Sesame knowledge building in northern Australia

Held at the Kiely family's Deneliza Downs property, the field day, which focuses on new crop options to maximise returns in broadacre rotations, was hosted by the Northern Australia Crop Research Centre of Excellence.

During the summer of 2022/23, two varieties were evaluated at Deneliza Downs. The first was Equinom's ES103 (Highway), a white variety, and black sesame, Sesaco's S57B.

Plant density at establishment and harvest was recorded, along with days to flowering, yield potential through hand harvesting, and commercial machine harvest yield.

Overall yields for the summer season were quite low, only achieving a yield potential of 483.2 kg/ha for ES103 and 323 kg/ha for S57B, and a harvested yield of 114.8 and 39.6 kg/ha respectively.

Although the yield potential and actual harvested yields were very low, the yields for ES103 were significantly higher than for S57B.

The first factor that was likely to have influenced the low yields was low temperature stress because of the late planting date.

Daytime temperatures between 25 and 27 degrees are ideal, but during this crop the average daily temperature was below 20°C from late April onwards, which has likely led to slower crop maturity.

Temperatures below 15 degrees during flowering results in pollen sterilisation and low seed formation, and below 10 degrees crop growth and germination stop.

Other possible causes were weed competition early in the crop, and sesame leaf webber.

The Cooperative Research Centre for Developing Northern Australia has been working on the spice project for the past five years, working with farmers, researchers, advisers, commercial seed companies.

According to Central Queensland University researcher Dr Tieneke Trotter, in the current market farmers could be getting anywhere between $1,000 and $1500 a tonne for sesame.

"It could potentially fit in as a short season crop around the major crops, such as cotton, which often is irrigated and needs that water allocation," Dr Trotter said.

"If we have enough moisture in the soil to be able to get the sesame up and growing it can then cope with a little bit of a dry period.

"With every crop, and sesame is no different, to have good moisture around the time that your grain filling or that you're producing that product is really important for yield.

"But that's not to say that if there is a dry period that it's not going to still produce a reasonable crop that could be sold."

Hand-harvested seeds yields of up to 3t/ha were recorded during the Spicing Up the North project, however, seed loss from the shattering varieties was considerable when machine harvested.

AgriVentis Technologies' Andrew McDonald said the new, non-shattering varieties of black and white sesame were now available through AgriVentis Technologies.

"These are being evaluated as part of the Sesame Central programs of research, along with new methods of mechanical harvesting to maximise yield capture and return to farmers," Mr McDonald said.