Psa-V has progressed significantly this season in Chile; with an unusually wet spring being the likely contributor. Disease severity is high in all varieties and the Chilean kiwifruit industry is predicting a potential drop in production as a result.
Bud-rot and leaf spotting symptoms are widespread in Hayward varieties; and other varieties (Hong Yang, Enza Gold, Jintao and Summer Kiwi) that were already infected are showing more severe symptoms such as cane dieback and exudate.
The disease has continued to spread north and the first infected orchard in the northern ‘Metropolitan region’ has recently been identified.
Latest figures released by Chile’s Agriculture and Livestock Service confirms 17 new orchards have been confirmed Psa-V positive, bringing the total of infected orchards to 180 – an area of approximately 1,900 hectares.
The Chilean Kiwifruit Committee continues to encourage growers to adopt strict hygiene measures, particularly tool hygiene between vines, regular monitoring and movement controls to prevent further spread.
KVH has recently completed monitoring rounds in the Whangarei and North-West Auckland regions.
Two rounds of monitoring were carried out in the Whangarei region. The first round in late September focused on the ten orchards immediately surrounding the Psa-V positive orchard—a total of 29.41 hectares. Samples from four orchards were tested and all returned a ‘Not Detected’ result.
The second round of monitoring was carried out in mid-October and focussed on the Hort16A blocks within the controlled area and the closest orchards to the positive orchard. This included a total of 11 orchards representing 41.2 hectares. Samples from three of these orchards were tested and also returned ‘Not Detected’ results.
There are several messages for growers based on information gathered on these rounds of monitoring – click here for them.
The monitoring round in North-West Auckland was completed in early November and included 11 of the region’s 23 orchards located closest to the two positive orchards in the region. Click here for the report.
Samples from five orchards were tested; and one Hayward orchard was confirmed Psa-V from the testing. Symptoms included cane dieback and exudate on two adjacent male vines. The orchard is located approximately 30m from the first positive orchard in the region (confirmed in November 2013).
The two existing positive orchards in the region (now G3 plantings) were showing symptoms right across the orchard, including cane dieback and exudate on stumps and new grafts.
North-West Auckland is currently an ‘Exclusion’ region with a controlled area in place – the status is likely to be re-considered at the end of spring.
Growers are reminded to be vigilant about inspecting their vines for Psa-V symptoms and maintain a protectant spray programme.
The use of KeyStrepto™ this season is quickly coming to an end. Growers are reminded KeyStrepto™ cannot be applied within seven days of the first flower opening.
While some Hayward orchards may still be outside of the seven-day window, this window is rapidly closing. Growers are urged to be cautious if applying KeyStrepto™ to ensure they stay well outside of the seven days before flowering period.
Most orchards are well into flowering and KeyStrepto™ use is no longer permitted.
There is still time for growers of green varieties with little or no male infection to consider making their orchard available for flower picking to support their own and industry stocks. Early male flowers can be collected for pollen without impacting on pollination.
Growers supplying flowers are asked to assess their orchards to avoid infected areas and monitor pickers to ensure infected flowers are not picked.
Several pollen mills have commenced milling this season; KVH will be auditing them over the coming weeks.
KVH has prepared a submission on behalf of the kiwifruit industry on MPI’s proposed changes to the Import Health Standard (IHS) for vehicles, machinery and tyres.
One of the main proposed changes to the Standard, which is of concern to the kiwifruit industry, is the proposal to reduce treatments for Brown Marmorated Stink Bug (BMSB) that apply to vehicles and machinery imported from the USA. The MPI proposal is that these requirements be reduced from ‘year-round’ to a defined ‘stink bug season’ only (September to April).
BMSB is one of the kiwifruit industry’s ‘Most Unwanted’ pests. It affects multiple crops and is a serious public nuisance pest. Vehicles imported from the USA have demonstrated to be the highest risk pathway for this pest, given the serious nature of the outbreak there.
MPI and industries, including the kiwifruit industry, have an active programme in place to keep BMSB out of NZ and be prepared if it arrives. This includes heightened measures at the border and offshore, national and regional awareness campaigns and a significant programme of research and response planning.
While the number of stink bugs intercepted at the border is low outside of the proposed stink bug season, US experience and molecular studies suggest it only takes a small number of individuals (as low as two individuals) for this organism to establish. And this is possible outside of the proposed ‘stink bug season’ (our autumn/winter period) in warmer northern parts of NZ and suitable microclimates.
KVH believes continuing year-round offshore treatment of US imported vehicles and machinery is technically justified and is urging the government to maintain this. KVH is also calling for further strengthening of protection against BMSB through joint action under Government Industry Agreements (GIA).
Click here for the full KVH submission.