Foot rot

is a plant that suddenly wilts and yellows from the top even though the soil is wet — the leaves droop, go pale, then dry and die back, as if the plant is thirsty in a flood.

and you'll find the real sign: a dark brown to black, sunken, water-soaked patch on the stem at the collar (where stem meets soil). On tomato and bean it looks like a soft, wet rot; the outer skin cracks and peels and the tissue underneath is mushy and discoloured.

the collar oozes a sticky, gummy sap — this gumming dries into brown blobs on the bark, and the bark splits, dies and peels away from the wood.

— the dark rot spreads sideways until it makes a complete ring right around the stem base. Once the ring closes, everything above it is cut off and dies. Scratch the bark with your thumbnail: healthy tissue is green and firm, rotted tissue is brown, soft and lifts away easily.

A cutworm chops the seedling cleanly off at ground level in one night (no rot, no smell) — foot rot is a slow brown rotting, not a clean cut. Drought or termites can also wilt a plant, but drought wilt recovers after watering and termites leave dry soil tunnels and mud, not a wet dark lesion. If the base is dark, soft and girdling after wet weather, it is foot rot.

foot rot hits hardest during the development and mid-season stages, when the plant is growing fast and carrying a heavy top. Check the field after every heavy rain or flood irrigation and during warm, muggy spells (about 18–28°C with wet, poorly drained soil is exactly what the fungus loves).

walk a big "W" across the field so you cover all four corners and the middle, not just the row by the path. Make about 10 stops along the W.

kneel at the plants and look at the stem base and collar right at the soil line — the part you'd normally never notice. Pull mulch and loose soil away from the collar, feel for soft or sunken spots, and check citrus trunks for gum blobs and peeling bark.

Walk the dips, the poorly drained corners, and the ends of furrows where water sits — foot rot almost always shows up there before the rest of the field.

the threshold is low because this disease spreads through the soil and kills what it touches. Even ONE plant showing a dark, girdling lesion or gumming at the stem base means act now — mark it, and treat it as a warning that the fungus is active in that wet spot and will spread to neighbours.

As soon as you find a girdled or gumming plant, dig it out with the soil around its roots and burn or bury it far from the field — don't throw it on the compost or leave it in the furrow, or it seeds the next outbreak. Scrape mulch and soil back from the collars of nearby plants to dry them out.

Only after drainage and sanitation, reach for a phosphonate product (a systemic fungicide — systemic means it is taken up inside the plant and moves in the sap, unlike a contact spray that only coats the surface). Apply it as a soil drench poured around the base, or as a trunk paint on high-value citrus; on wheat a seed treatment protects the young plants. Match the higher-value crops first.

cover your skin, eyes, nose and mouth; work in the cool of the morning or evening with the wind at your back so the spray blows away from you; keep it off food crops you'll eat soon, off open water, and away from children and bees; respect the pre-harvest interval (the number of days the label says you must wait between treating and picking, so no chemical is left on the food); and wash yourself and your tools well afterwards.

if new plants keep girdling after you've drained, sanitised and treated, the fungus is established in that ground. Stop replanting the same crop there — pull the worst plants, harvest whatever the healthy ones give you early rather than losing it, and rest that block from host crops for two or more seasons while you fix the drainage. On badly waterlogged land, cut your losses in the low spots and replant only on well-drained, ridged ground next season.