Since the introduction of Flexi-N, ‘leaf scorch’ has slowly become an accepted part of the liquids phenomen with full crop recovery and no yield loss. In recent years however with the advent of new Ag Chemicals, the question has been asked if the same crop recovery principles still apply.

Recent scorch trials conducted at York and Lake Grace have shown higher levels of damage under NDVI assessment and leaf test compared to the control treatment but in all cases recovered well to achieve higher yields at harvest. 

Unfortunately the planned Bunjil site was removed from the project due to the poor season.. We are hoping to redo this trial in the North to assess the impact on crops of some commonly used Ag Chemicals mixed with Flexi-N.

See below for final yield results, note that each treatment was replicated three times for scientific analysis. 

Scorch damage

Scorch resultsFig 1: Top image shows the worst scorch damage at York (Trial B, Trt 15) and bottom image shows scorch recovery in Trial A.

 

1: York Site

Trial A: Z32 application

Kalyx recorded the highest percentage of leaf damage on Treatments 4, 6, 8 & 9, measured at 7DAT. 
Crop had 2-3 nodes when sprayed.

• 0.3 - 0.5 t/ha response to 100 L/ha Flexi-N
• No ill effects on yield from applying Precept, Velocity or Esteron LV with Flexi-N
• Higher yield with Streamers (did not find this Lake Grace)

Table 1

Trial B: Z37 application

Kalyx recorded the highest percentage of leaf damage on Treatment 15, with up to 85% scorch evident on some leaves, measured at 10DAT. 

• 0.5 t/ha response to 100 L/ha Flexi-N without Prosaro
• 0.3 t/ha response to Prosaro
• Small but not significant response to Flexi-N where Prosaro was applied
• 0.5 t/ha reduction in yield from High scorch Brew applied with Flexi-N (scorch impact)
• 0.8 t/ha reduction in yield from Prosaro + Supercharge + CuSO4 applied with Flexi-N (scorch impact)• Flat fan nozzles achieved a +0.3 t/ha better result than streamers 

graph 2 

2. Lake Grace site

Trial A: Z30 application

Kalyx recorded the highest percentage of leaf damage on Treatments 4, 6, 8 & 9, measured at 8DAT. 

• No evidence of scorch reducing yield (Trt 9 caused severe scorch)
• No significant difference between flat fans and streamers

graph 3

Trial B: Z37 application

Kalyx recorded the highest percentage of leaf damage on Treatment 15 with up to 80% scorch evident on some leaves, measured at 9DAT.

• 0.3 t/ha response to Prosaro 
• Inconclusive effects from severe scorch Trts 15 (cf 14) & 16 (cf 12) 
• No significant difference between flat fans and streamers

graph 4

Trial A rates:
• Velocity: 1L/ha with 50L/ha water
• Esteron LV: 1.5L/ha with 50L/ha water 
• Precept: 2L/ha with 50L/ha water 
• High scorch brew: 0.3% of 20L with Flexi-N 

Trial B rates:
• Prosaro: 1L/ha with 50L/ha water 
• SuperCharge: 1% of 20L with Flexi-N 
• CuSO4: 4kg with 20L Flexi-N
• High scorch brew: 0.3% of 20L with Flexi-N
NOTE: Rates were at the higher end of the supplier recommendations to increase chance of scorch.

Overall, yield results from the project did not present any findings that were unexpected and should provide users with the confidence to apply treatments concurrently without needing that extra pass. General scorch precautions still apply including temperature, wind, Delta-t and plant stage.
 
This project would not have been possible without the assistance from Elevo in conducting the NDVI drone flyovers with orthomosaic ratings and Kalyx for providing a Research Agronomist to conduct routine site assessments on the up-close leaf damage – so a big thank you to both of those teams.
 
For more information on this project or interested in learning more about how to prevent scorch when mixing chemicals - please speak to your local CSBP Area Manager.
 
We would also like to thank the growers involved Steve and Anne Chipper at York, and Arthur Slarke in Lake Grace. Their involvement with this project is much appreciated, as without access to their crops, this project would just not be possible.
 
Scott Orrock
By Scott Orrock
- Insights and innovation Specialist

Scott grew up on a family farm East of Kulin then spent 6 years in the Royal Australian Air Force after school, before completing his Masters of Business Administration. He is passionate about the future of agriculture, and how technology will contribute to the industry for better efficiencies. 

Scott started with CSBP in 2016 as the Nitrogen Product Manager and is now working across a range of marketing, insight and innovation projects within the business aimed at challenging traditional practices and to improve the overall customer experience.

Agronomic insights

Want to stay up to date? Have our latest research findings and news delivered to your inbox