Minimum air temperatures less than 15°C had biggest impact on varietal performance. Cold damage during the months of June and July warrants selection of varieties with cold tolerance for this environment, especially for the aerobic rice system. Ponded water has 4-8°C advantage over the air temperature, thus providing some protection against such cold damage. This has resulted in higher yields under flooded system. Planting dates, varying from late-February to late-May, were found to play a crucial role for plants to escape the low temperature damage at critical growth stages. Among the varieties tested, selected tropical varieties yielded higher than the temperate varieties. Yunlu 29 has been identified as the best variety adapted for aerobic rice system in the Ord. NTR 426 was found to outperform all other tested varieties under the flooded system in this environment. Greater focus must be paid on quality of harvested grain. A complete analysis of data generated in trials conducted from 2009 to 2015 at all sites in WA and NT could help to identify environmental differences between sites and therefore target specific/broad adaptation of varieties with good yield stability. Future work in northern Australia should consider screening a greater range of fragrant and aromatic rice. Traditionally, fragrant rice varieties attain greater levels of aromatic components in tropical regions. These are high value varieties and represent opportunities for import substitution in Australian markets. There is an opportunity for Australia to tap further into the international rice market by producing these speciality rices in the tropical environments of northern Australia. These are some of the factors that need to be considered to establish a viable rice industry in the ORIA and NT regions. Rice crop modelling could add significant value and extend the experimental work and field trials, particularly in helping to quantify long-term risks in rice production due to low/high temperatures, climate change, and so on. Once they have been tested and validated, cropping systems models (for example, Agricultural Production Systems Simulator [APSIM]) can give valuable insights into climatic risks over a much longer period (50-100 years) than experiments/field-trials.https://researchlibrary.agric.wa.gov.au/books/1011/thumbnail.jp
