Published on 27/09/2022
Take 18 different crop protection treatments. Test them repeatedly on five different forage brassica crops. Compare the results, and draw conclusions, based on sound scientific principles. How much time and effort do you think that will take?
Fortunately, you don’t have to do this, because someone’s already done it for you! That someone is Nicole Morris, Corteva territory manager and technical specialist for pastures and forages. And she had a very good reason.
“A common question we get asked both prior to, and during, the brassica season is: How many active ingredients can we load the spray tank with?”
The motive is understandable, Morris says – growers and contractors want to reduce the number of spray applications they make per crop. Making fewer passes is more efficient and cost effective. But only if it doesn’t result in crop injury, which can occur when heavily loaded tank mixes are applied in hot weather.
So last season Corteva set out to answer the question, particularly as it relates to Corteva insecticides and herbicides.
“We know they’re compatible, because we’ve done the compatibility trials. What we wanted to find out was what happened in terms of crop injury when we loaded the tank.”
The good news? “We’re confident Corteva IPM insecticides are crop-safe when tank mixed with our post-emergence herbicides.”
The trial included multiple plots of five common brassica crops– forage rape, kale, swedes, turnips and Raphno hybrid brassicas – on a dryland Canterbury site that received above average rainfall for the season.
Sown in December, these were treated with trial insecticide/herbicide mixes in January. Plant injury and biomass reduction were then measured across all plots 18 and 55 days after application.
Treatments were focussed around Corteva’s Milestone and Korvetto herbicides, mixed with Gallant Ultra and different insecticides. These included IPM-friendly Sparta and Transform, which are both suspension concentrate (SC) formulations, as well as earlier generation organophosphate (OP) products formulated as emulsifiable concentrates (EC).
Getting specific advice from a Corteva territory sales manager remains the best place for farmers or contractors to start if they’re unsure about tank loading or compatibility, Morris says.
Meantime Corteva is finalising plans for a second round of experiments this summer, aiming to refine the tank mix treatments, extend the trials beyond Canterbury, and hopefully spray on a hot day to duplicate what can happen in real-world commercial crops.
Corteva marketing manager Glen Surgenor says there’s no direct financial gain to the company from such field research; in fact, it’s often expensive and time-consuming. But that’s not the point.
“Forage crops – particularly brassicas – are one of Corteva’s four key markets in New Zealand. We want to be a leader in this category and provide the industry with the best advice and support.”
“Having Nicole able to do this sort of in-depth work on crops which are of major significance to so many NZ livestock farmers is a really important part of achieving that goal, and it’s something we’re happy to continue investing in.”
For more detail talk to your local Corteva Agriscience territory sales manager.