Chilli Damping off

Causal organism: Pythium aphanidermatum
Family: Pythiaceae
Order: Peranosporales
Class: Oomycetes
Sub. Division: Mastigomycotina

Damping off is very common disease in nurseries. The disease appears immediately after the onset of monsoon rains.

                                                                        

                                                                                          Damping off

Symptoms:

1. Seed may rot or the seedlings may be killed before they emerge from the soil. Stem of young seedlings may also be attacked after emergence showing water soaking lesions and shriveling of stem which fall over and die.
2. In nursery the disease may appear in patches in 2-4 days, the entire lot of seedling may be destroyed.

Dieing of seedlings in patches

Dieback of seedlings

Disease cycle:

Primary source of inoculum: Oospores in soil or plant debris.

Secondary source of inoculum: Zoospores through irrigation water.

It also infects Tomato, Cabbage, Brinjal, Tobacco, Radish, and Cauliflower.

Epidemiology:

High soil moisture and relatively higher soil temperature favor the rapid development of the disease. The disease is further aggravated in ill-aerated soils with poor drainage having thick stand of the seedlings.