Tomatoes NZ and The Ministry for Primary Industries are trying to identify a strain of disease discovered on tomato plants.
Pepino Mosaci Virus, which affects the yields of plants and delays growth of the fruit, was found in an Auckland greenhouse in April and has since spread to three other commercial greenhouses in that area.
The virus (PepMV) can cause pepino mosaic disease in tomatoes and some other solanaceous plants, including potatoes and eggplants.
The disease can affect production but has no impact on food safety or human health. Tomatoes are still safe to eat.
The ministry nevertheless has temporarily suspended export certification to six countries including Australia, Japan and Fiji, and commercial growers are being advised to closely monitor their crops for signs of the virus.
Affected glasshouse operations have been able to continue growing and selling product within New Zealand under heightened hygiene measures.
Investigations continue into how the virus may have entered New Zealand and how widespread it has become.
It is not yet certain how seriously PepMV would affect tomato crops in this country. It appears to have minor foliage effects on younger plants, but as the plant ages, can cause mottling of the fruit itself.
Biosecurity New Zealand is working with Government Industry Agreement (GIA) partners Tomatoes NZ, Vegetables NZ, Process Vegetables New Zealand, and the New Zealand Plant Producers Incorporated (NZPPI) to determine the scale of the situation and the most appropriate measures to manage it.
Affected plants can show stunted growth or symptoms resembling hormonal herbicide damage. Leaves around the head of the plant may show dark spots and distortion. Lower leaves may have brown, necrotic lesions.
Other leaf symptoms may be yellow spots which later develop into bright yellow patches on the leaf and ‘bubbling’ on the leaf surface.
Fruit can appear ‘marbled’ and this may be more readily seen on large red tomato varieties.
PepMV is spread on seed, stalks, and leaves and through plant-to-plant contact and propagation. It is also transmitted easily on contaminated tools, hands and clothing.
Bumblebees used as pollinators are known to spread the disease.
While the virus can be detected in the fruit itself, the risk of transmission of the disease through selling fruit is considered low.
Find out more about pepino mosaic virus [PDF, 871 KB]
Source: RNZ and the Ministry for Primary Production