The mildest winter on record with spraying opportunities seriously limited by weather and ground conditions has resulted in an exceptional range and scale of late-winter weed growth to be controlled ahead of this seasons much greater area of spring cropping: a challenge not being helped by continued weather instability and uncertainty.
We’ve seen black-grass,in particular, continue to germinate and grow strongly throughout the winter,reported Procam head of crop production, Nick Myers. And spring germinators like chickweed and cleavers have been coming through and thriving in stubbles and cultivated ground alongside the inevitable charlock from well beforeChristmas.
Increased spring cropping on many farms gives an excellent opportunity for control this season. Equally, though, it puts far greater pressure on men and machines,and means extra in-crop expense and performance losses for those who don’t get things right from the start.
With storm systems bringing wind and rain on the one hand interspersed by brief periods of cold on the other, Mr Myers insists that patience and flexibility must be the twin watchwords this season; the patience to delay fieldwork until ground conditions are right and the flexibility to be able to make the most of every weather opportunity.
To rush in and drill into sub-standard seedbeds without sufficiently good pre-planting weed control would be a recipe for disaster, he stressed. With their short growing season and limited ability to compensate for setbacks, the secret of success with spring crops is to get them up and away as rapidly as possible and with minimal early weed competition.
So you need to be patient enough to wait for conditions that allow you to produce a good seedbed and flexible enough to be able to take full advantage of these conditions as soon as they arrive.
This and the acute weed pressures were seeing this season with big mats of black-grass in many cases means you’ve got to get your pre-planting control right first time. So you need to be spot-on with your glyphosate choice, rates and use.
Apart from a glyphosate you can rely on to work effectively under relatively cold early spring conditions you need a formulation with maximum rainfastness to take advantage of every spray window; and one which has the shortest cultivation interval for the least possible delay ahead of seedbed preparationor drilling.
Nick Myers explained that tillered annual grass weeds and easy-to-control broadleaves need
720 g/ha of Roundup for effective control and tougher annuals and perennials up to 1440 g/ha, pointing out that no amount of adjuvant will make up for a lack of active ingredient. Keeping rates up will be especially important for the greatest effectiveness and the least risk of resistance development wherever weeds are already moving into stem extension.
He advised applying in water volumes of 80-250 litres/ha through nozzles giving a medium-coarse spray, lower water volumes typically giving better results and nozzles inclined slightly towards the rear improving coverage.
The best spray coverage will be particularly important in cloddy conditions, NickMyers pointed out. Getting closer to the ground will help here, as will keeping sprayer speeds down. Lower drift risk formulations will be valuable too in ensuring the best possible targeting.
With a modern formulation like Roundup PowerMax you can also include glyphosate as part of your pre-em mix if you don’t have the time or the conditions aren’t right for the extra stale seedbed Im recommending this spring wherever feasible.
This will deal with any weeds emerging between cultivation and drilling or those transplanted rather than killed by working the soil. Compatibility with a wide range of pre-ems makes it particularly useful, although you must, ofcourse, ensure the application is ahead of any crop emergence.