Article taken from the Anglia Farmer
Early canopy management in this season’s forward oilseed rape crops could save growers hundreds of pounds a hectare, suggests new research assessing the impact of lodging on yields.
Lodging remains widespread and could be costing growers much more than previously thought, says Sarah Kendall of ADAS. Losses can top £500/ha at current market values in severely lodged areas, and almost half that even where crops are only leaning.
Artificial lodging experiments carried out by ADAS and funded by BASF were conducted last season in the variety Kite at four growth stages – early and mid-flowering and early and mid-seed fill. Three lodgings angles were assessed: 90°, 45° and 22.5°.
Flat crops suffered the most damage. Yields of the 4.5t/ha, the latter at mid-seed Oil contents dropped by up to 6%.
More surprisingly, 22.5° crops that were only leaning during seed fill were also hit hard. “Such leaning is sometimes regarded as beneficial, helping to avoid shattering and making combining easier,” says Dr Kendall. “However, our findings show that yield can be cut by 25%.
Two aerial surveys, one in East Anglia during 2012 and the other last year in North Yorkshire, Lincolnshire and Cambridgeshire, reveal how common such losses are. They showed respectively that 99% and 100% of fields were affected by lodging, with an average 31% of crop area lodged.
Based on an OSR price of £250/t and that amount of lodging, a flat crop could cost growers £170/ha in lost yield and oil content alone, before additional combining and drying costs are accounted for. “Even late leaning can have dramatic effects, leading to a potential loss of £70/ha.”
This year’s forward crops will need careful management to avoid lodging and an overthick canopy that reflects a lot of light, reducing yield potential. Thinner crops – where about 10% soil is visible looking down from above during flowering – could fare better.
That equates to a canopy with a Green Area Index (GAI) of about 3.5, which allows sunlight to penetrate down to the leaves, the biggest contributors to yield. Crops with a GAI above 0.8 will require a growth regulator such as Caryx or Sunorg Pro/Caramba.
Agrovista technical manager Mark Hemmant favours Caryx at stem extension. “Most crops look like they will need active intervention in 2015 to prevent disappointing yields – and Caryx delivers additional yield even in the absence of lodging.
Work at Agrovista’s Morley Growcrop Gold site in 2013 showed a crop of low seed rate/wide row Quartz treated with 1 litre/ha of Caryx produced an additional 0.3t/ha over untreated, reflecting similar results on other sites.
Early canopy management in this season’s forward oilseed rape crops could save growers hundreds of pounds a hectare, suggests new research assessing the impact of lodging on yields.
Lodging remains widespread and could be costing growers much more than previously thought, says Sarah Kendall of ADAS. Losses can top £500/ha at current market values in severely lodged areas, and almost half that even where crops are only leaning.
Artificial lodging experiments carried out by ADAS and funded by BASF were conducted last season in the variety Kite at four growth stages – early and mid-flowering and early and mid-seed fill. Three lodgings angles were assessed: 90°, 45° and 22.5°.
Flat crops suffered the most damage. Yields of the 4.5t/ha, the latter at mid-seed Oil contents dropped by up to 6%.
More surprisingly, 22.5° crops that were only leaning during seed fill were also hit hard. “Such leaning is sometimes regarded as beneficial, helping to avoid shattering and making combining easier,” says Dr Kendall. “However, our findings show that yield can be cut by 25%.
Two aerial surveys, one in East Anglia during 2012 and the other last year in North Yorkshire, Lincolnshire and Cambridgeshire, reveal how common such losses are. They showed respectively that 99% and 100% of fields were affected by lodging, with an average 31% of crop area lodged.
Based on an OSR price of £250/t and that amount of lodging, a flat crop could cost growers £170/ha in lost yield and oil content alone, before additional combining and drying costs are accounted for. “Even late leaning can have dramatic effects, leading to a potential loss of £70/ha.”
This year’s forward crops will need careful management to avoid lodging and an overthick canopy that reflects a lot of light, reducing yield potential. Thinner crops – where about 10% soil is visible looking down from above during flowering – could fare better.
That equates to a canopy with a Green Area Index (GAI) of about 3.5, which allows sunlight to penetrate down to the leaves, the biggest contributors to yield. Crops with a GAI above 0.8 will require a growth regulator such as Caryx or Sunorg Pro/Caramba.
Agrovista technical manager Mark Hemmant favours Caryx at stem extension. “Most crops look like they will need active intervention in 2015 to prevent disappointing yields – and Caryx delivers additional yield even in the absence of lodging.
Work at Agrovista’s Morley Growcrop Gold site in 2013 showed a crop of low seed rate/wide row Quartz treated with 1 litre/ha of Caryx produced an additional 0.3t/ha over untreated, reflecting similar results on other sites.