National Winter Oilseed Rape Establishment Poll

OSR Establishment Results

Summary

The latest Bayer Crop Science study undertaken in late October/early November involved over 290 growers across the country planting more than 30,000ha of winter OSR for 2023.

• At 106ha, the average planted area was almost 20% up on the previous season and almost back to the average 110ha of 2019, just under half the growers planting more OSR than last season and fewer than 20% less.

• A broad cross-section of almost 60 varieties of six main types are being grown, with the marked swing to hybrid varieties and decline in pure lines evident amongst mainstream ‘double low’ growers last season continuing.

• Direct drilling has become almost as popular as minimum tillage as the main establishment regime, with around four in every 10 growers employing it this autumn and only 3% continuing to rely on the plough.

• Driven by the very dry early autumn, there was a clear reversal in the trend to earlier drilling recorded in the past three years of Dekalb studies, over 40% of growers sowing the bulk of their crops before August 20compared to 55% in 2021.

• While all regions experienced more pressure from cabbage stem flea beetle than the past two seasons, the level of challenge from the pest was much lower than the last really bad CSFB season of 2019/20.

• The earliest sowings continued to see the least challenge from the pest, with particularly marked year-on-year increases in CSFB pressure reported for later sowings.

• Moisture conditions at sowing were noticeably worse than the last most problematic establishment season of 2019, all regions experiencing particularly dry seedebeds.

• Thankfully, most growers report receiving sufficient rainfall since sowing, with those in the northern regions getting markedly more than those in southern England.

• All growers are employing one or more of the six most popular establishment management techniques, minimising soil movement continuing to be the most widely used with seedbed fertilisation also being employed by half or more growers.

• Even though greater CSFB pressure has meant a higher proportion of growers spraying insecticide at establishment this season, this has not led to a decline in the proportion of those deliberately avoiding spraying to encourage predators. Most encouragingly, almost half of direct drillers (48%) are now deliberately avoiding insecticide spraying.

• At less than 5% of the crop area, the amount of redrilling necessary was much less than the 14% recorded in the very poor season of 2019/20 and similar that of 2020/21.

• Almost exactly 5% of the drilled/re-drilled hectares are likely to be the subject of claims under one of the 2022 season establishment schemes offered by seed suppliers. Accounting for further crops written off over the winter, this suggests overall crop survival to the spring is likely to be more similar to the 90% of the past two seasons than to the 67% of 2019/20.

• This encouraging prospect is reinforced by an average score of 7.3 on the 0-10 scale

(where 0 = complete failure and 10 = perfect establishment) with almost 80% of this season’s crop rated 7.0 or more for establishment and just 7% rated less than 5.0.

• While western and southern England fared worse than the northern regions in particular, all parts of the country reported crops in perfectly acceptable condition.

• Almost certainly reflecting the drier conditions for longer experienced by the earlier sowings, there was little difference in average establishment score between August sowing dates despite different levels of CSFB pressure.

• The major impact of CSFB continues to be underlined in an average establishment score difference between the least and significant pressure from the pest – across all sowing dates and moisture conditions at and after sowing – of fully 3.0 points.

• Moisture conditions at sowing had much less of an effect on establishment than CSFB pressure, with an average difference of less than 1.0 establishment point between very dry and reasonable conditions.

• Rainfall after sowing, however, had a much greater effect, the average establishment score difference between almost none or very little rain and a decent amount being virtually identical to that between little and significant CSFB pressure.

• Despite coming under greater CSFB pressure (by virtue of being sown rather later than pure line varieties) hybrids showed their value by establishing every bit as well.

• There is a suggestion that subsoiler seeding was more successful than direct drilling, in particular.Once the fact that fewer direct drillers used an insecticide at establishment is taken out of the equation, though, the difference is questionable.

• Spreading organic manures and seedbed fertilisation were the only management techniques giving noticeably higher establishment scores when employed in the absence of any other.

• Insecticide use at establishment is still having a positive effect on crop condition. With the exception of crops under the greatest CSFB pressure, however, growers deliberately avoiding insecticides do not appear to be losing out to any particular extent in their establishment, and may even gain through subsequently through greater pest predation.

The Poll & Sample

The on-line Bayer Crop Science study was undertaken in late October/early November to assess the relative success of winter oilseed rape establishment across the country in the face of this season’s pressures. Identical core questions to the previous three years of studies provide a good basis for benchmarking establishment experience.

Results were analysed from over 290 growers from England, Scotland and Wales planting more than 30,000ha of winter OSR for the 2023 harvest. While this was a noticeable increase in numbers involved from previous years, the distribution of growers across the main arable areas of the country (Figure 1) was almost identical_,_ allowing meaningful comparisons to be made with previous seasons.

Figure 1: Regional Distribution of Growers (2022)

Planting Changes

At 106ha, the average planted area was around 19% up on the previous season’s 89ha, itself higher than the 85ha average of 2020 and almost back to the average 110ha in 2019.

Confirming this increase, just under half the growers reported planting more OSR than last season (41% of these much more) while less than 20% reported decreased plantings (Figure 2).

Figure 2: Plantings (2022 vs 2021)

Noticeably more growers than the average in Eastern England, the East Midlands and Southern England planted more OSR this season, while those in the West Midlands & Wales planted rather less.

Variety Types

As in the previous years, a broad cross-section of almost 60 varieties of six main types are being grown (Figure 3).

Figure 3: Main Variety Types (2022)

The marked swing to hybrid varieties and decline in pure lines evident amongst mainstream ‘double low’ growers last season has clearly continued (Figure 4).

Figure 4: Main Variety Types (2019 - 2022)

Establishment Regime

Direct drilling has become almost as popular as minimum tillage as the main OSR establishment regime, with around four in every 10 growers employing it this season. Just under 20% are using some form of subsoiler seeding while only 3% are continuing to rely on the plough.

The popularity of direct drilling has clearly increased over the past four seasons, with both subsoiler seeding and plough-based establishment declining noticeably (Figure 5).

Figure 5: Main Establishment Regime Changes (2022 vs 2019)

Sowing Date

Some 42% of growers sowed their crops before August 20 this autumn, with only 7% doing so before the end of the first week in August. Fully 20% of crops were planted in September (Figure 6).

Figure 6: Sowing Date Distribution (2022)

A clear reversal of the trend towards earlier drilling in the past three seasons (Figure 7), this is almost certainly a consequence of the very much drier August.

Figure 7: Sowing Date Distribution (2019 - 2022)

Considerable variations continue to be apparent in sowing dates across the main regions of the country (Figure 8).

Figure 8: Regional Sowing Date Distribution (2022)

With the possible exception of the East Midlands, sowing in all regions was noticeably later than last season.

Overall, pure line varieties tended to be sown somewhat earlier than hybrids (Figure 9).

Figure 9: Sowing Date by Main Variety Type (2022)

* Excluding Clearfield, clubroot resistant, HOLL & HEAR varieties

Cabbage Stem Flea Beetle Pressure

The pressure from cabbage stem flea beetle was noticeably greater than the past two seasons, with 20% of growers reporting a substantial or intense challenge. A greater proportion (28%) however, saw little, if any, challenge.

In both respects, CSFB pressure was clearly less than 2019 when over 50% of growers experienced substantial or intense challenges from the pest and only 17% saw little or no challenge (Figure 10).

Figure 10: Overall CSFB Pressure at Establishment (2019 - 2022)

All regions experienced more pressure from CSFB than the previous season. As in the past, the degree of pest challenge varied across the country, with Yorkshire & Humberside seeing perhaps the greatest pressure this season (Figure 11).

Figure 11: Regional CSFB Pressure at Establishment (2022)

All sowing dates also saw greater pressures from CSFB than last season with the earliest sowings continuing to have the least challenge from the pest and later sowings the greatest (Figure 12).

Figure 12: CSFB Pressure at Establishment by Sowing Date (2022)

Particularly marked year-on-year increases in flea beetle challenge were evident in late August and September sowings. Again, though, these were nowhere near the pressures experienced in 2019.

Reflecting the fact that a greater proportion were sown in the later slots, hybrid varieties came under rather greater CSFB pressure than pure lines (Figure 13).

Figure 13: CSFB Pressure at Establishment by Main Variety Type (2022)

* Excluding Clearfield, clubroot resistant, HOLL & HEAR varieties

Moisture Conditions

Two thirds of growers reported very or fairly dry conditions at sowing, with only just over a third considering them at least reasonable. Moisture conditions at sowing were noticeably worse than the last most problematic establishment season of 2019 (Figure 14).

Figure 14: Moisture Conditions at Sowing (2022 vs 2019)

All parts of the country experienced particularly dry conditions at sowing, with Southern England, the West and East Midlands the driest (Figure 15).

Figure 15: Moisture Conditions at Sowing by Region (2022)

Crops drilled earlier in August experienced noticeably drier seedbed conditions than those planted later in the month and into September, in particular (Figure 16).

Figure 16: Moisture Conditions at Sowing by Sowing Date (2022)

* Relatively small sample size – treat with caution

Thankfully, most growers report receiving sufficient rainfall since sowing, with those in the northern regions, not unsurprisingly, getting markedly more than those in southern England (Figure 17).

Figure 17: Rainfall since Sowing by Region (2022)

While all crops received enough rainfall after sowing regardless of sowing date, the proportion receiving plenty of rain was noticeably less for September sowings (Figure 18).

Figure 18: Rainfall since Sowing by Sowing Date (2022)

* Relatively small sample size – treat with caution

Establishment Management Techniques

All growers are employing one or more of the six most popular establishment management techniques, using 2.5 of them of average.

Minimising soil movement continues to be the most widely used technique, with seedbed fertilisation also being employed by almost half or more growers (Figure 19).

The relative use of these remains little changed over the four years of studies to date, although the number of growers employing double rolling each season is naturally influenced by soil conditions.

Figure 19: Main Management Techniques (2022 vs 2021)

Insecticide Use

Unsurprisingly, the greater CSFB pressure meant a higher proportion of growers spraying insecticide at establishment this season – 54% compared to 45% in 2021.

Encouragingly, though, this has not led to a decline in the proportion of those deliberately avoiding spraying to encourage predators. If anything, indeed, this has increased slightly – from 33% in 2021 to 36% this season (Figure 20).

Figure 20: Insecticide Use at Establishment (2022 vs 2021)

Encouragingly too, almost half of direct drillers (48%) are now deliberately avoiding insecticide spraying at establishment, and only 44% actually used a spray this season.

This may reflect a more ‘conservation-focussed’ approach on the one hand and less need as a result of better conditions for crop establishment on the other.

Establishment Success

Of the 30,930ha drilled less than 5% (1543ha) had to be re-drilled. Similar that of 2020/21, this was noticeably less than the 14% recorded in the very poor season of 2019/20.

Almost exactly 5% of the drilled/re-drilled hectares (1591ha) are likely to be the subject of claims under one of the 2022 season establishment schemes offered by seed suppliers, indicating an overall establishment success rate of 95%.

While there will almost inevitably be further crops written off over the winter for one reason or another, this suggests overall crop survival to the spring is likely to be more akin to the 90% or so recorded in the past two seasons than the 67% of 2019.

This encouraging prospect is reinforced by an average score of 7.3 on the 0-10 establishment scale (where 0 = complete failure and 10 = perfect establishment).

While not as high as that recorded in either of the past two seasons, this is noticeably better than the 6.5 average of 2019. (Figure 21).

Figure 21: Overall Establishment Scores (2019 - 2022)

Encouragingly too, more than three quarters of growers rate their OSR establishment this season at 7.0 or more, with less than 10% rating it as less than 5.

In area terms, almost 80% of this season’s crop is rated 7.0 or more for establishment with just 7% rated at less than 5.0 (Figure 22).

Figure 22: Establishment Score Distribution (2022)

With the exception of Eastern England, all regions saw less good establishment than last autumn, though in all case it was very reasonable.

Northern regions continued to achieve the best results, while western and southern England fared worst and saw the biggest year-on-year decline in establishment success (Figure 23).

Figure 23: Establishment Score by Region (2022 vs 2021)

Other than for September sowings, there was little, if any, difference between average establishment scores for the different sowing dates despite different levels of CSFB pressure (Figure 24).

Figure 24: Establishment Score by Sowing Date (2022)

* Relatively small sample size – treat with caution

This almost certainly reflects differences in moisture conditions at and after sowing, with earlier August sowings generally experiencing drier conditions for longer than those later in the month.

As in the past, the degree of establishment success was clearly related to the level of CSFB pressure (Figure 25). Average establishment scores for each level of pest challenge were, indeed, almost identical to those of 2021.

Figure 25: Establishment Score by CSFB Pressure (2022)

The major impact of CSFB continues to be underlined in an average difference between the least and most pressure from the pest – across all sowing dates and moisture conditions at and after sowing – of fully 3.0 points on the 0-10 establishment scale.

Establishment success was equally clearly related to both moisture conditions at sowing and the amount of rainfall received subsequently.

Moisture conditions at sowing had much less of an effect on establishment than CSFB pressure, with an average difference of less than 1.0 establishment point between the driest and reasonable conditions – across all sowings dates, levels of CSFB pressure and rainfall post-sowing (Figure 26).

Figure 26: Establishment Score by Moisture Conditions at Sowing (2022)

In contrast, rainfall after sowing had a much greater effect, the average difference between almost none or very little rain and a decent amount – across all sowings dates, levels of CSFB pressure and moisture at sowing – being almost identical to that between most and little CSFB pressure (Figure 27).

Figure 27: Establishment Score by Rainfall after Sowing (2022)

Given the particular influence of the weather on all plantings, there was little difference between the establishment scores of hybrid and pure-line varieties. And this despite the fact that, by virtue if the time they were sown, hybrids came under greater CSFB pressure.

No establishment regime showed any marked difference from the average in establishment score either.

There is a suggestion that subsoiler seeding was more successful than direct drilling, in particular (Figure 28). Once the fact that fewer direct drillers employed an insecticide at establishment is taken into consideration, though, any real difference is questionable.

Figure 28: Establishment Score by Regime (2022) - Overall

Again, no management technique showed any marked establishment score difference from the average, although (regardless of other techniques used alongside it) those spreading organic manures reported the greatest success for the second year in a row (Figure 29).

Figure 29: Establishment Score by Management Technique (2022)

Spreading organic manures and seedbed fertilisation were, indeed, the only techniques giving noticeably higher establishment scores when employed in the absence of any other main technique (Figure 30).

Figure 30: Establishment Score by Individual Management Technique * (2022)

* Insufficient sub-sample sizes to draw any conclusions for any other techniques employed alone.

Interestingly too, no combination of techniques stood out as giving better establishment, either, suggesting that the most important thing (other than possibly starter nutrition) is matching establishment approach to specific soil and weather conditions.

Reflecting CSFB pressure, more than anything else, crop establishment has been noticeably better than average where no insecticide spray was needed and rather worse where more than one spray proved necessary (Figure 31).

Those deliberately avoiding spraying to encourage predators experienced slightly less good – but still very reasonable – establishment. What’s more, greater predation may mean they gain from lower levels of larval damage.

Figure 31: Establishment Score by Insecticide Use (2022)

Clearly, insecticide use at establishment is still having a positive effect on crop condition, especially so where CSFB pressure is higher.

With the exception of crops under the greatest pressure, however, growers deliberately avoiding insecticides at this stage are equally obviously not losing out to any particular extent in their establishment from doing so (Figure 32).

Figure 32: Establishment Score by CSFB Pressure and Insecticide Use (2022)