Kiwifruit disease outbreak spreading

These brown spots on a kiwifruit leaf are symptoms of the potentially serious bacterial disease Psa. File photo / NZ Herald

Kiwifruit disease Psa V is taking a firmer grip and its spread more aggressive than expected, the industry reported today.

Seeka Kiwifruit Industries said the disease had continued to spread throughout the Te Puke region in the Bay of Plenty, and into new areas.

It had now been found in the Matapihi area, on the outskirts of Tauranga.

"This is seen to be a significant deterioration in the situation, with spread of the disease outside the previously affected geographic areas," Seeka said.

Generally across the industry, detections had increased with 19 Psa V confirmations in the past week. A total of 170 orchards had now been affected across a wide area.

The gold kiwifruit variety continued to be particularly susceptible, while secondary infections were seen in the green variety in only a small number of cases, Seeka said.

"The spread over the winter months has been more aggressive than expected."

Laboratory-confirmed incidences of the disease, or secondary symptoms, had been seen on Seeka supplying orchards covering 200ha of green and 138ha of gold kiwifruit.

Gold orchards were generally severely affected, while green orchards were showing only light symptoms.

Laboratory tests had confirmed Psa V as having been present in two of Seeka's long-term lease orchards. In one orchard covering 15.8ha of gold and 5.57ha of green the infected plant had been removed and there had been no evidence of further infection to date.

In the other orchard covering 16.6ha of gold, efforts to contain the infection had not been successful.

Growers Seeka and EastPack have formed a taskforce to search for a scientific solution to fight Psa V.

- NZPA