Article taken from Tillage Magazine
Oilseed rape yields on farm have barely increased over the past quarter century and currently average just over 3t/ha. However, the crop can produce well over double that in trials and is theoretically capable of yielding over 10t/ha, says Agrovista technical manager Chris Martin.
He believes poor establishment is one of the key reasons why the crop is not achieving anywhere near it’s potential. “There are a lot of agronomic improvements that could be made, but better establishment could cover a lot of the yield gap.
Optimum canopy
“By getting the right plant population from the outset we stand a much better chance of achieving the optimum canopy toward the end of flowering, which is the crucial period when seed is set.”
He speaks for a wealth of experience. OSR establishment has been at the heart of Agrovista’s Growcrop Gold trials carried out over a range of sites across the UK over the past 6 years.
“Highest yields have tended to be achieved with lower seed rates on good seedbeds with adequate moisture, giving evenly established low plant populations in the autumn,” Says Mr Martin.
Growers need to think in terms of seeds per row, rather than seeds/m2, especially as they move to wider rows, he explains.
Precision drilling
“We have seen some massive differences over the years, the most dramatic being when we started out looking at a little precision plot drill 10 years ago. We achieved 0.5t/ha extra yield in that first season over any other establishment technique.
“We’ve continued to go down this precision-sowing route while removing compaction to ensure there are no restrictions to root development, allowing season-long moisture and nutrient availability. It’s where we need to be to get to the next level.”
This is particularly the case with wide-row crops, where competition between OSR plants in the same row appears to be more important than between rows, Mr Martin points out.
“We now know from our Growcrop Gold results that the highest yields have typically been achieved sowing 15-20 seeds per m of row to produce 12-15 plants.”
Lower seed rates have achieved higher yields in trial, but are not robust enough for practical situations, he adds.
In row competition
“More than 12-plants tends to create too much early competition – plants fight for light and this reduces establishment and remaining plants can tend to grow tall and spindly. We want to encourage a more natural prostrate plant structure that branches from the bottom.”
As a rule of thumb, 40-60 seeds/m2 is fine for conventional drilling at 12.5-25cm spacing where normal establishment is expected. But at 50cm row spacing, 60 seeds/m2 would result in 30 seeds/m of row length, twice the number actually required, he notes.
“Growers should decrease seed rates when they move to wide rows.” Says Mr Martin. “But some actually raise the rate when sub casting to compensate for the fact that seeds are going in behind a leg, which results in variable depth and establishment.”
Growcrop Gold trials have been examining how to combat this, by removing compaction and using more accurate drilling techniques to maximise establishment, removing the temptation to cram plats into the row.
A range of drills have and continue to be examined to show what can be achieved through realistic germination and establishment, ensuring, as near as possible that every seed grows. It’s not the only plant canopies that benefit growers’ pockets will too, says Mr Martin.
“As plant breeding Improves, more traits will be introduced into seeds, which will become more expensive. Seed dressings will cost more too, so we need to create the perfect environment to every seed to give confidence to cut rates.”
Results to date show there is often no significant difference between drills tested so far, provided steps are taken to alleviate any compaction where needed.
Oilseed rape yields on farm have barely increased over the past quarter century and currently average just over 3t/ha. However, the crop can produce well over double that in trials and is theoretically capable of yielding over 10t/ha, says Agrovista technical manager Chris Martin.
He believes poor establishment is one of the key reasons why the crop is not achieving anywhere near it’s potential. “There are a lot of agronomic improvements that could be made, but better establishment could cover a lot of the yield gap.
Optimum canopy
“By getting the right plant population from the outset we stand a much better chance of achieving the optimum canopy toward the end of flowering, which is the crucial period when seed is set.”
He speaks for a wealth of experience. OSR establishment has been at the heart of Agrovista’s Growcrop Gold trials carried out over a range of sites across the UK over the past 6 years.
“Highest yields have tended to be achieved with lower seed rates on good seedbeds with adequate moisture, giving evenly established low plant populations in the autumn,” Says Mr Martin.
Growers need to think in terms of seeds per row, rather than seeds/m2, especially as they move to wider rows, he explains.
Precision drilling
“We have seen some massive differences over the years, the most dramatic being when we started out looking at a little precision plot drill 10 years ago. We achieved 0.5t/ha extra yield in that first season over any other establishment technique.
“We’ve continued to go down this precision-sowing route while removing compaction to ensure there are no restrictions to root development, allowing season-long moisture and nutrient availability. It’s where we need to be to get to the next level.”
This is particularly the case with wide-row crops, where competition between OSR plants in the same row appears to be more important than between rows, Mr Martin points out.
“We now know from our Growcrop Gold results that the highest yields have typically been achieved sowing 15-20 seeds per m of row to produce 12-15 plants.”
Lower seed rates have achieved higher yields in trial, but are not robust enough for practical situations, he adds.
In row competition
“More than 12-plants tends to create too much early competition – plants fight for light and this reduces establishment and remaining plants can tend to grow tall and spindly. We want to encourage a more natural prostrate plant structure that branches from the bottom.”
As a rule of thumb, 40-60 seeds/m2 is fine for conventional drilling at 12.5-25cm spacing where normal establishment is expected. But at 50cm row spacing, 60 seeds/m2 would result in 30 seeds/m of row length, twice the number actually required, he notes.
“Growers should decrease seed rates when they move to wide rows.” Says Mr Martin. “But some actually raise the rate when sub casting to compensate for the fact that seeds are going in behind a leg, which results in variable depth and establishment.”
Growcrop Gold trials have been examining how to combat this, by removing compaction and using more accurate drilling techniques to maximise establishment, removing the temptation to cram plats into the row.
A range of drills have and continue to be examined to show what can be achieved through realistic germination and establishment, ensuring, as near as possible that every seed grows. It’s not the only plant canopies that benefit growers’ pockets will too, says Mr Martin.
“As plant breeding Improves, more traits will be introduced into seeds, which will become more expensive. Seed dressings will cost more too, so we need to create the perfect environment to every seed to give confidence to cut rates.”
Results to date show there is often no significant difference between drills tested so far, provided steps are taken to alleviate any compaction where needed.