When red or brown spots form on dragon fruit stems, the stem turns yellow. The disease is caused by a fungus called Botryosphaeria dothidea, which produces red or brown lesions on the stems. Sometimes these look like bull's-eye spots, and sometimes several spots appear together.

The disease starts with yellowing on an infected branch and spreads upwards. It is spread by pruning shears and other tools. Most disease spreads through unhygienic gardens, especially dirty equipment.

It is important to disinfect tools between uses so the disease does not spread. Tools can be disinfected with alcohol, hydrogen peroxide or a very mild solution of bleaching powder in water.

Some diseases spread through contact between an infected plant and an uninfected one, so leave some space between plantings. To treat this fungal disease, spraying a copper fungicide such as Blitox 50 at 2 g per litre of water can reduce its severity.

Source: Jagonews24. First published in Bengali on The Agro News.