As the spring weather is bringing on bud break in the kiwifruit, Te Puke orchardists are learning how far the vine canker Psa has spread over the winter.

This week, 21 Te Puke orchards have confirmed Psa V bringing the total infected orchards to 228. One is in the Tauranga region.

A Psa infected leaf.

Kiwifruit Vine Health Incorporated is expected to say today whether antibiotic sprays are to be included in the range of responses to the infection.

'It's going to be over to the individual growers to decide what protectant options they use,” says KVH chairman John Burke.

'There's a whole range they can use – we are not saying you have to use it, it is totally voluntary, but it is one of the weapons that is potentially available for growers to consider. We still have to make the final call on that.

'The rate of infection has increased quite dramatically as we go into bud break. With the sap starting to flow on vines we are seeing more infection levels, especially all in Gold. 'There's a lot at stake here. We are being totally responsible about the way we approach this, but we want to be also as effective as possible.”

KVH is going through a process to look at all the concerns among growers and other service providers including beekeepers, says John.

In reply to concerns expressed by Independent Kiwifruit Growers, John says Italian kiwifruit growers have not used the antibiotic being considered by KVH.

'We know that it has a very good knock down ability against the disease,” says John.

'It hasn't got a lot of persistence and that's one of the good things.

'It disappears very quickly under ultra violet light, but it does bowl out the Psa very quickly.

'What we are wanting to do with our coordinated spraying strategy is knock down Psa levels as much as we can and hope for some favourable weather conditions to try and hold back the disease.”

In the Lazio region in Italy, Hort16A orchards lost about 40 per cent of production in 2010.

In 2011, 100 per cent of Italian orchards have some level of infection and an estimated 85 per cent of Hort16A vines have been removed.

Italian growers of the yellow Jin Tao variety are reporting up to 100 per cent infection.

Italian Hayward growers are estimated to have 15-30 per cent infected compared with 5-10 per cent in 2010.

Psa was first documented in Italy in 1992, but in 2008 the symptoms of Psa became much more dramatic.