By Laura Thomas
As olive crops begin to ripen across parts of the country, Australian growers would be looking to complete their weed, pest and disease control efforts well before harvest.
Troublesome weeds will always present a management issue for growers, while key diseases like olive anthracnose and Australian insect pest olive lace bug, have the potential to devastate a grove if not effectively managed.
It is widely understood that a healthy tree, is a happy one.
And while an integrated pest and disease management best practice approach is always recommended, most growers use some form of chemical application to help stop the spread.
So it’s important you ensure the chemicals you use are approved for use on olive trees and understand any withholding periods that may apply.
Fortunately, a range of Agricultural Pesticides and Veterinary Medicines Authority (APVMA) approved herbicide and pesticide options are available for use by olive growers, to help keep weeds, disease and bugs at bay.
Olive lace bug
Most Australian olive growers would be familiar with the ongoing threat of olive lace bug, Froggattia olivinia, the nation’s number one olive pest.
The dreaded sap-sucking insect feeds from the leaves of its host, stripping its branches of leaves and causing branch die-back.
The pest is found in all olive-growing parts of the country, including Tasmania.
New infestations can occur regularly throughout the growing season, so it’s important to remain vigilant, know what the early signs are and ensure infected trees are treated quickly to stop the spread.
Olive lace bug thrives in warm, moist conditions. And while South Australia is still in the throes of a hot, dry spell, the threat of infestation remains for many growers in areas of New South Wales and Queensland, where the landscape is still green and wet.
So what should you do?
Knowledge is power. Know how to spot an outbreak and get onto it early.
This detailed tutorial by Dr Robert Spooner Hart, an Associate Professor at the University of Western Sydney, is available on the OliveBiz website. It provides images and information to help you identify and treat an outbreak.
Chemical selection
The Australian Government’s agvet chemical regulator, the APVMA, has approved a range of chemicals for use on olive trees.
A full list can be found on their online permit register, here.
Dr Spooner-Hart and plant pathologist Dr Len Tesoriero have also carried out extensive research into the efficacy of pesticides for use on key Australian olive pests, such as olive lace bug.
A detailed overview of key chemicals can be found in their report, Evaluation of Key Chemicals for Pest Management in the Olive Industry, available on the OliveBiz website.
It is important to thoroughly read the label of all insecticides and herbicides used in your grove and to ensure any withholding period requirements are met prior to harvest.
What is a withholding period and why does it matter?
This is the minimum amount of time that must pass between the application of a chemical in the grove and harvest of the fruit.
This timeframe is set by the APVMA to ensure chemical residue in the olives does not exceed maximum allowable levels.
More information is available via the APVMA website.
More information:
Information regarding olive integrated pest and disease management best practice is available for members on the Australian Olive Association website.
AOA members can also refer to the resources available from the Members Lounge at http://www.australianolives.com.au.
Not a member? Find out more about the benefits of joining the industry’s national representative body at http://www.australianolives.com.au/membership-benefits/.
