OSR Establishment – After the heatwave: Part 1
7 Aug 2018
With many understandably concerned about the dry conditions when it comes to the establishment of oilseed rape, we asked Dr Pete Berry, Head of Crop Physiology at ADAS and our own oilseed rape expert, Clare Tucker for their advice on how to get your crop off to the best start.
Volunteer management following OSR harvest
But first a quick reminder on OSR volunteer management.
Dr Berry advises, “To minimise the chance of oilseed rape becoming a volunteer weed in following crops, cultivations should be delayed by four weeks in dry conditions, and two weeks when soils are moist.
This will allow the seed to germinate and the seedlings to be destroyed by subsequent cultivations.”
Establishment of 2018/19 OSR crop
With establishment often cited as the number one challenge when it comes to growing oilseed rape, Dr Berry shares his advice below.
“The most important requirement for good and rapid plant establishment is good seed to soil contact in moist soil”
In dry conditions, seed should be sown as soon as possible after cultivation to minimise moisture loss from the soil. Consolidation with rolling will then minimise moisture losses further, as well as reducing the risk of slug damage by restricting movement through the soil. If soils are very dry, then better to delay drilling until after some rain.”
If the top 50mm of soil is bone dry, then would need between 6mm (light soil) to 10mm (heavier soil) to bring it up to field capacity, so several mm rain should be sufficient.
“Don’t worry so much about the date, but more about the conditions and getting the seedbed right”
Clare Tucker echoes Dr Berry’s advice stating, “A good start is key for oilseed rape. This means good seedbeds and drilling when conditions are right for fast establishment. Don’t worry so much about the date, but more about the conditions and getting the seedbed right.”
Clare also highlights the importance of taking weeds out early to help with good establishment, since the crop is very sensitive to early competition. “If broadleaf weeds can be taken out early, they should be” Clare advises. “There are more spray days in September than in the months of October, November and December combined. Plus, if you spray late when soils are wet, you can cause more soil damage. Going early also avoids complications of having to work around a clethodim spray.”
In addition to enhanced weed control, dimethenamid-p containing herbicides* such as Springbok have the edge over solo metazachlor in dry conditions, as the active has multiple points of uptake into the weed.
“When it comes to black-grass control, Clare recommends a three-pronged attack of early residual, clethodim and propyzamide”
Finally, when it comes to black-grass control, Clare recommends a three-pronged attack of “early residual, clethodim and propyzamide to make sure you do as good a job as possible and the different modes of action help with resistance management.”