Identification Symptoms
- Early symptoms are most commonly
observed under the plant canopy, on lower leaves, stems, and tendrils,
where conditions are more humid.
- Symptoms first appear as small,
purplish-brown and irregular flecks.
- Under continued humid conditions,
the flecks enlarge and coalesce, resulting the lower leaves becoming
completely blighted.
- Severe infections may lead to
girdling of the stem near the soil line, which is known as foot rot.
- Foot rot lesions are purplish-black
in colour and may extend above and below the soil line.
- Foot and stem lesions girdle and
weaken the stem, leading to crop lodging and yield loss.
- Disease lesions develop on pods
under prolonged moist conditions or if the crop has lodged.
- Pod lesions are initially small and
dark, but may become extensive and lead to early pod senescence.
- Severe pod infection may result in
small, shrunken or discoloured seed; or alternatively, seed may show no
symptoms