Wheat quality: Stressed protein = inferior product

Farming packages to produce highprotein, high-quality wheat with less environmental stress - that's the aim of researchers from NSW, South Australia and Western Australia who are collaborating on field trials and analysis.

The project is coordinated by John Oliver, senior cereal chemist at NSW Agriculture's Agricultural Research Institute at Wagga Wagga and by Wal Anderson, W A Department of Agriculture. It is looking at farming practices and wheat genetics to find the best production package for highprotein, high-quality wheat. The aim is to reduce negative environmental effects, and still maintain farm profitability.

Mr Oliver said the project also recognises the need to improve the uniformity of wheat as a raw material and to extend the production regions of premium-attracting wheat.

He said that the work stemmed from trials by NSW Agriculture and CSIRO Plant Industry which showed that late fertiliser additions increased protein overall and helped achieve high protein levels in Prime Hard varieties in other than traditional growing areas.

All protein not the same

"In the past, when protein levels of 13 per cent and above have been achieved in southern Australia, it has usually been associated with low yields caused by stress such as drought, disease or late sowing. Under such conditions the protein quality is inferior to Prime Hard 13 grown in northern NSW and Queensland, even if the variety is the same," said Mr Oliver.

"These trials showed that if the high protein is achieved through adequate fertility in the absence of stresses, the quality elsewhere matches northern Prime Hard quality."

Similar interest was coming from University of Adelaide studies on the Eyre Peninsula and from the Geraldton region in WA. These areas are near the latitude of Condobolin in NSW where Prime Hard is successfully grown.

Collaborative links have led to a series of 12 trials from Moree in northern NSW to Minnipa on the Eyre Peninsula, coordinated by John Angus of CSIRO Plant Industry. Four varieties are undergoing nitrogen management regimes aimed at producing 13 per cent protein. Soil environment and weather at grain filling are also being monitored.

"The results should provide hard evidence about factors affecting protein quality and possible regional differences in protein quality," said Dr Angus.

NSW strategy

Mr Oliver said the best strategy in southern NSW seems to be late application of nitrogen fertiliser around flowering. "But it requires adequate moisture and that the nitrogen gets into the plant quickly," he said. "Application just before rain is an essential strategy for southern NSW or Victoria where the frequency of rain makes it a real proposition. Northern NSW, SA and WA require other strategies."

In SA and WA trials, researchers are using practices suited to the areas to ensure adequate nitrogen fertiliser is available to the plant during growth. They are also developing new varieties more suited to growing conditions in those target areas.

The three-year trials will compare varieties at the molecular level, to confirm that the quality is suitable. Performance will also be checked against dough behavioural analyses.

Harvesting smarter

Also of interest to growers should be two related wheat CRC projects. One is development of an on-farm antibody (ELISA) test allowing growers to assess the extent of rain damage to their crops. If growers could identify which areas are affected they could harvest accordingly. The benefit: sound grain would not be delivered and down-graded with weather damaged grain. Mr Oliver said that a prototype kit should be available for field evaluation by 1997.

Another potential paddock tool is a field sampling method for protein. Measuring protein development during grain filling would allow growers to predict final protein composition and make their marketing plans accordingly.

Subprogram 2.11.03 Contact: (NSW) Mr John Oliver 069 381 816; (SA) Mr Peter Ninncs 08 303 7802; (WA) Dr Wal Anderson 09 368 3521; (ACT) Dr John Angus 06 246 4911

Region North