Hands on demonstrations and discussion about the regulatory and agronomic considerations of effective spray applications were features of the recent spray application workshops held across western Victoria.
Funded by the Grains Research and Development Corporation (GRDC) and coordinated by the Birchip Cropping Group (BCG), the events were held in St. Arnaud, Pyramid Hill, Manangatang and Robinvale.
“Attendance numbers exceeded expectations with more than 180 growers, spray contractors, advisors and machinery specialists coming along” said BCG’s Ciara Cullen who coordinated the workshops and organised an extra workshop in St. Arnaud to cater to demand.
“Growers and commercial sprayer operators wanted to learn about the new 2,4-D application requirements that came in to effect recently to ensure they comply with new legislation” she said.
On 4 October 2018, the Australian Pesticides and Veterinary Medicines Authority (APVMA) suspended all product labels containing the active ingredient 2,4-D and replaced it with a permit. Permits now require these products to be applied with a Very Coarse (VC) spray quality or VC or Extra Coarse (EC) spray quality in sensitive areas. The permit will be effective until 15 April 2019.
With nearly 240 products registered 2,4-D as an active constituent and summer weed control just around the corner, sprayer operators were urged to demonstrate responsible use.
One Manangatang workshop attendee said “do the right thing and we won’t lose valuable chemistry”.
Content was developed and presented by respected industry expert Bill Gordon, Bill Gordon Consulting. He cautioned growers to make accurate nozzle selection in the summer weed control period and encouraged them to be proactive and order their nozzles early to ensure they are ready to go for summer fallow weed control.
Mr Gordon also discussed the key principles of spray application including, nozzle choice, water quality and rates, application speed, boom height and watching and understanding weather patterns as the move to coarser droplet size presents challenges in weed control efficacy.
The number of droplets produced may be reduced if the total application volume isn’t increased. Also, much larger droplets may not stay on certain waxy weed leaf surfaces or ‘bounce’ off the leaf surface.
Mr Gordon said using robust rates at label instructions was essential to getting the best coverage possible. At least 70L/ha of water was recommended in low stubble environments and at 80L/ha as stubble loads increase.
GRDC have developed a factsheet “Maintaining efficacy with larger droplets – New 2,4-D Application Requirements” in conjunction with Bill Gordon which is available via their website.
For more information about the GRDC spray application project including future events, contact the BCG office on 03 5492 2787.
