The Crop Doctor - Grains Research and Development Corporation (GRDC)

The plant breeders call it “residual heterozygosity”. That any line of crop seed –  including those released as named varieties – will still retain some genetic variation, and that the variation can become increasingly evident with each successive replanted generation of the variety.

The impact of residual heterozygosity was very evident last year, with plant pathologists reporting major variation in resistance or susceptibility to stem rust in some wheat varieties.

Now Queensland’s Department of Primary Industries and Fisheries (QDPI&F) pulse specialists are looking at the impact that the quality of mungbean planting seed can have on crop growth, yield and – most importantly – the quality of the harvested grain.

The department’s specialist pulse agronomist, Mike Lucy, says there are few other broadacre crops where quality impacts so much on grower returns, and overall profitability as in mungbeans.

“Growers can lift the price they receive from $350 a tonne to as high as $700, solely on the basis of the quality of the harvest grain. Yet, despite the potential impact this can have on profitability, grain quality remains a sorely neglected area of crop management at both the research and commercial level,” Mr Lucy says.

“The QDPI&F pulse team is working closely with the Grains Research and Development Corporation (GRDC) supported project “Agronomic solutions for Queensland pulse growers” to address the quality issue in mungbeans.

“A range of different seed lines of the variety Emerald, including some lines of grower seed which have been retained on farm for up to 10 years have been planted in grain quality trials at Biloela, Emerald (CQ) and Warwick.

“These will be evaluated against the elite line of Reselected Emerald, which has only recently been bulked up from the original line of breeder’s seed used for the original release of Emerald in 1989.”

Mr Lucy says the three trials will be used to quantify the economic benefits of using elite seed and minimising the potential impact of “residual heterozygosity” on deteriorating grain quality.