1. WHITE RUST / BLISTER- Albugo cruciferarum
Isolated, raised and shiny white pustules develop on leaves and stem. In severe cases, the entire plant may remain dwarf and only small leaves are formed. The pathogen is an obligate parasite.
Mode of spread and survival
The infection takes place through seed borne inoculum and the pathogen survives as oospores in soil
Rain with low temperature at flowering stage encourage the disease development
- Seed treatment with metalaxyl @ 2 g/kg of seed
- Spray mancozeb or captafol @ 1 kg/ha
- Grow disease resistant varieties like T 4 and YRT 3
2. LEAF BLIGHT- Alternaria brassicae
Small black coloured areas of circular lesions with concentric rings are formed. The disease reduces the size of fruits and number of seeds.
Mode of spread
The pathogen spreads through wind borne conidia
The pathogen is externally and internally seed borne
Rainy weather encourage the disease development
- Spray mancozeb or zineb or captafol @ 1 kg/ha
- Remove and destroy the infected plant debris