Recommended Listwinter oilseed rape trials in the east of England got off to a faltering startlast autumn. This reflects the situation growers experienced with commercialcrops. Exceptionally dry weather in Septembercaused problems in Suffolk, Essex and Kent trials, with dry soil conditionsleading to uneven and slow emergence and attack from cabbage stem flea beetle. In East Anglia, over half of the trials havebeen lost, two were lost due to cabbage stem flea beetle damage, and a third froma combination of cabbage stem flea beetle and poor establishment. A furthertrial in Kent was lost from uneven emergence and poor establishment. The 2015yield averages reported here do not include results from these abandoned trials.
Warm autumn cultivates good establishment
The Yield PlateauProject, funded by AHDB and Defra; written by NIAB, identified warmth andsunshine in October and April as positive characteristics which can lead togood oilseed rape yields.
Met officeinformation shows above average temperatures and average sunshine compared tothe 30-year averages in the east for October 2014. April 2015 saw temperaturesat or above average and sunshine above average when compared to the thirty-yearaverage. Trial results and Met Officedata to date are showing higher than 4-year averages, supporting findings inthe Yield Plateau Project.
Turbulent trendsslow late spring growth
A short heatincrease in early July did little to advance Oilseed Rape growth after a coolMay and June which has seen slower than usual maturity, especially in theNorth, with most trials yet to be harvested.
This weeksoilseed rape harvest results has information from four trials in Hampshire,Norfolk, Yorkshire and Oxfordshire. Yields are reported as gross output; seedyield adjusted for oil content. Values are represented as a percentage of thecontrol varieties Vision, PR46W21, DK Cabernet and PT211. Oilseed rape trialscan be more variable than cereals and care must be taken when drawingconclusions on limited data.
Four-year average increases
The 2015 grossoutput value of 5.6 t/ha is above the four year average of 5.27t/ha. TheOxfordshire trial has produced a high gross output yield of 6.16t/ha.
The 2015 grossoutput provides a snap shot as to how varieties performed in 2015. Thefour-year average values provide a better picture to variety performance overseveral years.
In 2015, at the foursites, higher yielding varieties include Arazzo (110%), Fencer (108), Campus(107), Incentive (107), V316OL (106), Avatar (106), Charger (106) and Harper(106).
Based on thefour-year average values, the highest yielding varieties to date are V316OL ahigh oleic, low linolenic (HOLL) variety at 108, Incentive (107), SY Harnas(106), Charger (106), Campus (106), Arazzo (106), Fencer (105), Popular (105)and Picto (105).
Resistant varieties improve
The clubrootresistant variety Mentor has a gross output of 102% which compares favourablywith the established clubroot resistant variety Cracker (94). The turnipyellows virus (TuYV) resistant variety Amalie currently has a gross output of102 in 2015 (100 in the four year average).
Candidate varieties showingsuccess
Gross output values for the candidate varieties show these newvarieties are performing well on the four-year average values. Precision andElgar have a four-year average gross output of 109%, and Nikita, Einstein,Wembley, Alizze and Windozz 108.