43 new Psa-V cases discovered as vine-killer spreads

The kiwifruit vine-killing disease Psa-V is continuing to spread throughout the Western Bay and further afield.

Forty-three new cases have been discovered this week - 21 in Te Puke, seven in Katikati, five in Tauranga east, four in Tauranga west, two in Waikato, two in Franklin, one in Opotiki and one in Hawkes Bay. This brings the total number of infected orchards to 1669.

Kiwifruit Vine Health (KVH), the organisation established to lead the fight against Psa, released the figures.

Since the first case of Psa-V was identified in the Hawkes Bay last Friday, no other orchards near the affected Taradale Hort16A orchard have reported symptoms of Psa-V.

A "controlled area" was established around the affected orchard and included 43 nearby orchards.

KVH representatives met with about 50 Hawkes Bay growers on Monday and updated them on the situation and provided them with advice to help protect their orchards in a Psa-V environment.

In the latest KVH bulletin, the organisation said male vines often expressed Psa-V symptoms before female vines. It had been seen in Hort16A, new varieties and Hayward.

"While this observation may be due to some male varieties having a lower tolerance to Psa-V, it is also likely that incomplete spray programmes, poor spray coverage and infection through late season growth, have contributed to these levels of infection."

Meanwhile, canopies with medium-to-low vigour wood appear to have less infection, KVH said. "This is possibly due to the wood being mature and hardened off by autumn, when the risk of Psa-V infection through green tissue is high."