Water soaked spots turning brown with yellow halos on my chilli and tomato leaves

Small water soaked spots that turn brown to black with yellow halos, raised and scabby on chilli, spreading fast after rain and overhead watering, are bacterial leaf spot, caused by Xanthomonas. The yellow halo and the spread by water splash distinguish it from fungal spots. Bacteria are hard to control once established, so prevention is key. Use clean treated seed since the bacteria are seed borne, avoid overhead irrigation and working in the field when leaves are wet, and improve airflow and spacing. Remove and destroy badly infected leaves and old debris. Copper based sprays, sometimes combined with mancozeb, give protection if started early before it spreads, but they cannot cure heavy infection. Rotate away from chilli, tomato and capsicum for a couple of seasons in repeatedly affected fields. Since both crops are eaten fresh, follow the label and waiting period for copper sprays, and confirm with your KVK before treating.