Figure 1: An example of crop phytotoxicity caused by incorrect spraying procedure. (Source: SACOA)
Correct application timing is critical to maximise the performance of most crop protection products, particularly for selective herbicides, preventative fungicides and foliar nutrients. Large programs and weather challenges often require the application of multiple products in a single pass, which can result in compromised product activity or crop safety.
Using correct mixing and application practice – right spray quality (usually means switching nozzle type from summer spraying), correct water volumes, avoid overlaps and ensuring boomspray is correctly calibrated.
Ensuring thorough tank cleaning between differing actives/crops.
Selecting the correct adjuvant based on mode of action of most important active.
Being aware of crop/weed stresses, such as water logging/droughting/frosting/soil disease, which may slow growth resulting in more crop damage and/or reduced weed control.
Throughout 2014 SACOA contracted a large number of independent field trials aimed at;
Products evaluated included;
A range of broadleaf and grass selective herbicides with mineral oil, methylated seed oil and soy lecithin adjuvants were evaluated in tank mixtures with liquid UAN, fungicide, compatibilisers and micro nutrients. Herbicides evaluated included Crusader®, Velocity®, Precept®, MCPA, 2,4D, Metribuzin, Intervix®, Axial®, Topik® and Monza®.
Results showed ENHANCE® proved equivalent to Uptake® in terms of crop safety, even in tank mixtures with liquid UAN, auxin-type herbicides and fungicides. PLANTOCROP® proved equivalent to other methylated seed oils in Monza®, Topik® and Axial® mixes. Crop phyto effects observed were generally transient with no impact on yield. The tank mix compatibiliser N-Flow® was found to be safe to apply in-crop.
Figure 2 : Cereal stage at application Gnowangerup (GS 13) & Walkaway site (GS 21-25) 18.6.14 (Source: SACOA)
Chart 1: Crop effect of common cereal herbicide mixtures measured as biomass reduction and leaf discolouration relative to the untreated. Average of 7 sites – Walkaway, Moora, Yorkrakine, Quairading, Gnowangerup (BT Parkin) and Quambatook – 2 sites(Agrivision). *Intervix® treatments applied to Scope barley. July 2014.
In this series of independently conducted canola trials across the Victorian Mallee, mid north of South Australia and Western Australia – a range of adjuvants were trialled in the triazine tolerant canola system in mixtures with atrazine, propyzamide, clethodim and quazilofop ethyl. The most efficacious treatments on annual ryegrass were the three-way mixes of atrazine + clethodim + quizalofop ethyl which were also the highest yielding. Propyzamide caused a significant amount of crop damage when applied early post emergent.
Trials comparing the efficacy and crop safety of methylated seed oils found PLANTOCROP® to be equivalent to Hasten®, with no difference in crop safety, weed control or final yield.
Figure 3: Gnowangerup TT Canola Atrazine + Clethodim + Quazalifop-Ethyl + Hasten 11DAA 25/06/14. White necrotic spots indicate dessication from rapid penetration with methylated seed oil.
Chart 2: Crop effect, ryegrass efficacy and yield of common canola herbicide mixtures measured as biomass reduction and leaf discolouration relative to the untreated. Average of 4 sites – Gnowangerup (SACOA) Saddleworth (AW Vater), York (ADAMA) and Mallee (Agrivision). July 2014 – Yield LSD: 0.118 @95%
Chart 3: Crop effect, ryegrass efficacy and yield of GRP A and Atrazine mixtures with methylated seed oils. Source: ADAMA/SACOA joint trial York WA. July 2014 – Yield LSD: 0.118 @95%
SACOA are continuing to invest in research to provide agronomic solutions in broadacre cropping in 2015. Work currently underway includes;
Disclaimer and Copyright
This document should act as a guide only and no purchase or usage decisions should be made based on the information provided without obtaining independent, expert advice. SACOA and contributors do not necessarily recommend or endorse any products or manufacturers referred to. SACOA Pty Ltd will not be liable for any loss, damage, cost or expense incurred or arising by reason of any person using or relying on the information contained in this document. More information is available from SACOA via sacoa.com.au or 08 9386 7666, or by contacting your local reseller.
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