Summer spice technical report: Black sesame

Growing international consumer demand for sesame is delivering favourable market conditions, with the global crop valued at US$6.5 billion in 2018 and projected to reach US$17.77 billion by 2025. The Australian market is following this global trend, importing increasing amounts of both raw sesame seeds and value-added sesame products. In 2016 Australia imported 6740 tonnes of sesame and current trends indicate domestic demand will reach 9800t in 2025. The value of these sesame imports into Australia exceeded US$26.5 million in 2016 and demand since this time has been increasing. Previous attempts in Australia to establish sesame production in the early 1990s were focused on white sesame and did not gain momentum due to the low commodity price at the time and the inability for domestic producers to compete with imported products. The lack of support for commercial production was also due to a lack of supply chain options for suppliers and distributors. Black sesame is a high-value product returning approximately 45% more than white sesame (US $1229/t in 2018). Australia’s domestic demand is consistently increasing, and this, coupled with a significant global demand for black sesame, brings a new opportunity for Australian growers to enter into commercial production of black sesame. CQUniversity is supporting on-farm trials to evaluate the suitability of new black sesame germplasm for the sub-tropical and tropical environments of Northern Australia. This varietal material is provided by AgriVentis Pty Ltd. The CRCNA investment has enabled this work to move from laboratory trials to field trials across Northern Australia as part of multi-year project. This report provides the results of the first year of multi-location trials of four black sesame genotypes grown at six locations across Queensland and the Northern Territory. It covers the in-field crop agronomy and the results of the yield and quality analysis. The results from the first year of trials will inform the second phase of activities in the form of on-farm verification of black sesame technologies. The verification phase will be followed by commercial cropping, resulting in contract production in the third year of the project. Black sesame is a summer crop in Northern Australia, with a 90-120 day crop duration from planting until harvest. The crop has showed wide adaptability, demonstrating its potential to fit into cotton or sugarcane farming systems. The crop is known for its drought and heat tolerance making it a desirable crop choice for the environmental challenges experienced in northern Australia. The seed yield of the four varieties across each of the six trial locations, ranged from 1.37 to 3.04 t/ha, with the highest seed yield recorded in Biloela followed by Rockhampton, Katherine, Ayr, and Darwin, and the lowest yield recorded in Tully. This is significantly higher than the global average of 554kg/hectare. The seed yield between the varieties varied significantly at Biloela, Rockhampton and Darwin, but did not differ between the varieties at Ayr, Tully and Katherine, showing a significant genotype x environment interaction. Amongst the four genotypes tested, AVTBS#6 and AVTBS#11 recorded a higher yield compared to the other genotypes in Biloela and Rockhampton. In Darwin, the seed yield was greater for AVTBS#6, AVTBS#11 and AVTBS#16 compared to lowest yield AVTBS#3. However, it is important to bear in mind this is one year’s data only. The crop produced significant biomass in the range of 3-10 t/ha. This volume of biomass creates an opportunity for value-adding, with biomass waste being able to be used for briquettes and harvesting of antioxidants. The value of these bi-products and options for capturing this value during production, have not been examined as part of the trials to date. The highest standards for black sesame quality are set by the Japanese, with a requirement for 99.7% seed purity and above 46% oil. Other internations markets have lesser quality requirements than Japan (Pers.Comm. Lewis Hunter 2020). The quality attributes of the sesame seeds are reflected on the 1000 grain weight and oil content. The higher yielding genotypes such as AVT#6 and AVT#11 recorded greater 1000 seed weight compared to other varieties. The 1000 seed weight was low in Tully and Ayr, which is associated with greater rainfall during grain filling stages. Unlike the 1000 seed weight, the oil content across locations ranged from 37 to 47%, with no significant difference between the tested genotypes. The highest oil content from the seed was recorded from the Tully samples (47%), followed by Darwin (46%), a mid-range oil content was recorded in the samples from Katherine, Ayr and Rockhampton (44%), and the lowest in Biloela (43%). The next stage of research involves on-farm verification of selected genotypes from the first year for evaluation of the adaptability of the variety to local farming conditions. The early results are encouraging, however, there are still some challenges that need to be addressed for full fledged production including weed control, optimisation of mechanical harvesting, and providing robust agronomic information especially concerning optimum planting times on the different regions and density of planting. These activities are built into a parallel project funded by AgriFutures. It is pleasing to see the coordinated and collaborative approach to this work to support a new and emerging industry for northern Australia. The authors acknowledge the financial support of the Cooperative Research Centre for Developing Northern Australia and the support of its investment partners: the Western Australian, Northern Territory and Queensland Governments. We also acknowledge the financial and in-kind support of the project participants.