home news forum careers events suppliers solutions markets expos directories catalogs resources advertise contacts
 
Solution Page

Solutions
Solutions sources
Topics A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  Species
 

Australia - Break the between-season bridges for pests and diseases 


Australia
January 21, 2016

Destroying the green bridge of weeds and volunteer crops during summer is a key tactic for reducing aphid and virus risks to canola plantings in 2016.

Weeds such as wild radish, wild turnip and marshmallow and volunteer canola plants can host big populations of insects, including aphid vectors for viruses, and should be controlled in the lead-up to sowing.


Dr Paul Umina, of Cesar, with Department of Agriculture and Food WA entomologist Svetlana Micic discuss integrated management for green peach aphid at the GRDC, AHRI and CCDM 2015 Crop Protection Forum, held at the University of Western Australia. PHOTO: Cox Inall Communications 

Dr Paul Umina, of Cesar and The University of Melbourne, said western region growers should particularly monitor infestations of green peach aphids (GPA – Myzus persicae) in coming months, especially after significant rainfall events.

He said GPA contributed to a costly outbreak of Beet western yellows virus (BWYV) in southern Australia in autumn-winter 2014 that significantly reduced canola crop yields.

“GPA is the principal vector of BWYV and typically the most common aphid species that affects seedling canola plants,” he said.

Dr Umina outlined tactics for effective GPA management at the inaugural GRDC-funded Australian Herbicide Resistance Initiative (AHRI) and Centre for Crop and Disease Management (CCDM) 2015 Crop Protection Forum, held late last year at The University of Western Australia.

“Although summer rainfall and mild temperatures into early autumn will primarily drive GPA numbers and associated virus potential, early weed control can help to minimise the risk of aphid populations building-up,” he said.

“Sowing canola into standing stubble will also reduce the risk of early aphid infestations.”

The GRDC Reducing Aphid and Virus Risk GrowNotes ‘Tips and Tactics’ publication outlines a range of paddock management strategies for growers when sowing in conditions of high BWYV risk.

These include using canola seed that is treated with a neonicotinoid insecticide to protect seedlings from early season aphid infestations.

Research conducted by Cesar, in conjunction with Advanta Seeds, has found all registered seed dressings for GPA provided good control of these aphids for up to eight weeks, in semi-field conditions, and had similar efficacy to each other.

Dr Umina said GPA has a high propensity to develop resistance to insecticides and it was vital to ensure correct identification of this species before considering in-crop insecticide control measures.

He said insecticide resistance testing funded by GRDC found GPA populations with high levels of resistance to carbamates (such as primicarb) and pyrethroids (such as bifenthrin and alpha-cypermethrin) were common across Australia.

“Many populations of GPA have also been found with moderate resistance to organophosphates (such as dimethoate and chlorpyifos),” he said.

“Unlike for some other crop insect pests, insecticide resistance in GPA populations has been fast to develop.”

Dr Umina recommended western region growers consider using sulfoxaflor in canola (before crop closure) if GPA numbers reached threshold levels and there were resistance concerns with other insecticides.

“But any insecticide use should be carried out as part of a broader integrated resistance management plan and with consideration to bee protection,” he said.

“Careful management of GPA is required to ensure the effectiveness and longevity of the insecticide options that we have available to us.

“This includes close monitoring of canola crop seedlings, only using insecticides if absolutely necessary, rotating chemical modes of action within and between seasons and considering biological control measures.”

For more information, GRDC’s Resistance management strategy for green peach aphid (GPA) in Australian Grains can be found at: www.ipmguidelinesforgrains.com.au/ipm-information/resistance-management-strategies/.

There is a GRDC Crop Aphids Back Pocket Guide to help identify aphids that can be found at: www.grdc.com.au/CropAphidsBackPocketGuide and the GRDC GrowNotes Reducing Aphid and Virus Risk ‘Tips and Tactics’ resource can be found at: www.grdc.com.au/GRDC-TT-ReducingAphidVirus.

 



More solutions from: GRDC (Grains Research & Development Corporation)


Website: http://www.grdc.com.au

Published: January 21, 2016


Copyright @ 1992-2024 SeedQuest - All rights reserved