TURNIP MOSAIC VIRUS (TUMV)

This virus belongs to the potyvirus group and was first reported in USA. It is distributed worldwide and transmitted non-persistently by aphids, but not seed- borne. The incidence and severity of effects in canola crops is not as great as TuYV.

What to Look For

In turnips, TuMV shows pale chlorotic or necrotic local lesions. Systemic vein clearing and veinal flecking developing into severe mosaic and stunting of the plant. Similar symptoms are observed in canola, (Figure 10.25).

Figure 10.25 TuMV symptoms in canola

Disease Cycle

The virus is transmitted non-persistently by aphids and through sap inoculations. It is not seed-borne. The virus over-summers in weed species or in rape mustard sown for fodder in summer; aphids then transfer the virus into canola crops.

Further Information

More detailed information can be obtained from the DEDJTR AgNotes Series www.vic.gov.au/graindiseases

Victorian Pulse Diseases Guide www.vic.gov.au/pulsediseaseguide

Victorian Winter Crop Summary www.vic.gov.au/victorianwintercropsummary

Seed Health Testing in Pulse Crops (AG1250) www.vic.gov.au/seedtestingpulsecrops

Pulse Seed Treatments and Foliar Fungicides www.pulseaus.com.au/storage/app/media/crops/2011_APB-Pulse-seed-treatments-foliar-fungicides.pdf

Pulse Australia www.pulseaus.com.au

AsureQuality 3-5 Lillee Crescent (PO Box 1335) Tullamarine Vic 3043

AGWEST Plant Laboratories Department of Agriculture Western Australia, South Perth, WA 6151

TURNIP YELLOWS VIRUS (TUYV) (SYNONYM: BWYV)

Canola