9 July 1999

Three-pass system for cereals savings

CEREAL growers looking for ways to reduce the costs of wheat production should consider combining lower cost establishment techniques with minimum pass crop husbandry, judging by the latest HGCA-funded research.

Work being conducted at three Arable Research Centres sites on second wheats is comparing three establishment systems (direct drill, minimum cultivation and ploughing) – followed by three different levels of crop management involving three, four and seven passes through the crop with nitrogen and agrochemicals.

"When you consider that most growers will make between seven and nine passes during the growing season, managing to get everything onto the crop in just three passes is quite a departure from normal practice," says ARC research co-ordinator Nick Poole.

Number of passes

"But for growers with a lot of land to cover, or with land some distance from their base, it can be attractive to reduce the number of passes made through the crop."

Added to the study has been the use of an experimental take-all seed treatment to assess its effect on take-all root infection. At all three sites, the plots were established into chopped wheat straw.

Best establishment was achieved with the plough and press system, confirms Mr Poole. "Establishment counts done at 1-2 leaf stage gave an average 74% establishment with the plough, compared to 66% with the minimal tillage system and 57% with direct drilling.

"The only exception to this was the heavy land site at Biggleswade, where minimal cultivations gave a slightly better establishment than ploughing. But whether these establishment counts will have any effect on final yields is unclear.

"At the end of May, it was very difficult to differentiate between the different establishment techniques, particularly at the Andover site, although the benefits of the take-all seed treatment MON65500 were visually apparent at all sites.

"And remember that there is a £30/ha difference in the costs of a plough system compared to direct drilling," he adds.

Monitoring of weed populations in the cultivation systems, carried out by IACR-Long Ashton, revealed no differences in the numbers of grass weeds that had emerged by November. However, at the Biggleswade site, the brome population is now considerably higher in the minimal cultivation plots than either the direct drilled or ploughed areas.

"Surprisingly there were a significantly greater number of broad-leaved weeds in the plough-based system at all sites, than there were in the minimum tillage systems."

Mr Poole adds that the lack of harvest results makes it impossible to make any firm conclusions from the work, so far. "But we know from previous trials that at low grain prices, minimum pass husbandry systems can be more profitable."

All treatments in the three-pass system were applied by flag leaf. "Weed control was done in the autumn with an IPU/DFF mix, which was applied with an insecticide," recalls Mr Poole. "The nitrogen was all applied in one go on April 1, and then a fungicide was used at flag leaf.

"Theres also the opportunity to add a cleavers herbicide at flag leaf, if required," he adds.

At a conservative farm cost of £5/pass, the three-pass system saves £20/ha just in application costs. "Then there are the extra input costs to consider. There are no PGRs applied in the three-pass system, for example."

Disease resistance

His advice to growers considering a reduction in the number of passes is to opt for a variety with both good disease resistance and standing power. "And choice of fungicide is also important. The strobilurins have helped, as they offer longer protection from a single dose."

He agrees that farms with resistant grass weeds or high weed populations will find it more difficult to use a minimum pass approach. "But otherwise its worth considering. If this latest research proves successful, it could be combined with low-cost establishment techniques. Together, they could save growers £50/ha." &#42