Farmers planning to get back into oilseed rape growing this autumn on the back of sustained high commodity prices should invest in husbandry from the off to ensure maximum return – with pre-emergence weed control strongly advised to ensure crops get away well.
That’s the advice from Agrii agronomist Simon Gould, who points out that the challenges – such as moisture conservation and seed-soil contact – involved in getting OSR established and away quickly to beat the threat of slugs and pigeons mean the importance of a strong weed control foundation is something growers can be tempted to put less emphasis on, according to whether they think the crop will make it strongly through its critical early stages.
“Even if the weather is warm and dry into the autumn, aiding crop growth, such conditions also mean later-applied residual grassweed herbicides may not work as well as expected,” he notes.
“Early broadleaf weed control in OSR is not so much of an issue, as there are effective options for post-emergence control, but on farms with significant grassweed issues any opportunity should be taken for management within break crops.
“Grassweed control was the bigger concern this past year, and it is steadily becoming a more significant issue, exacerbated by the loss of carbetamide and reduced activity from propyzamide in dry, mild winters, plus the general drop in efficacy of graminicides.
“I have seen plenty of evidence of the efficacy of clomazone in sensitising grassweeds, and I think in a year like the one ahead it could have something to add to grassweed management as well as broadleaf weed control, assisting the efficacy of later applications of Centurion Max (clethodim) and Kerb (propyzamide) in a grassweed control programme.”
While growers are often cautious about early investment in OSR crops until there is evidence of good establishment and strong growth that can withstand pigeon and slug onslaughts, high commodity prices justify greater expenditure from the start this season, suggests Mr Gould.
“Beginning weed control with a pre-emergence application of a proven clomazone product such as Centium® 360 CS will provide a good basis not only for controlling broadleaf weeds, but potentially also provide a good foundation for grassweed control by sensitising emerging blackgrass.
“Oilseed rape was in the past perceived as a ‘cleaning’ crop that allowed weeds problematic in cereals to be tackled, but that reputation has suffered a little with poor weed control results in some recent seasons from certain strategies.
“There is a lot of blackgrass present in some winter cereals this year, perhaps due partly to earlier drilling after two wet autumns.”
Centium® 360 CS manufacturer FMC points out that a further benefit of early-stage broad-leaved weed management is that not only is weed competition reduced, but disease risk is also suppressed, with clomazone controlling Sclerotinia pathogen host weeds including chickweed, shepherd’s purse and hedge mustard.
Chickweed in OSR crop Image credit: Copyright Blackthorn Arable
“If they are allowed to contaminate the crop through to harvest, these can also affect crop glucosinolate levels, with the potential for penalties or rejection,” says Jeff Fieldsend, commercial agronomy manager at FMC.
“And while the sensitisation of grass weeds such as blackgrass, ryegrass and wild oats is not on the Centium® 360 CS label claim, the effect does also make follow-up grassweed treatments more effective.”
NOTES:
Centium® 360CS contains the active ingredient clomazone, offering broad spectrum weed control including a range of difficult weeds such as Cleavers, Chickweed and some Polygonum species. Other key species that are well controlled include Shepherds Purse, Fools Parsley and Hedge Mustard and Centium also has good activity on Groundsel, Knotgrass and Annual Sowthistle. Centium’s unique encapsulated CS formulation allows controlled release of the active ingredients, giving prolonged activity when needed most in the early growing season when weed pressure means that crops struggle to compete. In addition, FMC CS formulation technology reduces secondary drift and volatility in comparison to other formulations on the market – see website for technical information
That’s the advice from Agrii agronomist Simon Gould, who points out that the challenges – such as moisture conservation and seed-soil contact – involved in getting OSR established and away quickly to beat the threat of slugs and pigeons mean the importance of a strong weed control foundation is something growers can be tempted to put less emphasis on, according to whether they think the crop will make it strongly through its critical early stages.
“Even if the weather is warm and dry into the autumn, aiding crop growth, such conditions also mean later-applied residual grassweed herbicides may not work as well as expected,” he notes.
“Early broadleaf weed control in OSR is not so much of an issue, as there are effective options for post-emergence control, but on farms with significant grassweed issues any opportunity should be taken for management within break crops.
“Grassweed control was the bigger concern this past year, and it is steadily becoming a more significant issue, exacerbated by the loss of carbetamide and reduced activity from propyzamide in dry, mild winters, plus the general drop in efficacy of graminicides.
“I have seen plenty of evidence of the efficacy of clomazone in sensitising grassweeds, and I think in a year like the one ahead it could have something to add to grassweed management as well as broadleaf weed control, assisting the efficacy of later applications of Centurion Max (clethodim) and Kerb (propyzamide) in a grassweed control programme.”
While growers are often cautious about early investment in OSR crops until there is evidence of good establishment and strong growth that can withstand pigeon and slug onslaughts, high commodity prices justify greater expenditure from the start this season, suggests Mr Gould.
“Beginning weed control with a pre-emergence application of a proven clomazone product such as Centium® 360 CS will provide a good basis not only for controlling broadleaf weeds, but potentially also provide a good foundation for grassweed control by sensitising emerging blackgrass.
“Oilseed rape was in the past perceived as a ‘cleaning’ crop that allowed weeds problematic in cereals to be tackled, but that reputation has suffered a little with poor weed control results in some recent seasons from certain strategies.
“There is a lot of blackgrass present in some winter cereals this year, perhaps due partly to earlier drilling after two wet autumns.”
Centium® 360 CS manufacturer FMC points out that a further benefit of early-stage broad-leaved weed management is that not only is weed competition reduced, but disease risk is also suppressed, with clomazone controlling Sclerotinia pathogen host weeds including chickweed, shepherd’s purse and hedge mustard.
Chickweed in OSR crop Image credit: Copyright Blackthorn Arable
“If they are allowed to contaminate the crop through to harvest, these can also affect crop glucosinolate levels, with the potential for penalties or rejection,” says Jeff Fieldsend, commercial agronomy manager at FMC.
“And while the sensitisation of grass weeds such as blackgrass, ryegrass and wild oats is not on the Centium® 360 CS label claim, the effect does also make follow-up grassweed treatments more effective.”
NOTES:
Centium® 360CS contains the active ingredient clomazone, offering broad spectrum weed control including a range of difficult weeds such as Cleavers, Chickweed and some Polygonum species. Other key species that are well controlled include Shepherds Purse, Fools Parsley and Hedge Mustard and Centium also has good activity on Groundsel, Knotgrass and Annual Sowthistle. Centium’s unique encapsulated CS formulation allows controlled release of the active ingredients, giving prolonged activity when needed most in the early growing season when weed pressure means that crops struggle to compete. In addition, FMC CS formulation technology reduces secondary drift and volatility in comparison to other formulations on the market – see website for technical information
