Parsnip Canker
Parsnip canker can be a serious disease of parsnips especially in wet soils or during rainy seasons. Canker can manifest itself as spots, blotches and lesions that penetrate the crown, shoulder or sides of the parsnip root. Spores that are produced on foliage fall to the ground where they come in touch with the roots. There are 3 types of Parsnip canker which can affect parsnips; black canker, orange-brown canker, black-brown canker

The cause of black canker is fungal in origin Infection may be by Intersonilia pastinaceae or Phoma sp. The cause of orange-brown canker has not been defined and may be physiological in origin. Brown-black canker is also caused by fungal infection. Black canker is the most frequently occurring form.

Susceptible Plants- Parsnips , Hamburg Parsley    

Symptoms- Black canker causes dark lesions, often on lateral roots. Orange brown canker produces a brown coloration on the skin, initially on the shoulder of the main root. Black-brown canker produces a purple lesion with  brown water margins. Lesion size can vary from a few 1/8in( 6mm) to 8in(3cm). Young lesions are coarse or granular in appearance. Invasion of the lesions by secondary rot bacteria or fungi can cause rapid decay of the whole root.

 
Safer® Brand Garden Fungicide $12.50 
Intersonilia can remain active after foliage dieback, increasing the risk of canker in late harvested crops. Crops already weakened or damaged by pests are more readily infected than strongly growing crops. Crops already weakened or damaged by pests such as carrot rust fly are more readily infected than strongly growing crops.


Prevention and Control- Crop rotation:-Ideally do not grow on the same land within 4 years and avoid planting other susceptible crops such as beet, celery or carrots. Cereal breaks are the preferred option. Control carrot rust fly attack to avoid secondary infection by the pathogen.

Prompt disposal of debris to remove source of infection.  Plant crops in areas with good drainage. Short storage of crop when possible Use Parsnip canker resistant cultivars. Garden Fungicide is a naturally-derived sulfur based product which inhibits the attack of fungal diseases by creating an environment that is not optimal for disease growth


 



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