As growers in New Zealand begin applying copper spray to a number of kiwifruit orchards affected by the bacterial disease PSA, a leading representative from Zespri Europe has warned that it will take some time before a similar outbreak in Italy is brought under control.
Over the past year, kiwifruit producers in the Italian regions of Lazio and Emilia-Romagna have been faced with one of the worst outbreaks of PSA on record, a development thought to have been caused by a cold, wet winter followed by cool, damp conditions in the spring of 2010.
Partly as a result of the spread of PSA – known also as batteriosi in Italy - this season’s yellow-fleshed kiwifruit crop in Lazio is set to be around 37 per cent smaller at 9,164 tonnes.
The value of Lazio's yellow-fleshed kiwifruit sales, meanwhile, which includes a sizeable proportion of Hort16A (the variety marketed exclusively as Zespri Gold), has reportedly been cut by around €9m due to the outbreak.
Zespri Europe has begun marketing its European kiwifruit this week, but question marks remain over both the potential volume available in Europe this season and the potential expansion of production in the continent over the next few years.
"Until more is known about the disease, the environmental conditions it prefers and suitable control options, it is difficult to predict the future," commented Blair Hamill, Zespri's commercial manager based in Italy, in an exclusive interview published by Eurofruit this month.
"Batteriosi is managed in Asian countries to the extent that it is not a major limitation on production. Extremely cold and wet winters, followed by cool wet springs appear to be the prime climatic conditions for the disease to establish and spread quickly."
Mr Hamill says improvements to crop management techniques and better weather conditions should mean PSA's grip on Italian kiwifruit production will be weaker in 2011.
"We are hoping for a good winter weather-wise and this, coupled with the fact that inoculum levels should be falling, given the best practice growers have been employing, will hopefully result in less infection than we have seen in the previous two winters," he said.
Mr Hamill also revealed that Zespri has begun testing production of its three new cultivars – known only as G3, G9 and G14 – on trial orchards situated in both Lazio and Emilia-Romagna in Italy, as well as a further trial site in France.
"Obviously we are very interested in seeing how these varieties perform in conditions outside New Zealand, with the aim being to supply customers year round. To meet this objective, these varieties will need to be grown and supplied outside of New Zealand," he commented.
"It is too early to say how much we will plant in locations outside New Zealand. First we must see how the trials go and continue to assess the orchard, storage, shipping and consumer performance of these varieties grown in New Zealand."
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