With mid-August behind us, the crop year has turned full circle. While combines dominate the tillage landscape, some growers are already considering planting for the coming season. The great benefit of early planting – getting work done in good establishment conditions – has certainly been emphasised by the difficulties experienced last year.
But the reaction cannot simply be to plant everything early, as there are also many challenges that emerge from early planting. We cannot forget the higher weed and grass weed pressures that come with early planting, alongside the increased susceptibility to diseases, weeds and pests.
There may be little benefit in solving one problem if it makes another.
I note with interest that Tim O’Donovan of Seedtech has developed an autumn drilling plan for tillage farmers for 2020 to help combat these challenges. The basis of this plan is to plant different crops within different time windows which suit them better.
The challenge is to minimise the risks associated with early planting while having some crops safely established ahead of the busiest part of the autumn planting season.
The plan involves three main start points to sowing windows, finishing with oats.
1 Mid-August to mid-September: the earliest planting option recommends planting winter oilseed rape from the middle of August up to early to mid-September. Planting rape early allows more options for non-inversion planting systems also. Using contractors to either direct drill or strip-drill using deep-leg planters can help to get this crop planted in a timely fashion.
2
Mid-September to mid-October: while many growers have brought forward the planting of winter wheat and winter barley to mid-September, this timing represents a significant risk of BYDV infection and grass weed infestation. Even if there are chemical solutions for BYDV and weeds, early planting adds considerably to the risk and cost.
One alternative option for this time slot is the planting of winter hybrid rye from the third week of September up to mid-October. Hybrid rye seems to be able to cope much better with the challenges of mid-September planting, as it carries a lower risk of BYDV problems. And its tall canopy and smothering ability act to naturally suppress weed growth.
While hybrid rye may be a good crop option for very early planting, Tim O’Donovan emphasises the need to secure a market before planting the crop. Possible markets for rye include animal feed (mainly pigs), milling for bread-making and for the distilling industry.
3
Fourth week of September into November: pushing well into September, the Seedtech autumn-drilling plan recommends winter barley after the third week of September. While this timing still represents a considerable risk of BYDV, Seedtech has a new BYDV tolerant variety available this year called KWS Joyau. This is the first variety that can tolerate this disease and it is likely to be a useful option.
Varieties such as this will make a big difference to early planting decisions, especially where we encounter increased difficulty controlling aphids.
As we get to the end of the month planting of other barley and wheat varieties will get under way.
As the season slips into October, overall BYDV risk levels should be lower but they are not zero.
The yellow leaves of BYDV are often commonplace on cereals but hopefully the new suction towers being put in place by Teagasc will provide more accurate guidance on the need for aphicide application.
However, with falling temperatures and slower emergence, later infections can be more easily controlled by single-standard pyrethroid sprays applied at the recommended times.
Recent developments that will help control BYDV
With regard to BYDV monitoring, it should be noted that a number of new suction towers are being constructed by Teagasc.
The plan is to have three towers in place as part of an aphid trap network. They are 12m high and each suction tower has a sampling radius of 50km.
The sample collection carousel in the suction tower at Oak Park.
The traps collect aphids, plus whatever else is flying at the time. The specimens are loaded into a sample bottle in the trap and these are later taken to the laboratory for analysis. They can be collected on a daily or a weekly basis.
In the lab, the different species are identified under a microscope and molecular diagnosis is used to test for the presence of the virus.
One of these towers is already operational at Oak Park while the other two are under construction, one in west Dublin and the other in Castlemartyr in Cork.
Growers will be aware that there was no real risk assessment for BYDV up to now. Risk was projected relative to planting date and advice on the need for insecticide application was based on this.
Additional benefit comes when these aphids are identified by species and then tested for the presence of virus infection
The general risk from aphids and BYDV infection is related to aphid movement, specifically aphids in flight. The ability to monitor this movement of aphids in flight adds considerably to risk assessment.
Additional benefit comes when these aphids are identified by species and then tested for the presence of virus infection. Even very small aphid numbers can bring infection to a field so knowing whether or not they are carrying virus adds greatly to the decision to spray or not. If a flying aphid is not carrying the virus BYDV then it cannot infect the crop.
KWS Joyau
This is a new high-yielding conventional six-row variety. It has only been in official trials for one year where it produced a very credible 121 as its relative yield, compared to 105 for Quadra and 97 for Cassia.
It appears to have quite good lodging resistance, is early maturing, has good rhyncho resistance but is moderately susceptible to mildew. It also has high KPH, at least in the 2019 trials.
The main reason why there is interest in this variety is its tolerance of BYDV. This is a genetic trait based on tolerance rather than resistance. The variety can show BYDV symptoms, but this does not appear to affect its yield performance.
Its performance in 2019, which was a high BYDV infection year, would indicate that neither yield nor quality were adversely affected, assuming that it had symptoms of the disease.
The tolerance does not reduce aphid numbers and it still may require an insecticide if numbers get very high, which is generally a different issue to BYDV transfer.
The tolerance lasts all through the growing season and it will be particularly useful in mild winters, with early sowing, and in areas that have high risk every year. It is also very useful for situations where spraying may be curtailed. And, of course, it would be particularly useful where one is dealing with resistant aphids.
Consider oilseed rape to get some crops drilled early
The biggest challenge to optimum planting date is that harvesting is taking place in the same time window
One of the big benefits of oilseed rape is its early planting date – from mid-August to early to mid-September, depending on location. This means work done for those with a lot of planting to do.
The biggest challenge to optimum planting date is that harvesting is taking place in the same time window. Sometimes a few damp days can provide the planting opportunity, providing straw is not in the way. This is why winter barley is the best lead-in crop for rape. Where rape is to follow a later harvested crop, there is a lot to be said for chopping the straw to speed up planting.
Another big benefit of oilseed rape is that the crop can utilise reasonable quantities of organic manure. While it takes additional organisation to get manure organised and spread, it is still an ideal slot to get quantities of high-N manures applied in a winter-crop rotation.
High N manures, such as poultry litter or pig slurry, are well suited to oilseed rape because the crop can utilise the bulk of the applied nutrients and so minimise the risk of losses.
Good autumn vegetation also helps to prevent pigeon grazing
It also suits because the nitrogen utilised by the crop to drive autumn canopy growth is vegetation that does not have to be produced again in springtime. And with canopy management used as a guide to nitrogen rate and timing, there can be considerable scope to decrease spring nitrogen application. Good autumn vegetation also helps to prevent pigeon grazing.
TuYV
While oilseed rape brings the advantages of being a good break crop, is suited to organic fertiliser application, and it spreads the workload, it has been very prone to annual yield variability.
Some years ago, researchers in the UK identified Turnip Yellows Virus (TuYV) as being one cause of this yield variability.
But there was no real practical solution.
The disease is transmitted by a few aphid species during autumn, but the peach potato aphid (Myzus persicae) is considered to be the main vector. Crops are most at risk in mild autumns, which also favour aphids. The disease is said to cause yield losses of up to 25%, as well as reducing oil content.
But, now, genetic resistance is available to this disease in a few new varieties.
While these are not yet on the recommended list, limited seed is available for planting this back-end.
We are relatively unfamiliar with this disease in this country, but we do see the symptoms.
If the virus is even partly responsible for annual yield variability, this resistance could help to make the crop more consistent from year to year
It is most visible on the leaves and might often be described as nutrient and, specifically, phosphorus deficiency. This is because early interveinal yellowing progresses to a reddish or purple colour.
TuYV resistance could prove to be an important development in winter oilseed rape husbandry. If the virus is even partly responsible for annual yield variability, this resistance could help to make the crop more consistent from year to year.
The three varieties that we are currently aware of are, Ambassador, Artemis, and Aurelia – all bred by Limagrain.
All three were in recommended list trials last year for the first time and they produced relative yields of 113, 114 and 112, respectively, relative to the control varieties.
While they have yet to be proven across a number of years, it seem that all three also performed very well in 2020, adding to their value.
The resistant varieties
Ambassador has good early-season vigour, is early to flower, has good phoma and pod shatter resistance, has excellent lodging resistance and is of medium canopy height. It is moderately susceptible to light leaf spot.
Artemis shows somewhat less growth vigour in its early life, is very early to flower, has good phoma and pod shatter resistance, has good lodging resistance and is of medium canopy height. It is susceptible to light leaf spot.
Aurelia has high disease resistance ratings for light leaf spot and stem canker and good pod shatter resistance. It has very good early season vigour, is medium-early to flower, has good lodging resistance and a medium height canopy.
Early drilling needs to be planned, with specific crops targeted at separate dates to help minimise the risks.Winter oilseed rape offers a safe early planting opportunity and the crop has enjoyed reasonable prices in recent years.The monitoring of BYDV risk will be greatly helped by a new aphid trap network operated by Teagasc and also the arrival of a BYDV-tolerant winter barley variety.New oilseed rape varieties with resistance to TuYV should help to stabilise yields in this crop.
With mid-August behind us, the crop year has turned full circle. While combines dominate the tillage landscape, some growers are already considering planting for the coming season. The great benefit of early planting – getting work done in good establishment conditions – has certainly been emphasised by the difficulties experienced last year.
But the reaction cannot simply be to plant everything early, as there are also many challenges that emerge from early planting. We cannot forget the higher weed and grass weed pressures that come with early planting, alongside the increased susceptibility to diseases, weeds and pests.
There may be little benefit in solving one problem if it makes another.
I note with interest that Tim O’Donovan of Seedtech has developed an autumn drilling plan for tillage farmers for 2020 to help combat these challenges. The basis of this plan is to plant different crops within different time windows which suit them better.
The challenge is to minimise the risks associated with early planting while having some crops safely established ahead of the busiest part of the autumn planting season.
The plan involves three main start points to sowing windows, finishing with oats.
1 Mid-August to mid-September: the earliest planting option recommends planting winter oilseed rape from the middle of August up to early to mid-September. Planting rape early allows more options for non-inversion planting systems also. Using contractors to either direct drill or strip-drill using deep-leg planters can help to get this crop planted in a timely fashion.
2
Mid-September to mid-October: while many growers have brought forward the planting of winter wheat and winter barley to mid-September, this timing represents a significant risk of BYDV infection and grass weed infestation. Even if there are chemical solutions for BYDV and weeds, early planting adds considerably to the risk and cost.
One alternative option for this time slot is the planting of winter hybrid rye from the third week of September up to mid-October. Hybrid rye seems to be able to cope much better with the challenges of mid-September planting, as it carries a lower risk of BYDV problems. And its tall canopy and smothering ability act to naturally suppress weed growth.
While hybrid rye may be a good crop option for very early planting, Tim O’Donovan emphasises the need to secure a market before planting the crop. Possible markets for rye include animal feed (mainly pigs), milling for bread-making and for the distilling industry.
3
Fourth week of September into November: pushing well into September, the Seedtech autumn-drilling plan recommends winter barley after the third week of September. While this timing still represents a considerable risk of BYDV, Seedtech has a new BYDV tolerant variety available this year called KWS Joyau. This is the first variety that can tolerate this disease and it is likely to be a useful option.
Varieties such as this will make a big difference to early planting decisions, especially where we encounter increased difficulty controlling aphids.
As we get to the end of the month planting of other barley and wheat varieties will get under way.
As the season slips into October, overall BYDV risk levels should be lower but they are not zero.
The yellow leaves of BYDV are often commonplace on cereals but hopefully the new suction towers being put in place by Teagasc will provide more accurate guidance on the need for aphicide application.
However, with falling temperatures and slower emergence, later infections can be more easily controlled by single-standard pyrethroid sprays applied at the recommended times.
Recent developments that will help control BYDV
With regard to BYDV monitoring, it should be noted that a number of new suction towers are being constructed by Teagasc.
The plan is to have three towers in place as part of an aphid trap network. They are 12m high and each suction tower has a sampling radius of 50km.
The sample collection carousel in the suction tower at Oak Park.
The traps collect aphids, plus whatever else is flying at the time. The specimens are loaded into a sample bottle in the trap and these are later taken to the laboratory for analysis. They can be collected on a daily or a weekly basis.
In the lab, the different species are identified under a microscope and molecular diagnosis is used to test for the presence of the virus.
One of these towers is already operational at Oak Park while the other two are under construction, one in west Dublin and the other in Castlemartyr in Cork.
Growers will be aware that there was no real risk assessment for BYDV up to now. Risk was projected relative to planting date and advice on the need for insecticide application was based on this.
Additional benefit comes when these aphids are identified by species and then tested for the presence of virus infection
The general risk from aphids and BYDV infection is related to aphid movement, specifically aphids in flight. The ability to monitor this movement of aphids in flight adds considerably to risk assessment.
Additional benefit comes when these aphids are identified by species and then tested for the presence of virus infection. Even very small aphid numbers can bring infection to a field so knowing whether or not they are carrying virus adds greatly to the decision to spray or not. If a flying aphid is not carrying the virus BYDV then it cannot infect the crop.
KWS Joyau
This is a new high-yielding conventional six-row variety. It has only been in official trials for one year where it produced a very credible 121 as its relative yield, compared to 105 for Quadra and 97 for Cassia.
It appears to have quite good lodging resistance, is early maturing, has good rhyncho resistance but is moderately susceptible to mildew. It also has high KPH, at least in the 2019 trials.
The main reason why there is interest in this variety is its tolerance of BYDV. This is a genetic trait based on tolerance rather than resistance. The variety can show BYDV symptoms, but this does not appear to affect its yield performance.
Its performance in 2019, which was a high BYDV infection year, would indicate that neither yield nor quality were adversely affected, assuming that it had symptoms of the disease.
The tolerance does not reduce aphid numbers and it still may require an insecticide if numbers get very high, which is generally a different issue to BYDV transfer.
The tolerance lasts all through the growing season and it will be particularly useful in mild winters, with early sowing, and in areas that have high risk every year. It is also very useful for situations where spraying may be curtailed. And, of course, it would be particularly useful where one is dealing with resistant aphids.
Consider oilseed rape to get some crops drilled early
The biggest challenge to optimum planting date is that harvesting is taking place in the same time window
One of the big benefits of oilseed rape is its early planting date – from mid-August to early to mid-September, depending on location. This means work done for those with a lot of planting to do.
The biggest challenge to optimum planting date is that harvesting is taking place in the same time window. Sometimes a few damp days can provide the planting opportunity, providing straw is not in the way. This is why winter barley is the best lead-in crop for rape. Where rape is to follow a later harvested crop, there is a lot to be said for chopping the straw to speed up planting.
Another big benefit of oilseed rape is that the crop can utilise reasonable quantities of organic manure. While it takes additional organisation to get manure organised and spread, it is still an ideal slot to get quantities of high-N manures applied in a winter-crop rotation.
High N manures, such as poultry litter or pig slurry, are well suited to oilseed rape because the crop can utilise the bulk of the applied nutrients and so minimise the risk of losses.
Good autumn vegetation also helps to prevent pigeon grazing
It also suits because the nitrogen utilised by the crop to drive autumn canopy growth is vegetation that does not have to be produced again in springtime. And with canopy management used as a guide to nitrogen rate and timing, there can be considerable scope to decrease spring nitrogen application. Good autumn vegetation also helps to prevent pigeon grazing.
TuYV
While oilseed rape brings the advantages of being a good break crop, is suited to organic fertiliser application, and it spreads the workload, it has been very prone to annual yield variability.
Some years ago, researchers in the UK identified Turnip Yellows Virus (TuYV) as being one cause of this yield variability.
But there was no real practical solution.
The disease is transmitted by a few aphid species during autumn, but the peach potato aphid (Myzus persicae) is considered to be the main vector. Crops are most at risk in mild autumns, which also favour aphids. The disease is said to cause yield losses of up to 25%, as well as reducing oil content.
But, now, genetic resistance is available to this disease in a few new varieties.
While these are not yet on the recommended list, limited seed is available for planting this back-end.
We are relatively unfamiliar with this disease in this country, but we do see the symptoms.
If the virus is even partly responsible for annual yield variability, this resistance could help to make the crop more consistent from year to year
It is most visible on the leaves and might often be described as nutrient and, specifically, phosphorus deficiency. This is because early interveinal yellowing progresses to a reddish or purple colour.
TuYV resistance could prove to be an important development in winter oilseed rape husbandry. If the virus is even partly responsible for annual yield variability, this resistance could help to make the crop more consistent from year to year.
The three varieties that we are currently aware of are, Ambassador, Artemis, and Aurelia – all bred by Limagrain.
All three were in recommended list trials last year for the first time and they produced relative yields of 113, 114 and 112, respectively, relative to the control varieties.
While they have yet to be proven across a number of years, it seem that all three also performed very well in 2020, adding to their value.
The resistant varieties
Ambassador has good early-season vigour, is early to flower, has good phoma and pod shatter resistance, has excellent lodging resistance and is of medium canopy height. It is moderately susceptible to light leaf spot.
Artemis shows somewhat less growth vigour in its early life, is very early to flower, has good phoma and pod shatter resistance, has good lodging resistance and is of medium canopy height. It is susceptible to light leaf spot.
Aurelia has high disease resistance ratings for light leaf spot and stem canker and good pod shatter resistance. It has very good early season vigour, is medium-early to flower, has good lodging resistance and a medium height canopy.
Early drilling needs to be planned, with specific crops targeted at separate dates to help minimise the risks.Winter oilseed rape offers a safe early planting opportunity and the crop has enjoyed reasonable prices in recent years.The monitoring of BYDV risk will be greatly helped by a new aphid trap network operated by Teagasc and also the arrival of a BYDV-tolerant winter barley variety.New oilseed rape varieties with resistance to TuYV should help to stabilise yields in this crop. 
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