Growers look for consistency in oil seed rape
Agronomic characters such as disease resistance and plant height are being overlooked in favour of vigour and consistency in oilseed rape concludes a national survey.
Syngenta Seeds has been polling UK growers annually on variety selection, management and performance of their rape crops since 1999. The OSR Growers Survey is divided into two parts; before and after harvest. Results from Part 1 have reinforced the theory that varieties exhibiting strong establishment and consistent performance traits are influencing final variety choice.
Growers were asked to rank characteristics in order of importance when choosing a variety. Seed yield remains top priority when choosing an oilseed rape variety, with two out of three respondents picking the trait as either the first or second reason in variety choice. One in four placed standing power as the most important character ranking it second overall, followed by oil content.
Vigour, specifically seeking a hybrid or conventional, and variety consistency/past experience, came fourth, fifth and sixth respectively while traits such as plant height and disease resistance moved down the ranking. For growers in the Eastern region consistency and experience moved higher up the ranking, coming second after seed yield closely followed by vigour in third place.
Nigel Padbury, OSR sales, marketing and technical manager at Syngenta Seeds, says the survey results reflect the problems and frustrations associated with establishing and growing rape crops in the variable weather conditions experienced over the past few years.
"Vigour, consistency and experience were choices that we didn’t include on the questionnaire. Significant numbers of growers specified these traits under ’other’, placing them higher up the ranking than some of the traditional characters considered to influence variety choice," explains Mr Padbury.
"This year is the first time we’ve seen such strong evidence of a significant shift in how growers choose varieties. It’s a development that we’ve been aware of over the past few years through the survey and our breeders have already begun to respond through their selection process.
"The new high-yielding variety NK Grandia from Syngenta Seeds is one of the most vigorous conventional varieties commercially available. It establishes well with short, very stiff straw and a very high gross output that offers growers exceptional value for money and is available exclusively from Openfield this summer," he says.
Mr Padbury also believes growers are perhaps using vigorous, fast-establishing varieties as a rotational management tool to cope with resistant blackgrass populations in winter wheat. "Good rape establishment and growth is an important factor in blackgrass control for a following wheat crop. An uncompetitive rape crop just increases the grassweed problem."
The survey also highlighted a move away from hybrids this season back into conventional. In 2009 32% of the total surveyed area was planted with a hybrid variety compared to 25% this season. The area in hybrids is still higher than the 13.5% in 2008 but growers recognise that newer conventional varieties are achieving similar yields to hybrids in many situations.
"Growers are using hybrids as a management tool on more difficult soil-types, or for later sowing dates, because of better vigour and higher yields in situations where conventionals may respond differently," explains Mr Padbury.
More growers than ever before have completed the first phase of the annual two part survey. Over 23,000 ha of oilseed rape are represented in the survey, 4,500 ha more than last year. The Eastern and East Midlands regions have the highest crop areas represented in the survey at 22.4% and 21.8% respectively.
The final report, following completion of the Phase 2 questionnaire issued in August, will include details of final yields, standing power and diseases and is expected to be available in late September.
