreads, one may also notice a thin white coating on the above-ground parts of the plant. Injuries to the stem are an entry point for fungi and other diseases. Especially when the tomatoes are tied,

When the leaves curl

Curling leaves are not a sign of disease, but of improper care. Most of the time it is due to incorrect rooting and fertilization. It often happens that too many leaves are removed but the fertilizer application is not reduced. If the plant suddenly has few leaves, then it needs significantly fewer nutrients. There is an oversupply of nutrients and the leaves curl. Incidentally, over-fertilization can also occur if it rains on hot days and the soil releases more nutrients from the incorporated compost or manure.

Possible solution: Stop the fertilizer information for a short time, stop cutting the tomatoes and, if possible, water them thoroughly. This allows the nutrients to reach the deeper layers of the soil where the tomatoes cannot reach them. Repotting potted plants also helps.

Blossom end rot on tomatoes

Blossom end rot is also not a disease. The black spots on the fruits are typical of them. The good news – cause of theBlossom end rot is the soil condition(calcium deficiency) and irregular watering. In this case, it helps if you water the tomatoes more often than usual and have the soil condition examined. In addition to the results, laboratories also write down several recommendations for suitable fertilizers.

Tomatoes often suffer from diseases. Incorrect care, lack of nutrients, irregular fertilization and too dense planting in the flower bed or planter can promote the spread of fungi, bacteria and viruses. Possible measures for prevention and control include: Planting the tomatoes at least 60 cm apart, regularly removing diseased shoots and leaves and investing in disease-resistant varieties. Also check the condition of the soil before planting and choose a suitable fertilizer. Always water the tomatoes from below and always generously. If possible, water the plants with rainwater.