Farming systems: groups join up, nail down trial design by Denys Slee

TOPCROP FARMING groups in the Victorian Wimmera have decided that coordinated trials will yield more information in a reliable fashion and be more efficient.

Instead of each group in the region doing its own thing, they are now coordinating their activities and investigating a single issue at a time using a standard trial design.

TOPCROP agronomist Brooke Thompson said that previously the groups faced results that were like comparing apples and oranges. In 2001 , for example, most of the groups participated in on-farm testing to examine issues such as crop nutrition, crop varieties, and pesticide selection and timing.

"While all of the sites were sown, maintained and harvested using conventional broadacre equipment, a range of experimental designs was employed. So it was not possible to combine the trial results to draw regional conclusions," she said.

In 2002, all that changed when trials of 10 wheat and 10 barley varieties were established by the groups. As well, in a partnership with the farming group Wimmera Farming Systems (WFS), four additional sites managed by WFS were set up.

Methods

Ms Thompson, whose work is supported by the GRDC, said that during a meeting early in 2002 at Nhill, representatives of TOPCROP groups selected cereals as the focus for that year and the individual varieties to be tested.

"Throughout the growing season, growers were encouraged to take ownership through regular group visits to the trials, monitoring of the trials by group members and making the sites available for individual visits," she said.

"This approach to variety evaluation allows farmers to take an active role in the selection and adoption of new crop varieties and the evaluation provides objective varietal information and locally relevant information.

"Each of the trial sites was sown with conventional broadacre equipment provided by the host farmer - plots being at least 9m wide and 100m long.

"Six wheat and four barley varieties, all commercially available, were tested at every site and, as well, the new wheat AnnuelloPBR logo and the new barley Sloop VicPBR logo were added to this list. Optional varieties were trialed in addition to the standard varieties to ensure each trial could include locally relevant varieties.

"All seed came from a central source to remove a potential source of error."

Trial design

Ms Thompson said the 'nearest neighbour' trial design was employed where every third plot was designated as a control - the control being the variety grown by the farmer in the remainder of the paddock. By using this design the possibility of paddock soil variability influencing results was minimised. She said that, by repeating the trials at a number of different sites, conclusions about variety performance across the region could be drawn, as well as providing localised information.

Plans for 2003

It had been hoped that trials in 2003 might involve new chickpea varieties but seed supplies had been limited by the drought. Instead it was likely that fertiliser rates following a drought would be the topic for wide-scale testing.

"The trial sites also provide exposure for companies and tbeir new varieties and allow growers to see how they compare agronomically," Ms Thompson said. "In the future there is potential for breeders to showcase new varieties in demonstrations with high levels of grower involvement and awareness, provided enough seed is available for large-scale comparisons."

Program 4 Contact: Ms Brooke Thompson 03 5362 2111