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Alternaria Leaf & Head Spot top
  
Alternaria leaf and head spot are caused by Alternaria brassicae and A. brassicicola. Symptoms first appear as brownish-black, target-like spots on leaves and stems that spread to the head under wet conditions.
Suggested Management: Use high quality and disease-free* seed. Apply fungicides when needed.
Bacterial Soft Rot top
Bacterial soft rot, is caused by several species of bacteria (Erwinia and Pseudomonas). Symptoms initially appear as water soaked areas on wounded leaves. As the disease progresses, leaves become soft and begin to liquify.
Suggested Management: Avoid wounding plants during cultivation and harvesting. Control insects. Bury crop residue and rotate with corn or small grain to reduce bacterial populations in the soil. Avoid use of irrigation water from ponds and streams located near crucifer production fields.
Black Leg top
 
Black leg is caused by the fungus Leptosphaeria maculans. Symptoms first appear as black, round spots on leaves and stems. As the disease progresses, spots enlarge and become gray in the center with small black dots. Severely infected plants are stunted and may have a constricted stem at the soil surface.
Suggested Management: Use high quaulity and disease-free* seed and transplants. Bury and destroy crop residue and rotate with a non-crucifer crop for at least two years. Apply fungicides when needed.
Black Rot top
 
  
Black rot is caused by the bacterium Xanthomonas campestris pv. campesris. Black rot symptoms appear initially as V-shaped areas along the outer leaf edges. As the disease progresses leaf veins turn black, plants become stunted, wilt and usually die.
Suggested Management: Use high quality and disease-free* seed and transplants, bury and destroy crop residues and rotate with a non-crucifer crop for at least two years. Tolerant varieties are available.
Club Root top
 
 
Club root is caused by the soil organism Plasmodiophora brassicae. Club root symptoms include leaf wiliting and yellowing (particularly on hot, sunny days), stunted growth, and club-like galls on roots.
Suggested Management: Use high quality and disease-free* transplants. Avoid moving infected transplants and/or infested soil on farm equipment. Maintain soil pH at or above 7.3 by incorporating hydrated lime in the row immediately prior to planting. Avoid planting in poorly drained soils. Consider the use of PCMB fungicide in transplant water prior to planting.
Downy Mildew top
 
Downy mildew is caused by the fungus Peronospora parasitica. Symptoms first appear as purplish, irregular spots on leaves and stems. In the early morning, a purplish, fluffy growth is evident on the underside of diseased leaves. Cauliflower heads and stems can be invaded internally by the downy mildew fungus.
Suggested Management: Tolerant varieties are available. Apply fungicides. Bury and destroy crop residue and rotate with a non-crucifer crop for at least two years.
Fusarium Yellows top
  
Fusarium yellows is caused by the soil fungus Fusarium oxysporum f. sp. conglutinans. Symptoms first appear as a yellowing of lower leaves. As the disease progresses, wilting (often on one side of the leaf or plant) and plant death usually occur.
Suggested Management: Use high quality and disease-free* transplants and resistant varieties.
Sclerotinia Head Rot top
 
 
Sclerotinia head rot is caused by the fungus Sclerotinia sclerotiorum. Symptoms first appear as water-soaked spots on leaves. As the disease progresses, white cottony fungal growth appears on infected leaves with small black structures called sclerotia.
Suggested Management: Avoid planting in fields with a history of Sclerotinia disease, maintain adequate fertility, proper insect and weed management.
Rhizoctonia top
  
Several Rhizoctonia diseases (damping-off, wirestem, and bottom rot) are caused by the soil fungus Rhizoctonia solani. Damping-off symptoms appear as brownish lesions on stems and roots. Infected seedlings not killed by the fungus may later develop a constricted stem near the soil surface (wirestem). As the cabbage plant develops, the fungus causes a dark discolored area on the bottom of the cabbage head (bottom rot).
Suggested Management: Use a biological or chemical-based soil treatment to reduce damping-off. Plant seed when soil temperatures are favorable for germination and seedling emergence. Use high quality and disease-free* transplants.
*Although most crucifer seedlots are routinely assayed for seedborne pathogens by seed producing companies, there is no guarantee that the seed is 100% free from disease causing bacteria and fungi.
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