Lentil (Lens culinaris Medik.) production in arable, Mediterranean-type climates is limited by heat waves and unreliable rainfall. Under climate change scenarios, increased atmospheric carbon dioxide (CO2) concentration will increase plant growth; however, the net effect of increasing occurrence and intensity of heat waves and drought is unclear. This study tested the response of combined acute high temperature (>32°C) at the early pod-filling stage and (i) crop-available soil water, and (ii) elevated CO2 on three lentil genotypes in two experiments. The three lentil genotypes selected were commercial cultivar PBA Bolt and two landraces sourced from the Australian Grains Genebank, AGG 71457 and AGG 73838. High soil-water availability (0.42 Mg m–3) throughout the growing season increased yield by 28% compared with low soil-water availability (0.35 Mg m–3). Across contrasting water treatments, there was no difference in patterns of crop response to high temperature during the early pod-filling phase (5 days at 42°C daytime, 25°C night), where yields were reduced by 45%. A significant interaction between high temperature response and genotype was observed, where reduction in grain number was higher for AGG 73838 (0.20% per degree-hour >32°C) than for AGG 71457 (0.07% per degree-hour >32°C) or PBA Bolt (0.10% per degree-hour >32°C). For heat and CO2 effects, there was no significant interaction between high temperature (3 days at 38°C daytime, ambient night temperature) and CO2 treatment on yield components. There was, however, an overall trend of increased biomass, grain number and yield due to elevated CO2. Although non-limiting soil water did not reduce the impact of high temperature in this study, the range in response across genotypes to high temperature supports opportunity for increased adaptation of lentil toward increasing yield stability under effects of climate change.

Frost damage to broadacre crops can cause up to an 85% loss in productivity. Although growers have few options for crop protection from frost, a rapid method for assessing frost-induced sterility would allow for timely management decisions (e.g., cutting for hay and altering marketing strategies). Spectral mixture analysis (SMA) has shown success in mapping landscape components and was used with hyperspectral data collected on the canopy, heads, and leaves of wheat at different sites to determine if this could quantify frost damage. Spectral libraries were assembled from canopy components collected from local field sites to generate spectral libraries for SMA from which a series of fraction sets was derived. The frost (Fr) fraction was then used to estimate final yield as a means of measuring frost damage. The best-fitting Fr fractions to yield were derived from the same data set as the source Fr spectra, and these ranged over R² = 0.58–0.75 at the canopy scale. It was clear that spectral signatures need to be collected at scale to assess frost damage. While Fr fractions were able to estimate yield there was no “universal” endmember set from which a Fr fraction could be derived. The normalized difference vegetation index (NDVI) was not able to estimate frost damage consistently. Future work requires determining whether there is a “universal” set of endmembers and a minimum set of targeted wavebands that could lead to multispectral instruments for frost assessment for use in ground and aerial sensors.

Grains intended for human consumption or feedstock are typically high-value commodities that are marketed based on either their visual characteristics or compositional properties. The combination of visual traits, chemical composition and contaminants is generally referred to as grain quality. Currently, the market value of grain is quantified at the point of receival, using trading standards defined in terms of visual criteria of the bulk grain and chemical constituency. The risk for the grower is that grain prices can fluctuate throughout the year depending on world production, quality variation and market needs. The assessment of grain quality and market value on-farm, rather than post-farm gate, may identify high- and low-quality grain and inform a fair price for growers. The economic benefits include delivering grain that meets specifications maximizing the aggregate price, increasing traceability across the supply chain from grower to consumer and identifying greater suitability of differentiated products for high-value niche markets, such as high protein product ideal for plant-based proteins. This review focuses on developments that quantify grain quality with a range of spectral sensors in an on-farm setting. If the application of sensor technologies were expanded and adopted on-farm, growers could identify the impact and manage the harvesting operation to meet a range of quality targets and provide an economic advantage to the farming enterprise.

Lentil production in arable, Mediterranean-type climates is limited by acute high temperature (HT) commonly occurring during the reproductive stage. With changing climate and greater weather extremes, there is a need to increase the HT tolerance of lentil to sustain production, and global germplasm provides adaptation opportunities. The current study assessed 81 genotypes for HT tolerance from a range of global climatic zones. Field screening of germplasm was undertaken over two consecutive years (2014 and 2015), in southern Australia, using a late-sowing approach, which included a subset of 22 genotypes that were screened in both years. Partially shaded temperature treatments within a split-plot arrangement were used to generate two different HT profiles. Stress indices, i.e., the yield stability index (YSI), the stress tolerance index (STI), and a third proposed high-temperature tolerance index (HTTI), were applied to rank the HT tolerance of germplasm. In 2014, under field conditions associated with natural temperature ranges that were favorable for screening, the following five landraces with increased temperature tolerance were identified: AGG 73838, AGG 70118, AGG 70951, AGG 70156, and AGG 70549. Among the 10 commercial varieties tested, one variety (i.e., cv. Nipper) was observed to have HT tolerance. For the YSI, which had the greatest amount of consistency in response across the 2 years (11 of the 22 genotypes), there were two genotypes (AGG 71457 and Nipper) which maintained their yield stability. These results demonstrate the opportunity that germplasm provides to improve the adaptation of lentil to HT. Ultimately, the late-sowing approach is one possible methodology to integrate into contemporary breeding programs for improving adaptation of lentil within Mediterranean-type environments.

Mungbean is grown as a summer crop in subtropical climates globally. The global demand for mungbean is increasing, and opportunities exist to expand production regions to more marginal environments, such as southern Australia, as an opportunistic summer crop to help meet the growing global demand. Mungbean has the potential to be an opportunistic summer crop when an appropriate sowing window coincides with sufficient soil water. This expansion from subtropical to temperate climates will pose challenges, including low temperatures, a longer day length and a low and variable water supply. To assess mungbean suitability to temperate, southern Australian summer rainfall patterns and soil water availability, we conducted field experiments applying a range of water treatments across four locations with contrasting rainfall patterns within the state of Victoria (in southern Australia) in 2020–2021 and 2021–2022. The water treatments were applied prior to sowing (60 mm), the vegetative stage (40 mm) and the reproductive stage (40 mm) in a factorial combination at each location. Two commercial cultivars, Celera II-AU and Jade-AU, were used. Water scarcity during flowering and the pod-filling stages were important factors constraining yield. Analysis of yield components showed that increasing water availability at critical growth stages, viz. the vegetative and reproductive stages, of mungbean was associated with increases in total biomass, HI and grain number in addition to increased water use and water use efficiency (WUE). Average WUEs ranged from 1.3 to 7.6 kg·ha⁻¹·mm⁻¹. The maximum potential WUE values were 6.4 and 5.1 kg·ha⁻¹·mm⁻¹ for Celera II-AU and Jade-AU across the sites, with the estimated soil evaporation values (x-intercept) of 83 and 74 mm, respectively. Nitrogen fixation was variable, with %Ndfa values ranging from 9.6 to 76.8%, and was significantly affected by soil water availability. This study emphasises the importance of water availability during the reproductive phase for mungbean yield. The high rainfall zones within Victoria have the potential to grow mungbean as an opportunistic summer crop.

In semi‐arid cropping regions where rainfall is variable, stored soil water is important for reducing the impacts of dry periods; however, in‐season evaporation limits yield potential. We tested the productivity benefits of protecting wheat and lentil crops from evaporation using inter‐row polymer cover, when grown in southern Australia. For wheat, white polyvinyl chloride (PVCw) increased yield by 50% (561 kg/ha) and 11% (408 kg/ha) for decile 2 (2018) and 3 (2019) seasonal rainfall respectively; and for lentil, yield increases were 20% (443 kg/ha) in 2019. A sprayable alginate polymer increased wheat yield by 8% (310 kg/ha). Total water use for wheat in 2018 was reduced (17 mm) for PVCw and water use efficiency (WUE) significantly increased from 7 to 11 kg/ha/mm, whereas in 2019, WU was greater (47 mm) for PVCw, but WUE was equivalent to the control (~15 kg/ha/mm). Colour of the PVC modified the light available to the crop and canopy temperature, where a highly reflective inter‐row cover (albedo 0.44) increased wheat yield (~487 kg/ha). For the future, formulations of highly reflective polymers applied in‐season within dryland cropping enterprises are likely to provide production advantages, although logistical viability of application and potential environmental implications may define impediments to adoption.