Smart system provides flexible weed control
As featured in Arable Farming Magazine
Smart system provides flexible weed control
by Arable Farming Magazine May issue
The Conviso Smart sugar beet system offers benefits above just weed control for one Nottinghamshire grower.
The opportunity to rid his farm of weed beet served as the attraction, but the excellent weed control and the flexibility of just a single herbicide application have since persuaded Alistair Bowring that the Conviso Smart system has more to offer.
He says: I came at this purely for the opportunity it provided to grow beet in a high-pressure weed beet situation but hadnt appreciated how good the all-round weed control would be.
The Conviso One herbicide is excellent; weve never had cleaner beet.
It has a strong residual component, but it needs good soil moisture to be effective.
The contact is exceptional; nothing gets past it.
I have seen fat hen controlled past the advised timing of four true leaves and it is highly effective against all the weeds on the label, including volunteer potatoes, field bindweed, grass-weeds and, of course, non-ALS tolerant beet.
Targeted It is less effective against any un-emerged potatoes, but where they are through at the time of spraying, they are controlled.
This has largely removed the need for targeted herbicides such as Dow Shield.
Despite the strong performance, Mr Bowring has previously favoured a pre-emergence spray of Goltix 70SC (metamitron) + Efeckt (ethofumesate), but this is more to buy time in controlling broad-leaved weeds and annual meadowgrass before the weed beet came through.
Weed beet is my priority but were it not an issue I may do things differently.
Based on my experience of the past two years, I dont plan to apply a pre-emergence.
He concedes that were it not for weed beet, it is unlikely he would be growing the ALS-tolerant varieties that make up one half of the Conviso Smart system but has since come to value the wider benefits.
I can spray the crop when I want to.
I dont need to push it.
If I want to wait for a better day I can and I put weed control first while knowing the crop safety of the system will be good.
This season will be a good test.
On tenanted land next door, he has a further 42 hectares of standard beet which will provide a fair comparison to assess the two systems.
Theres no weed beet problem, but a high weed burden means I am expecting to apply a pre-emergence spray of Goltix 70SC and at least three post-em sprays, probably including Debut and Dow Shield, and possibly a fourth spray of some kind.
If I cant achieve a comparable level of weed control with classic herbicides, then it will likely go over to Conviso Smart too from next season.
After three years, the rotation has been adapted to reflect the restrictions on following crops.
He says: We always follow Conviso Smart sugar beet with two years of cereals, either winter wheat or spring barley, depending on the lifting date.
This overcomes the herbicide restrictions in potatoes and forage maize and means we can use Cruiser SB without breaching restrictions on flowering crops.
Rotation For this reason, beans are only grown on the heavy land and away from the sugar beet, while a one in 10-year rotation for carrots and one in five for potatoes helps to avoid crop damage or over-reliance on certain modes of action in following crops.
Bolters too are taken seriously and rogued as needed.
I am wary of exchanging one form of weed beet for another.
In 2020 we had no more than 20 bolters in one 10ha field.
In 2021 we experienced a few more, but these were rogued and destroyed.
Where weed beet appears in the following cereal, it is controlled with Spitfire.
While there are occasions when the weeds may be past the advised growth stage for Conviso One, Mr Bowring is careful to promote efficacy by applying in good conditions.
Im also wary there is a risk that I may be promoting herbicide insensitivity among my weed population, so while I might wait until there is a good flush of weeds through before I spray, Im careful to make sure I apply in good conditions.
The flexibility the Conviso One herbicide delivers around application timing is not to be overlooked.
An advantage of a single application is it can be timed for maximum benefit according to your situation.
The single application of one litre/ha is sensible from a resistance management perspective.
For the past two seasons, the Conviso Smart crops first Smart Janninka KWS and then Smart Rivetta KWS have produced adjusted average yields of more than 80t/ha.
Others may produce higher yielding crops, but its not a simple comparison, believes Mr Bowring.
In 2020, a season many may care not to remember due to drought and virus, our 44ha of Conviso Smart beet averaged 81.51 tonnes/ha.
This is above our five-year average and was more than enough to meet our contract tonnage of 3,400t.
Adjusted yields in 2021 were broadly similar but with higher sugar contents of 17.9-18.3%.
I appreciate that some standard varieties may yield higher, by my weed beet situation means I would not achieve anywhere near that.
Factor in the savings on other herbicides, for instance Dow Shield and Debut, or other post-emergence sprays and the costs of the Conviso Smart system dont look so high.
The rising cost of all crop protection products and of applying them is another factor Mr Bowring believes supports the Conviso Smart proposition.
I dont have a lot of road work to consider, but only having to make one herbicide application rather than four or five has obvious benefits.
I also have a beef enterprise which, along with the potatoes, often takes more time than I can spare.
It is at these times I truly appreciate the flexibility the Conviso One herbicide offers.