Case Study Update: Yarra Valley VIC, February 2019


Orchardist: David and Sue Finger
Location: Launching place, Yarra Valley VIC
What are the main IPDM issues being focussed on? Main concerns are black spot and codling moth but mites, birds, heliothis, kangaroos and fruit bats are becoming issues.

 

What are you doing currently with IPDM? I am using RIMPRO to guide my spray timing for black spot and codling moth and powdery mildew. I have released a range of predatory mites for control of my mite complex (I have TSM, ERM, and bryobia as pests). I am experimenting with bamboo bug traps to capture earwigs and they are also capturing ants. I haven’t thought about distributing the earwigs to help with codling moth and WAA control, probably because this year earwigs are already widespread and numerous. Aphelinus mali is present in good numbers so I am trying to restrict insecticide use and to use ‘softer’ products where possible. I maintain a weed-free tree-line but don’t worry too much about weeds in the inter-row because I root-prune to control vigour, which means that the weeds are probably not competing with the trees. When I do mow I use a narrow mulching mower that leaves some weeds at the edges to support predators.

 

What has worked well? What hasn’t? Combining RIMPRO with MetEye provides extra weather data, such as wind speed, including 7 day forecasts that help with planning orchard operations (especially spray applications). Leaving a narrow strip of weeds on the outside of the mown inter-row area does not appear to be causing any harm but I have not evaluated if it has helped predator populations.

 

I am a bit disappointed in the performance of mite predators this year because I am having trouble controlling mites despite very good predator numbers. I have occidentalis, californicus, and persimilis so maybe there is some predation of each other? Maybe some impact of Altacor? I have had a rising mite issue since introducing Altacor which may only be coincidence but…? Maybe they don’t like the heat (we have had very hot weather this year)?

What would you do differently next time? I am going to try to reduce the use of Altacor by reintroducing pheromones to my program, consider the use of Vertimec early, more strategic release of predatory mites, and then try to track the impact.

 

Any interesting learnings? Pest management (and fruit growing) is a dynamic system with a lot of interactions going on. No single recipe or prescriptive guidelines can cater for it. We need to think carefully about possible side effects of whatever we do and weigh the benefits against the costs. Most of all we need to train all our people in the orchard to observe and report their observations before we make decisions about spraying and the products we use and their likely impacts.

 

Take home message We have a lot of tools that generate information but the suppliers are not always out on the front line. The users (decision makers) need to ground truth this with good situational awareness to interpret the outputs and advice to suit their context.

 

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