Disease control in baby cabbage starts with field management and targeted spraying

Baby cabbage is a small type of heading cabbage with a short growing period and tender leaves, and it is prone to infection by a variety of diseases in plots with high temperature and high humidity or continuous cropping. Common diseases include downy mildew, soft rot, viral disease and black spot, and some plots also develop physiological problems such as tipburn. Doing a good job of disease control is a key step in safeguarding the yield and market quality of baby cabbage.

Identifying symptoms is the first step in control. Downy mildew mostly starts from the lower leaves, with pale yellow patches appearing on the leaf surface, and a white mould layer visible on the underside of the leaves when humidity is high; soft rot often occurs during the heading stage or after several consecutive cloudy and rainy days, with the base of the head rotting and giving off an off-odour; viral disease shows as wrinkled, mosaic-patterned leaves and stunted plants, and is mainly spread by aphids. After abnormalities are found, the type should first be identified, and then targeted measures should be taken.

Agricultural measures are the foundation of control. Before planting, it is advisable to rotate with non-cruciferous crops, choose varieties with better disease resistance, and disinfect the seeds. The field should be kept well drained, and planting density should be reasonable to favour ventilation and light penetration; avoid excessive application of nitrogen fertiliser, and suitably combine phosphorus and potassium fertilisers with medium and trace elements. After rain, drain standing water promptly, and pull out diseased plants as early as possible and carry them out of the field for disposal to reduce the spread of pathogens.

Chemical control should be carried out in the early stages of disease onset, choosing the right fungicide or insecticide registered for use on cabbage-type crops, taking care to rotate chemicals to delay the development of resistance, and strictly observing the pre-harvest interval. At the same time, insect-proof nets, yellow sticky boards and other means can be combined to control aphids and other virus-transmitting vectors. Only by adhering to the approach of prevention first and integrated control can the losses caused by disease be effectively reduced.