Investment

Acute high temperature (HT, greater than 30°C) poses a significant constraint to lentil production in Australia, reducing yield, grain quality and production stability, particularly when occurring as acute heat waves during the reproductive phase. In southern Australia where lentils mature into terminal drought, decreasing plant available water and hot northerly winds compound the effects of acute HT stress, causing yield losses of up to 70%. The sensitivity of commercial cultivars to acute HT is evidenced by the performance of lentil lines within the 2008-19 National Variety Trials (NVT), where average grain yield was shown to decline by 2% per degree hour above 30°C for five commercial cultivars: Boomer, Nipper, Nugget, PBA Bolt and PBA Giant.

Using the NVT data for major lentil production regions within the Wimmera and southern Mallee, it was estimated that average annual yield losses due to acute HT are 1.5 t/ha (based on a yield potential of 3.1 t/ha). Using the long-term average lentil price of $600/t grain, this equates to an average annual on-farm loss of $900 per ha. Returns to growers are likely to be further diminished by seed quality downgrades caused by shrivelled and discoloured grain. It is believed that acute HT during the lentil reproductive period contributes to reduced grower profitability in most years.

This project will implement an innovative approach to deliver field-based phenotyping methods for evaluating, identifying and selecting lentil germplasm with acute HT tolerance; genomic tools to identify the best lines and parent combinations to accelerate breeding for improved acute HT tolerance; and prototype germplasm demonstrating the application of these phenotyping and genomic tools to increase genetic gain for acute HT tolerance in lentils. The project is expected to provide Australian lentil breeders with the knowledge and tools needed to develop cultivars with improved acute HT tolerance, which will lead to increased yield stability within Mediterranean-type regions and support the expansion of lentil into more marginal environments.