Date: 06/2020
Growing oilseed rape only on ground that will give it the best chance to thrive, optimising nutrition and managing drilling dates carefully, is critical to establishing the crop successfully, says Sentry Ltd’s business director John Barrett.
Responsible for farms throughout East Anglia and the South East, he believes Clearfield technology can also help significantly in terms of the crop’s early management.
“Two of our farms in this region were amongst the first in the country to grow oilseed rape and as one of our most profitable break crops, it remains a very important component in the rotation.
“High yields are only possible from healthy crops grown on soils that are in prime condition. We are very careful to grow the crop only on land where it has the greatest opportunity to perform well and on a wide rotation, no more than one year in five.
“One of our key priorities is to ensure that soils are healthy, contain the right amount and balance of nutrients, and are sufficiently resilient to cope with increasing extremes of weather.
“In 2018/2019, for example, the total annual rainfall was ‘average’ for this area, around 620mm, but that figure masked the fact that during the growing season the crop had to contend with periods of extremely dry and extremely wet weather.
“As an industry, we have been very reliant on crop protection products for many decades but looking ahead that is likely to change, making crop and variety selection even more important.”
This season, as for the last six years, 50% of his cropping is down to Clearfield varieties with the most recent introduction being DSV’s Phoenix CL.
“In assessing which oilseed rape varieties to grow I look for a combination of excellent yield potential, strong autumn vigour and good disease resistance, which will become increasingly important against a backdrop of declining access to agrochemicals.
“Where historically we have had issues with charlock, or after wheat crops where a sulfonylurea herbicide (SU) has been used, for example, we tend to grow Clearfield varieties for the additional confidence which they provide.
“Another important benefit is that they avoid the need to use a pre-emergence herbicide which can adversely affect crop development, which we have experienced, whilst reducing front-end costs and therefore the financial downside in the event of crop loss.”
Establishing Clearfield varieties
In the post neo-nicotinoid era with good crop establishment being harder to achieve, many growers have seen significant benefits from choosing Clearfield varieties, says DSV’s Sarah Hawthorne.
The approach gives them more options in terms of drilling and agronomic strategies, she explains.
“Clearfield oilseed rape solves a number of key problems for growers, namely the limited timing flexibility of herbicide options and reliance on pre- and early post-emergence residuals.
“The wide germination window for broad-leaved weeds, increasing problems with cruciferous weeds and the impact of problem weeds and volunteer OSR on sample quality, can also be addressed by Clearfield.
“It also reduces the intensity of workload around oilseed rape planting time, dependence on seedbed conditions and the need for rapid establishment. Companion cropping with Clearfield varieties is also gaining interest.”
Phoenix CL is DSV UK’s biggest selling Clearfield variety and after being commercially available in Europe for a couple of years was introduced to the UK following extensive trialling, she points out.
“It has been proven to have outstanding autumn vigour, produces robust plants with deep tap roots and a seed yield of 103%, while at 44.7% its oil content is one of the highest of any Clearfield variety.
“It also offers benchmark disease performance, scoring 6 for Light Leaf Spot and 6 for stem canker, with enhanced pod shattering resistance giving extra flexibility at harvest.”
Achieving optimum early growth
How well oilseed rape establishes has by far the greatest influence on how it yields, so Sentry’s focus is very much on getting the crop off to the best possible start, John Barrett says.
“Timing the sowing of oilseed rape has become much more critical in the last few years.
“With the loss of neonicotinoid seed treatments drilling later has become a higher risk strategy because of the potential impact of drought and cabbage stem flea beetle.
“Until now we have not suffered too badly from the pest, but it has been a significant factor in our decision to bring forward the drilling date.
“Until two years ago we started drilling oilseed rape on 15 August and finished at the end of that month, but now we begin on 5 August and aim to be done by 20 August.”