TYLCV symptoms on tomato
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As TYLCV spreads into new production areas it becomes just another of the hurdles which growers need to overcome to manage their tomato crops, writes Peter Mullins, national product development manager at Lefroy Valley.
Internationally, growers have learnt to live with TYLCV, despite the fact that from time to time there are major losses to the virus. It helps to understand how it occurs, and how growers have learnt to overcome it.
TYLCV is transmitted by “silverleaf whitefly” Bemisia tabaci Biotype B, which is different from the “greenhouse whitefly” which is not a vector. It takes the whitefly 15-30 minutes of feeding on infected plants to become infected, and then requires 24 hours of incubation within the insect before it can be transmitted to other plants. Then it only requires 15 minutes of feeding for it to infect new plants. The virus can then remain active in the insect for up to 3 weeks. Plants will begin to show symptoms in 2 to 3 weeks after infection. |
Internationally there have been major losses to TYLCV, because by the time symptoms are obvious on plants, damage is very difficult to limit. Experience has shown that if silverleaf white flies are kept out of the crop for particularly the first half of the crop, then losses are significantly reduced. The earlier the plants are infected the more potential losses are incurred.
The cornerstones for TYLCV control, are controlling whitefly ( reflective mulches, systemic insecticides, insect monitoring traps ), reducing the virus inoculum ( removing host weeds, timely slashing and ploughing in of harvested crops ), starting off with healthy plants. The use of resistant varieties assist in enhancing the effectiveness of this strategy.
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Lefroy Valleys trial programme evaluates tomato varieties under extreme TYLCV pressure and has yielded TYLCV varieties adapted to Australian conditions. The indeterminate gourmet LIBERTY, indeterminate roma SASSY, and indeterminate cherry tomato FELICITY all offer Fol 1-3 and TYLCV resistance, whilst the indeterminate cherry MARTYNI, and indeterminate grapes CARMINE & ORNELA offer TYLCV resistance.
The Lefroy Valley pipeline is healthy and there are several promising new varieties which will be shown to growers over the coming season to assist them to overcome this new challenge. |
Liberty, TYLCV resistant gourmet tomato
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