Turnip Mosaic Virus of Brassicas

TMV

Description:

A viral disease of Brassica crops.

Broccoli, Cabbage, Cauliflower and Brussels Sprouts.

It starts as yellow rings on the youngest leave and progresses to a mosaic of rings and blotches of varying colour. In colder weather it may show as black necrotic ring spots and patches.

Canola, Chinese Cabbage, Mustard, Radish.

It usually shows as a mottled mosaic with tissue death and leaf distortion

Swede and Turnip.

It usually shows as clearing of the veins on the youngest leaves followed by a dark green ring pattern and coarse mottle.

Stocks.

Leaves may be wrinkled and distorted with patches of lighter coloured mottling. Plants may be stunted and flowers streaked with white or lighter colours.

Species Affected:

Brassicas.
Alyssum, Broccoli, Brussels Sprouts, Canola, Cauliflowers, Charlock, Chinese Cabbage, Field Cress, Honesty, Lettuce, Mustard, Radish, Shepherds Purse, Stock, Swede, Turnip, Wallflowers, Wild Mustards, Wild Turnip.
Cabbage is extremely susceptible.
Radish and Turnip are very susceptible.
Superette is a resistant variety of Cabbage.

Biology:

Occurs on many Brassicaceae species and Lettuce.
Warm dry conditions favour the aphids that spread the disease.
Survives in crop residues and on Brassica weeds.
Spread by aphids such as the Green Peach Aphid, Cabbage Aphid and others.
Cabbage is more sensitive than other species.

Life Cycle:

Transmitted by Aphids usually early in the season.
Cabbage Aphids, Green Peach Aphids and Turnip Aphids and others transmit it in Canola.

Origin and History:

Distribution:

Significance:

Yields of Canola may be reduced when the crop is infected early and levels of infection are high.

Management and Control:

Plant healthy seed.
Remove crop residues.
Control Brassica weeds and other hosts in the crop and adjacent areas.
Adjust planting date so young crops aren't exposed to periods of high aphid numbers.
Apply anti-feeding aphicides before aphid numbers build up.
Avoid continuous cropping of Brassicas.
Remove and destroy infected seedlings and plants.

Related and Similar Species:

Beet Western Yellows Virus
Cauliflower Mosaic Virus

References:

1291

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.