Wilt disease of pigeon pea

Host: Cajanus cajan (pigeon pea/Arhar)
Pathogen: Fusarium oxysporum f. udum Butler

Distribution

Wilt disease of pigeon pea was reported from Bihar state in India in 1906 by Butler. The disease is prevalent throughout the pigeon pea growing regions of the world including India, Kenya, Malawi, Tanzania and Mozambique. Wilt disease can cause 30-100% loss in grain yield (Pandey et al., 2013).

Symptoms

wilt of arhar
Photograph showing healthy (green) ans wilted (brown) plant of pigeon pea. Base of infected stem turns brown (in inset).

The disease usually occurs sporadically in the fields and infection is seen in few plants. Infection starts at the seedling stage. In infected plants leaves become pale, loose their turgidity and finally start drooping down. Infected plants show gradual wilting from bottom to top. Wilting occurs as a result of plugging of xylem vessels with fungal structures, which checks the water uptake. Infected stems show vascular browning. In severe infection entire plant wilts or dies within a days or two. Base of the infected stem (just above the soil) turns brown and scaly.


Causal organism

Wilt disease of pigeon pea is caused by Fusarium oxysporum f. udum. Its perfect stage is recognized as Gibberella indica. The fungus produces macroconidia, microconidia and chlamydospores.

Fusarium oxysporum
Transverse section of infected root of pigeon pea showing xylem vessel plugged by mycelium and conidial mass of Fusarium oxysporum udum (in red circles).

Macroconidia are produced successively at the end of short simple or clustered conidiophores and remain bound in a drop of liquid. Macroconidia are fusiform, multi-celled by transverse septa, with a characteristic foot-shaped basal cell and a pointed to whip-like apical cell. Microconidia are bacteria-like, white to salmon pink in color borne on shorter condiophores, become free as soon as objected. Fungus produces chlamydospores in nitrogen deprived culture medium.

Disease cycle and epidemiology

TDisease is soil-born. The pathogen can survive in infected debris is soils as a saprophyte for up to 3 years. On getting host, fungus enters though finer roots and cause primary infection. Disease is monocyclic as the infected plants wilt and die.

Control measures

Pathogen is soil-borne, therefore only chemical control is ineffective. The disease can by controlled by applying more than one method under integrated disease management (IDM).

Sources

  • Pande SU, Sharma MA, Guvvala GO. An updated review of biology, pathogenicity, epidemiology and management of wilt disease of pigeonpea (Cajanus cajan (L.) Millsp.). Journal of Food Legumes. 2013;26(1-2):1-4.
  • Prasad, P.S., Muhammad, S., Mahesh, M. and Kumar, G.N.V., 2012. Management of pigeonpea wilt caused by Fusarium udum Butler through integrated approaches. Journal of Biological Control, 26(4), pp.361-367.
  • Maisuria, V.B., Gohel, V., Mehta, A.N., Patel, R.R. and Chhatpar, H.S., 2008. Biological control of Fusarium wilt of pigeonpea by Pantoea dispersa, a field assessment. Annals of microbiology, 58(3), pp.411-419. https://annalsmicrobiology.biomedcentral.com/articles/10.1007/BF03175536


Content first created on 16-03-2021
last updated on 05-11-2021