Pomegranate wilt: Knots on fine roots
Pathogen: Meloidogyne incognita (nematode)
Symptoms
Affected plants show yellowing of leaves in some twigs or branches, followed by drooping and drying of leaves. If observed:
Brown/grey/black discoloration of wood then its Ceratocystis fimbriata
Only xylem is brown then its, Fusarium oxysporum
Knots on fine roots its nematode infestation
Disease development
The pathogen spreads through infected seedlings. Pruning wounds are common entry points for C. fimbriata, and the fungus can also be carried on pruning tools and through air. Spread to adjacent trees can take place via root grafts generally in plantation at close spacing. Flood irrigation/rain water also spread the pathogens from the infected plant/s to healthy plants. Wounds in the roots made by insects, nematodes and rodents also predispose the plant to wilt pathogens.
Control
Follow spacing of 4.5x3.0 m in the orchard in sandy loam soil with proper drainage.Soil drenching with carbendazim (0.2%) or propiconazole (0.15%) or tridemorph (0.15%) + Chlorpyriphos (0.25%).