IPDM all part of the award-winning strategyResearch & Extension
Written by Dr Paul Horne, IPM Technologies.
A commitment to Integrated Pest and Disease Management (IPDM) is a shared strategy for two of the horticulture industry’s award-winning growers.
Jason Shields from Plunkett Orchards in the Goulburn Valley, and winner of both the APAL and the Hort Innovation Grower of the Year award, has concluded the best long-term IPDM solution is to strategically hold back on spraying; in other words, to do nothing at all.
For Daniel Hoffmann, a vegetable grower from Virginia in South Australia and Hort Innovation Young Grower of the Year, release and moderation of a natural predator has controlled his pest problem.
Both growers have worked in recent years with entomologists from IPM Technologies to develop and implement suitable strategies for their farms, and their reasons for wanting to take this approach are also similar. Their prime motivation isn’t to save money on insecticides (although that has certainly happened) but to achieve sustainable control of pests and high quality of product with less reliance on insecticides and miticides.
Plunkett Orchards is a farm in the Goulburn Valley with around 150ha of apples and pears. Jason was interested in tying an IPM approach because “it seemed like every year we were using more and more chemistry and getting no better results, and even worse results in some cases”.
Using an IPDM approach at Plunkett Orchards meant changes to more than just the spray programme. Cultural management controls were extremely important and involved serious decisions about tree-height, canopy management, inter-row vegetation, and spraying equipment delivery.
What are the benefits now?
“We have had amazing results with 100% control of secondary pests like Mites, Mealybug, Woolly aphid, and scale without needing to use any target chemistry towards these pests,” said Jason.
“In the past we could use up to 3-5 mealybug sprays and still not have adequate control. This has also led to a saving of around 65% in insecticide cost with improved control.
“We have changed approach from reactive to consequence driven. A great example of this was scale in the previous season. Over the last 5 years scale has slowly built up by the end of the season and we sprayed due to our reactive approach. But the severity was getting worse each year, so obviously in the long term this approach wasn’t working. We bit the bullet and didn’t react and spray believing the consequence of this would be the predators would build up and do the job.
“In the end we had the same level or slightly higher of damage as the previous year, but this season the problem was non-existent. So many times in the last 12 months I was asked what I was going to do to control Scale because it had become a big problem. In the end not reacting was the best option and doing nothing gave us the best results in 5 years”.
Some of the key pests are the same for both Daniel and Jason Shields, with one being two-spotted mite. In the last 12 months, neither grower has used any miticides against this pest. This is a very different scenario for both than what was commonplace say 10 years ago. At Plunkett Orchards, Jason would have previously have normally used one application everywhere and sometimes two or three applications in hot spots. In Virginia, Daniel had previously been spraying for two-spotted mite on a fortnightly basis over the warmer months.
Daniel runs a farm that totals 11 acres but has polytunnels with a total area of 14,400 square metres. He has experience growing tomatoes, capsicum, eggplant, zucchini, and cucumbers but now he concentrates mostly on Roma tomatoes.
In addition to the main crop of tomatoes which are grown in polyhouses, Daniel also grows crops such as spinach, broccoli, cabbage, Asian greens, spring onions, snow peas, various beans, chillies, and herbs (mostly grown outdoors). These crops are grown for sale at local farmers markets, and he is also carrying out small-scale trials on growing other crops such as pumpkin, rockmelon, long melon, and dragon fruit.
Daniel puts it simply: “Insects like western flower thrips are basically impossible to control with insecticides in Virginia now.”
Commercially reared beneficial insects and mites have been key to management, though it’s important to maintain a balance between pests and their natural enemies on his farms (See page 20 of this December 2018 issue of Vegetables Australia magazine for more about pest balance).
“While growing tomatoes, I’ve found a way to maintain Nesid numbers without commercial releases by planting host crops such as Vietnamese winter melon, which the good guys love,” said Daniel.
“Not spraying now has given me the time needed to enjoy the farm rather than work against the odds.”
For more information, the new Apple and Pear IPDM website is now live and contains a wealth of information on identifying and managing pests, including tools, case studies and the opportunity to ‘Ask an expert’.