Early blight threatens summer harvest: Tips to protect your tomatoes

Juicy and flavourful tomatoes are the essence of summer, a refreshing addition to salads and the cornerstone of many British dishes. Unfortunately, the end of the season brings an abundance of harvests and an increased risk of diseases that can undermine our efforts.

In August, tomatoes are particularly vulnerable to the attack of early blight, a cunning fungal disease that can significantly reduce crops.

Early blight attacks tomatoes

Early blight, also known as dry leaf spot, seriously threatens tomatoes. Humid conditions and large temperature fluctuations, typical for August, favour the development of the fungus Alternaria solani, the culprit behind the disease. It attacks leaves, stems, and even fruits, leaving dark, concentric spots on them. In the advanced stage, leaves turn yellow and fall off, weakening the plant and leading to premature ripening of the fruits, often deformed or damaged.

Early detection of early blight is crucial for effectively combating the disease. The characteristic dark brown spots with concentric rings on the leaves are the first warning signs. Over time, these spots merge, causing tissue death and leaf drop. Elongated brown streaks appear on stems and petioles. Fruits can also be attacked, becoming covered with dark, sunken spots that lead to rotting.

Using strong chemical agents during the harvest period is not advisable due to the risk of contaminating the fruits. Fortunately, there are natural and safe methods to combat early blight. Sprays of copper sulfate, in the proper dosages and timings, can help fight the disease. It is also worthwhile using natural plant protection products, such as garlic extract with antifungal properties or nettle extract, which strengthens plant immunity. A solution of apple cider vinegar with water is another effective way to combat the fungus.

Biological plant protection agents can be used for more advanced infection, such as preparations based on beneficial microorganisms that compete with pathogens. Fungi of the genus Trichoderma are natural opponents of Alternaria solani and can be applied to the soil or sprayed on plants. Remember that healthy and strong plants are less susceptible to diseases, so it is worth taking care of proper fertilisation, watering, and growing conditions.