In this series, Nicola Cannon, Principal Lecturer in Agronomy at the Royal Agricultural University, takes us through the mechanical weeding trial she's heading up.
You can see the trial results, plus the weeding kit in action, on 9 May. Tickets are free but limited, so make sure you reserve yours early
20 March 2017
The days are lengthening and warming and the wheat and weeds are really starting to grow. However, it seems that for every warm drying day, we have a wet blustery one, or at least part of the day meaning that soil conditions are still too wet to travel without making a mess. The weeds are becoming more erect in their growth habit and as a consequence will be causing more shading on the wheat crops.
These photos show the difference in wheat and weed ground cover between January and March.
The weeds will also now be competing strongly for nutrients available from the soil and necessitating control as soon as conditions allow to reduce competition for light and nutrients. Later on competition for water is also likely to be an important issue, especially on the thin Cotswold brash soils on which this experiment is being conducted.
The weeding equipment has started to arrive and the experimental design is finalised. The Garford Robocrop is here and the TRP Rotanet and the Combcut are ready for despatch. An initial assessment of weed and wheat biomass will take place as a baseline for the study.
The rest of the field has been ploughed in preparation for establishing the spring wheat which will be used for the weeding demonstrations during the event on 9th May – save the date! Hopefully, weather permitting, attendees of the event will be able to see the equipment running in this field where the crop will be less developed and also the impact of the weeders in the winter wheat where they will have already received one or two weedings.
The weeds have started growing despite the generally cold weather. However, the wheat seems to have developed very little. The weeds present are predominately broadleaved with speedwells, dead nettles, charlock and to a lesser extent poppy, chickweed, fumitory, cleavers, cranesbill, mayweed, docks. I’m sure there are many others as well! The wheat is around growth stage 21 or 22 (main stem and one or two tillers).
We have now agreed all the weeders for the winter wheat trial. They should arrive on the farm by this time next month, awaiting the appropriate weather window. The weeders will all run on the same day when weather conditions permit. However, the Garford Robocrob weeder would ideally be used straight away. This would allow the camera device guiding the weeder to help identify the rows of crops clearly before the weeds grow too much, making it even harder to distinguish the rows of wheat. This first weeding for the Garford could actually have been done when the ground was covered in frost, but unfortunately the weeders are not on site yet. It would also change the experimental conditions for this weeder.
George Hall from Garford assessing the crop to work out the best way to set up the machine.
20 January 2017
On this beautiful frosty day it is good to see that the second wheat on Roundabouts field at Harnhill Manor Farm is looking healthy (if rather crispy!) – a perfect site for a mechanical weeding trial.
The field is a clay loam with limestone fragments, so a fairly typical Cotswold brash soil.
The other side of Roundabouts field is in an overwinter stubble which will be drilled with spring wheat probably in March, this will be the site of the mechanical weeding demonstrations on 9th May (weather permitting) as the crop will be less mature.