Vol. 7, Issue 7 (2018)

Author(s):
Anil Sharma, JP Rathore, Ahmad Ali, Injila Qadri, Syed Mazahir Hussain and Tashi Angmo

Abstract:
Disease ecology means, the study of organisms that cause plant diseases in relation to their environment. Diseases are caused by pathogens (disease organisms) that include fungi, bacteria, viruses and nematodes. Most pathogens spread from infected plant material or soil. They are carried by wind, water (rain, irrigation water, ground water), insects, and by humans or tools (attached to clothing or shoes, and spread by pruning or cultivation tools). Cabbage is an important component of the human diet and a source of chemoprotective phytochemicals. Six major diseases of cabbage found worldwide are black rot, clubroot, black spot (dark spot), downy mildew, watery soft rot (white mold), and wirestem. The pathogens causing black rot and black spot can be seedborne. The pathogens causing clubroot, watery soft rot, and wirestem are soilborne; the clubroot organism is remarkably difficult to eradicate from infested soils. Important control measures include seed treatment with hot water or fungicides, crop rotation to reduce survival of foliar pathogens, scouting to detect disease outbreaks, and judicious application of protectant fungicides. Further research is needed to clarify races of the downy mildew and club root pathogens and to find useful resistance to these two diseases. Cabbage diseases are the chief limiting factor in profitable commercial cabbage growing in India. The most destructive of these are black leg, black-rot, and cabbage yellows. Any one may destroy the greater portion of a crop.