My maize stalk has gone soft and brown at the base and plants are falling over

Plants snapping at the base after tasselling, with the lower stalk gone soft, discoloured brown inside and a bad smell, point to a stalk rot, a complex of fungi and sometimes bacteria that move in when the plant is stressed, especially with moisture stress after flowering, heavy nitrogen with low potash, or borer wounds that let the rot in. Split a few stalks lengthwise to see the rotted, shredded or discoloured pith to help confirm, and send a photo to your KVK or agri officer. There is no effective spray once the stalk is rotting, so the focus is on management and prevention: keep balanced nutrition with enough potash and avoid excess nitrogen, maintain steady moisture and good drainage to reduce stress around flowering, control stem borers in time so they do not open the door to rot, and grow tolerant hybrids. Remove and destroy badly rotted residue after harvest since the fungi survive there. If lodging has started, plan to harvest the affected area a bit early. Confirm the diagnosis and the hybrid and nutrition plan with your local KVK.