One kiwi fruit grower in the Bay of Plenty has discovered a disease in his orchard which has frightened all kiwi fruit growers in the area. Tests have shown that the disease is PSA although they don’t yet know which type of PSA it is. This disease is caused by bacteria. The bacteria are spread by wind pollination so it could affect other orchards. PSA has caused a 50% drop in kiwi fruit harvest in Italy and there are fears that this could happen here. It seems to affect only the golden kiwi fruit plants. Our kiwi fruit industry is worth more than $1bn.
How did these bacteria arrive in New Zealand when we have such strict bio-security controls at the airports? Maybe someone brought a diseased plant into the country and this was not discovered at the airport. It is possible that the bacteria have been dormant in the orchard for many years but because of different weather – maybe more rain than usual – the plants are now affected. The first signs are black spots on the leaves.
MAF – the Ministry of Agriculture and Fisheries – is doing all it can to stop this disease from spreading. The affected orchard and another one close by, are in quarantine. No one may enter. On all other kiwi fruit orchards, workers spray their boots and tools with disinfectant.
MAF thinks that the climate and soil in the Bay of Plenty, where most kiwi fruit are grown, are different from Italy. This could mean that the disease will not do much damage here.
The disease cannot spread from the fruit. That is still safe to eat and safe to export.
To find out more about biosecurity problems listen to March 25th 2010
Questions
1. How is it possible for diseased plants to enter New Zealand?
2. Have you heard of “foot and mouth” disease that can affect animals? Could this be similar?
3. Do you know the expression “to put all your eggs in one basket”? In the Bay of Plenty, most growers are kiwi fruit growers. Can you see why they are seriously worried? |