by Peter Reading
The Crop Doctor
Grains Research and Development Corporation (GRDC)

Loretta Serafin and Stephanie Belfield received a standing ovation at the end of the recent "Sunflowers ­ Bringing Gold back to the Northern Grains Industry" conference in Gunnedah, and rightly so.

Respectively New South Wales Department of Primary Industries (NSWDPI) district agronomists at Tamworth and Moree East, Loretta and Stephanie did many of "the hard yards" in organising the conference, obtaining financial support from a range of sponsors that included the Grains Research and Development Corporation (GRDC) and the Australian Oilseeds Federation (AOF).

But with that standing ovation the industry was also recognising the zeal ­ and success ­ with which the two agronomists have been promoting sunflowers as a viable and valuable rotation crop on northern region grain farms.

NSWDPI estimated sunflower plantings in northern NSW were about 80,000 hectares in the 2005-06 summer cropping season, compared to about 30,000 hectares the year before.

Those 80,000 hectares were expected to yield 90,000 to 100,000 tonnes this year, when extreme heat stress during grainfill reduced yield potential. In the mid-1980s, the national crop reached 300,000 tonnes.

Market limitations and price concerns were the main reasons northern region graingrowers moved to other rotational crops over the last 10 to 15 years and the reasons for renewed interest in sunflowers include better prices for high-oleic and mono-unsaturated lines, the opportunity to sow early on the spring plant; improved varieties and enhanced agronomic knowledge of the crop.

While Loretta and Stephanie could point to better gross margin prospects than sorghum in their campaign to persuade more growers to plant sunflowers, they also organised on-farm, variety and agronomy trials around Moree and Gunnedah, to demonstrate first hand the advantages of growing sunflowers and the effects on the crop of plant populations and nitrogen rates.

The aim of the three-year, AOF funded project was to identify thresholds that would minimise the risk to growers of including sunflowers in their rotations and improve productivity.

They monitored 30 paddocks in 2003-04, 50 in 2004-05 and 60 in 2005-06, looking for benchmarks and interactions in a range of areas that included sowing dates, planting depth and populations, row spacing, variety selection, rotations, plant available water, in-crop rainfall, yield and oil
content.

One interesting aspect of their study was the variation in crop and yield response to fertiliser nitrogen. Increasing nitrogen appears to decrease oil content in the sunflower seed, for instance.

On the strength of their work, Loretta and Stephanie suggest nitrogen budgeting is essential to ensure available nitrogen and soil moisture are in balance, particularly in less than optimal yield situations.

The project is due to conclude in September this year, culminating in a 4 page brochure outlining the best bet management practices for growing sunflowers in the northern grains region,

The Crop Doctor, Peter Reading, is managing director of the Grains Research and Development Corporation (GRDC), Canberra.