Growers should now be moving to winter rates of copper. Copper use reduces through summer and coverage needs to be rebuilt as the risk of frost and hail increases and wetter conditions prevail. Leaf spotting from spring infection still provides inoculum sources and heavy morning dews can provide sufficient moisture to re-activate Psa.
Growers beginning winter work on Gold3 are noting some dehydrated cane and cane die-back in their canopies; and some Hayward growers in the Katikati region have also commented they are seeing new spotting on Hayward leaves. This indicates recent Psa infection and reminds us that Psa has not disappeared.
Frost damage, leaf-fall, wounds created when dropping strung canes and pruning activities all create opportunity for Psa to enter. Therefore levels of inoculum in the canopy must be managed.
After harvest, a copper and Actigard™ mix is recommended if leaf condition remains strong (leaves must be actively photosynthesizing to maximise the value of Actigard™). Do not apply Actigard™ to stressed vines. Further applications of copper will be needed through the leaf-fall period and before and after winter pruning. Protection through dormancy presents much lower risk of phytotoxic effects.
Also, check the coverage of sprays applied. Slow down to maximise the value of the applied products and avoid product waste through run-off. Addition of spreaders will improve coverage and penetration into cracks and crevices. Time on target is important, and alternating the direction of travel for consecutive spray passes will help compensate for shadowing from pergola structures.
Linda Peacock, KVH Operations
It has been a year since the Kiwifruit Plant Certification Scheme (KPCS) was introduced through the launch of the ‘Core’ Standard.
During this time the Scheme has gained momentum with nurseries and growers. To date, four nurseries have met the Standard and are now selling certified plants; and KVH is working with other nurseries who intend to meet the requirements of the Standard and join the scheme.
Over the last year KVH has consulted with nurseries and growers, and hosted two KPCS workshops with members of the nursery, grower and science communities.
Engagement with the industry has been an important part of the development process and this feedback is now being incorporated to better improve the KPCS for nurseries and growers.
Yesterday an update was sent to all kiwifruit nurseries outlining the current status and future direction of the Scheme, and this included the move to one Standard only (initially a more rigorous, High-Health Standard was planned for development). The single standard will be no longer be referred to as the ‘Core’ Standard but the ‘KPCS Standard’. This change is reflective of the feedback and suggestions received from the nursery and grower communities.
Matt Dyck, KVH Biosecurity
MPI have completed a review of how costs are recovered from individuals and industries for food safety and biosecurity services and have updated a number of fees that will come into effect on 1 July 2015.
KVH has been involved in the consultation process of the Cost Recovery Review and supports a user-pays approach and changes to regulations and operating procedures that result in better biosecurity protection for our industry.
The user-pays approach is consistent with the new passenger surcharge at the border announced in the last week’s budget.
Details on the fee changes for biosecurity services are available on the MPI website.
Matt Dyck, KVH Biosecurity
Immature growth and leaves must remain protected through the autumn period with copper applications, particularly in frost-prone areas.
Many growers choose not to use frost protection as leaf-fall allows pruning to get underway. However, with frost comes the added risk of Psa movement into leaf and cane tissue.
Inoculum levels within the orchard must be minimised to avoid disease spread. Growers with frost protection, particularly those with windmills, should consider protecting high-risk blocks such as developing Gold3 canopies and young plants. Psa multiplication is rapid in frosted tissue and the colder the frost, the higher the risk.
Italian research also showed water-soaked leaves damaged by frost developed Psa in 100% of cases when sprayed with Psa inoculum vs 20% infection for non-frosted leaves.
Once plants harden off in winter this risks reduces. Males are likely to be vulnerable later into the season as they are often slower to lose their leaves.
Linda Peacock, KVH Operations
