3 August 2001

Farms want reliable OSR

WINTER oilseed rape growers priorities when choosing varieties are shifting, according to a Monsanto PBIC Seeds survey.

Output, the combination of yield and oil content, remains the number one requirement. But reliability and disease resistance are key needs identified in responses from over 100 producers.

"Growers dont just want yield, they want varieties that are consistent both in yield and other factors such as establishment and crop growth," says the firms technical specialist Clive Sutton.

The telephone survey of 103 leading growers, each with an average of 50ha (125 acres) of rape, was carried out in May by the independent National Farm Research Unit.

Over half the growers (52.4%) made yield reliability their number one choice, 15.3% put disease resistance first and 13.2% saw standing ability as their prime requirement.

After last autumns spraying difficulties, which left many crops with more stem canker than growers like to see, disease resistance has leap-frogged standing ability, he says.

Resistance to lodging at flowering is well to the fore in the survey responses. "Semi-stiff varieties that produce leaning canopies at harvest can be an advantage, but lodging at flowering is a definite no no."

With harvest costing about 25% of the crops value, according to Claas, factors that increase its efficiency, such as short straw and low biomass, are of increasing value especially where growers have large areas to cut, he adds.

"Canberra is the shortest variety on the Recommended List. Being able to direct cut saves £30-35/ha on swathing. This can be about 7% of crop value, which is quite startling." &#42

Yield is too important to ignore

Reliablility is not generally at the forefront of growers questions when visiting trial plots, says NIAB oilseeds specialist Simon Kightley. "Nobody talks to me about reliability. Everyone hopes for it, but it is very difficult to measure because you need to assess it over many years. Individual performance can vary greatly between different seasons.

"The one question the survey clearly failed to ask is what is the value of high yield? Modern hybrids like Royal and Disco offer considerably more output than the best conventional varieties," says Mr Kightley.

Even weaker-stemmed conventional types like Escort and Madrigal offer very good yields now more growers follow breeders guidelines on reduced seed rates and growth regulator use, he says.