Source: Hindustan Times [summ., edited]
Cabbage crops in parts of Kangra district [Himachal Pradesh] have been hit by blackleg disease. Scientists from Himachal Pradesh Agricultural University (HPAU) have visited the area. Farmers have been told to treat the crop with copper or other fungicides and also use fungicides while sowing. Infected plants are to be destroyed and drainage of water in fields should be ensured. A monoculture of cabbage crops increases the disease risk.
[Blackleg (also called phoma stem canker or leaf spot) is the most serious disease of crops in the Brassicaceae family with a possible yield loss of 50 percent or more. The fungus _Leptosphaeria maculans_ causes severe diseases affecting vegetable brassicas including various cabbages, as well as oilseed rape, turnip, radish, and brassicaceous weeds which may serve as pathogen reservoirs. Depending on the host, symptoms may include lesions on leaves, stems and seed pods, with stem cankers leading to premature ripening or collapse of the plant. Root infections have also been reported (ProMED post 20010819.1959). Symptomless infections may occur.
The fungus is seed borne and also spread by wind, splash dispersal, mechanical means (for example on contaminated equipment), and infected plant litter. They may overwinter in crop residues, which are therefore often sprayed with fungicides. However, this does not eliminate the risk from remaining underground parts of infected plants. Disease management includes use of clean seed, cultural practices to minimise inoculum, and fungicides. Cultivars with different levels of disease resistance are available for some of the crops. However, the pathogen is extremely diverse and new strains evolve frequently that can overcome host resistances or show new fungicide resistances. Pathogen adaptation may be counteracted by frequent changing of crop cultivars and/or mixing fungicides with different modes of action.
The fungus _Plenodomus biglobosus_ has been reported in some areas in association with milder blackleg symptoms.
India (with states):
Blackleg on vegetable brassicas and radishes:
Blackleg on oilseed rape:
Information on blackleg of cabbages and radish:
Blackleg of oilseed rape:
_L. maculans_ taxonomy and synonyms:
Other fungal taxonomy via: