Winter wheat cultivars are defined as those that have an obligate vernalisation requirement that must be met before they will progress from the vegetative to reproductive phase of development i.e. they must experience a true winter before they will flower. Historically, very little breeding effort has been applied to the selection of winter cultivars suited to southern Australia, with the notable exception of the New South Wales Agriculture breeding program based in Wagga and Temora that ran from the 1960s until 2002.

A shift by growers to earlier sowing, increased usage of dual-purpose cereals, and research highlighting the whole-farm benefits of winter cultivars to average farm wheat yield has increased grower interest and demand for winter cultivars. Three major wheat breeding companies operating in southern Australia have responded by commencing selection for milling quality winter cultivars, the first of which was released in 2017.

Existing research relating to winter wheats in southern Australian farming systems is reviewed here, including interactions with agronomic management, environment and weeds and disease. It is concluded that winter wheats can offer significant production and farming system benefits to growers by allowing earlier establishment, which increases water-limited potential yield (PY_w) by ∼15% relative to later sown spring wheats, and makes forage available for dual-purpose grazing during vegetative development. Winter wheats sown early require agronomic management different to that of later sown spring wheats, including greater attention to control of grass weeds and certain diseases.

There are significant research gaps that will prevent growers from maximising the opportunities from new winter cultivars once they are released. The first of these is a well-defined establishment window for winter cultivars, particularly in medium-low rainfall environments of South Australia, Victoria and Western Australia that have not historically grown them. There is circumstantial evidence that the yield advantage of early established winter wheats over later sown spring wheats is greatest when stored soil water is present at establishment, or the soil profile fills during the growing season. Explicit confirmation of this would allow growers to identify situations where the yield advantage of winter wheats will be maximised.

Given the imminent release of several new winter wheat cultivars and the increases in PY_w that they embody, it is critical to experimentally define the management and environmental conditions under which performance of these new genotypes are optimised, before their release and availability to growers. Optimising the genotype × environmental × management interactions possible with these cultivars will empower growers to make the best use of the technology and better realise the gains in water limited potential yield possible with these genotypes.

Frost damage causes significant production losses and costs to Australian dryland wheat, and frost impacts are not expected to decline in the near future, despite global warming. Rapid estimation of frost damage to crops on a spatial basis would allow for timely management decisions to reduce the economic impact of frost events. In this paper, we take a first step in evaluating the utility of hyperspectral reflectance and active light fluorescence for detecting frost damage to wheat during its reproductive phase. Two experiments were conducted immediately after the first observation of frost damage, (i) in 2006, five plots in an existing trial were opportunistically subdivided to take spectral reflectance measurements on frost damaged plants along with yield measurements, and (ii) in 2015, a transect across 31 rows within a commercial paddock was established to evaluate spectral reflectance, fluorometer measurements, and yield along a gradient from non-frosted to frost damaged plants. The results of the hyperspectral reflectance data appeared variable in response across the two experimental sites where frost was observed in-crop. In 2006, hyperspectral-derived indices showed significant differences (P < 0.05) between measurements of frosted and non-frosted canopies, but this was not the case for observations taken in 2015, where the mean response was reversed between experimental sites for several of the indices. In contrast, fluorometer measurements in the 2015 trial resulted in higher correlations with yield and observed frost damage compared with the reflectance measurements. Seven of the nine fluorometer indices evaluated were correlated with yield (used as an indicator of frost damage) at P < 0.01. An index of compounds which absorbs at 375 nm, FLAV, had the best correlation coefficients of 0.91 and 0.90 for the two dates in 2015. The fluorescence index FLAV was selected to evaluate whether it could be used to classify the canopy as frost affected or not, using discriminant analysis for the 2015 transect data. The overall classification accuracy, defined as the number of correctly classified measurements (57) divided by the total number (62) was 92%. The present study was not able to provide insight into how rapidly the sensors could detect frost damage before detection with the naked eye, as the survey data constituted a transect based on early visual symptoms, however this study does provide important insight into what sensors and/or indices may be sensitive to ‘seeing’ early frost damage in-crop. The next steps, which build on this work and need to be resolved are (i) what is the nominal scale of measurements required, and for which portions of the plant canopy? (ii) How robust (over space and time) are any relationships between frost damage and index response? (iii) Can frost damage be detected before the onset of visual damage?

Insecticidal seed treatments are used commonly worldwide to protect seedlings against root feeding insects. Organophosphate insecticides that have been used for seed treatments are being phased out and replaced with neonicotinoid insecticides. Concerns about the environmental impact of neonicotinoids have prompted a search for alternatives. Microbial insecticides are a biological alternative for seed treatments to target root feeding insects. Six field trials with organophosphate granules (diazinon, chlorpyrifos), neonicotinoid seed treatment (clothianidin) and microbial (Serratia entomophila) seed treatment targeting grass grub, a New Zealand scarab pest, were conducted in wheat crops at several sites over 4 years (2012–2015). Sites were selected each year that had potentially damaging populations of grass grub present during the trials. Untreated seeds led to significant losses of plants and wheat yield due to lower seedling establishment and ongoing plant losses from grass grub damage. Insecticide and microbial treatments increased plant survival in all trials compared with untreated seeds. Better plant survival was associated with higher yields from the insecticide treatments in four out of six trials. Neonicotinoid seed treatment alone gave similar yield increases to combined neonicotinoid seed treatment and organophosphate granules. Microbial seed treatment with S. entomophila gave similar yield increases to insecticide treatments in two out of six trials. Seed treatment with S. entomophila is an alternative for grass grub control; however, development of a commercial product requires effective scale-up of production, further research to improve efficacy, and viability of the live bacteria needs to be maintained on coated seed.

Post-anthesis water stress is a major limitation to wheat grain yield globally. Understanding the nature of gene action of yield related traits under post-anthesis water stress will help to breed stress-resilient genotypes. Four bread wheat genotypes having varying degree of drought tolerance were crossed in a full-diallel fashion and the resultant crosses along with the parental genotypes, were subjected to water stress after the onset of anthesis in order to investigate their comparative performance and nature of gene action. Parental genotypes Babax (B) and Westonia (W) performed better compared with C306 (C) and Dharwar Dry (D) with respect to relative reduction in grain yield and related traits under stressed condition. Direct cross B × D and reciprocal cross W × C were more tolerant to water stress, while cross between C306 and Dharwar Dry, either direct or reciprocal, produced more sensitive genotypes. Combining ability analysis revealed that both additive and non-additive gene action were involved in governing the inheritance of the studied traits, with predominance of non-additive gene action for most of the traits. Among the parents, Babax and Westonia were better combiners for grain yield under stress condition. B × D in stressed condition, and C × W in both stressed and stress-free conditions, were the most suitable specific crosses. Moreover, specificity of parental genotypes as female parents in cross combination was also evident from the significant reciprocal combining ability effects of certain traits. Low to medium narrow sense heritability and high broad sense heritability were observed for most of the studied traits in both well watered and water stress conditions. The results of the study suggested that specific cross combinations with high specific combining ability involving better performing parents with high general combining ability may generate hybrids as well as segregating populations suitable for further breeding programs.

To get a comprehensive view of drought tolerance mechanisms, the influence of water deficit stress on antioxidative capacity due to scavenging of free radicals and ability to maintain reduced cell state was investigated in roots, nodules, leaves, pod wall and seeds of two chickpea cultivars differing in rooting behaviour. ICC4958 (deep rooted) possessed better ability to combat water deficit-induced oxidative stress relative to ILC3279 (shallow rooted) as revealed by increase in total phenol, reducing power, ferric reducing ability and capacity to scavenge 2,2-Diphenyl-1-picryl hydrazyl (DPPH) and OH free radicals. Effect of water deficit stress on photosynthetic pigments of these cultivars was also studied. The investigation revealed that the influence of water stress in enhancing antioxidative capacity was most prominent in roots of ICC4958 among all other tissues as revealed by increased total phenols, DPPH and OH free radical scavenging activity and total reducing power under stress. However, roots of ILC3279 suffered a decrease in total phenolic content, total reducing power and DPPH free radical scavenging activity under prolonged stress, which was reflected in reduced antioxidative defence in reproductive tissues like decreased reducing power in pod wall and ferric-reducing antioxidant power ability in seeds.

Phytophthora root rot (PRR) caused by Phytophthora sojae, is one of the most destructive soybean diseases. The deployment of resistant cultivars is an important disease management strategy. To this aim, the development of a fast and effective method to evaluate soybean resistance to P. sojae is strategic. In this study, a detached-petiole inoculation technique was developed and its reliability was verified in soybean cultivars and segregant populations for PRR resistance. The detached-petiole and hypocotyl inoculation methods were used to assess the resistance of soybean cultivars, the F₂ population of a Zhonghuang47 × Xiu94-11 cross, and the derived F_2:3 population. The reactions of 13 analysed cultivars to three P. sojae isolates were consistent between the two inoculation techniques. The reactions of the F₂ and F_2:3 populations to isolate PsMC1 were 95.20% similar between the two inoculation methods. The segregation of the resistance and susceptibility fit a 3 : 1 ratio. Our results suggest that the detached-petiole technique is a reliable method, and reveal that the PRR resistance in Xiu94-11 is controlled by a single dominant gene. The phenotypic ratios of the tested Jikedou2 × Qichadou1 F₂ population using the detached-petiole inoculation technique fit a 3 : 1 ratio (Resistance : Susceptibility). This demonstrated that Qichadou1 contains a single dominant gene conferring resistance to P. sojae. Our new detached-petiole inoculation technique is effective, reliable, non-destructive to the plant, and does not require an excessive amount of seeds. It may be suitable for the largescale screening of soybean resistance to multiple P. sojae isolates.

Basal and canopy cover of sown and unsown species in swards sown with six species mixtures were assessed monthly from autumn 2010 to spring 2014, to test the hypotheses that (a) sowing an alternative pasture base, or (b) increasing the complexity of the sown mix, improves persistence and reduces weed ingress in temperate summer-dry dairy pastures. Treatments comprised either perennial ryegrass (Lolium perenne L.) infected with AR1 endophyte or tall fescue (Schedonorus arundinaceus (Schreb.) Dumort.) infected with Max P endophyte to which were added either a legume (‘standard’, 2-species mix), a legume and two forage herbs (‘herbs’, 4-species), or three legumes, two forage herbs and two grasses (‘complex’, 8-species). In the first year, basal and canopy cover of sown species were higher in perennial ryegrass- than tall fescue-based swards, and basal cover of sown species was higher and the percentage bare ground lower in the ‘standard’ (50%) than ‘herbs’ and ‘complex’ swards (42%). By the final year, basal cover of sown species (25%), unsown species (28%), and percentage bare ground (47%) were similar in all six treatments. Although establishment was greater in perennial ryegrass than tall fescue-based swards and in the ‘standard’ than in the ‘herbs’ and ‘complex’ mixtures, the loss of sown species in these treatments was greater. The decline in basal cover of sown species was –27% in the standard treatment, –16% averaged over the ‘complex’ and ‘herbs’ treatment, –24% in perennial ryegrass-based swards and –15% in tall fescue-based swards. The results are contrary to both hypotheses with respect to weed ingress. However, support was provided for the hypotheses in the greater persistence (smaller decline over time in basal cover) in tall fescue than ryegrass-based swards, and ‘herbs’ and ‘complex’ than ‘standard’ mixtures.

Waterlogging is a stress of increasing importance for pastures as a consequence of global climate change. We evaluated the impact of waterlogging on four forage grasses with alleged differential tolerance, emphasising not only responses during the stress but also their reported ability to recover from it. To do this, 42-day plants of Dactylis glomerata, Bromus catharticus, Festuca arundinacea and Phalaris aquatica were subjected to 15-day waterlogging, followed by a subsequent 15-day recovery period. Shoot and root growth (i.e. RGR) during both periods, in addition to net photosynthesis and stomatal conductance rates during waterlogging were assessed. Sensitivity exhibited by D. glomerata and B. catharticus during waterlogging was related to growth arrest of roots – but not of shoots – along with a progressive fall in stomatal conductance and net photosynthesis. The injury during waterlogging preceded a negligible growth of shoots and roots, only evident during recovery in both species. By contrast, P. aquatica exhibited unaltered root RGR and promoted shoot RGR with no impact on leaf gas exchange during waterlogging; whereas F. arundinacea showed intermediate tolerance as root RGR was reduced during waterlogging, with stomatal conductance, net photosynthesis and shoot RGR remaining unaffected. These latter two species fully regained shoot and root RGR during recovery. So, P. aquatica and F. arundinacea seem more suitable for prone-to-flood lowlands, whereas to be conclusive about waterlogging tolerance, it is necessary to examine plant recovery as shown in D. glomerata and B. catharticus.

Centaurea balsamita is a problematic and invasive weed of agricultural fields in western Iran. This study was conducted to determine the effect of different environmental factors on germination and seedling emergence of this weed species. Results revealed that seed germination occurred over a wide range of temperatures (from 5°C to 35°C) with the highest germination at 25°C. Seed germination of C. balsamita was similar between light and dark conditions. Germination decreased with increased in water stress levels, but some seeds were capable of germinating at –1.4 MPa osmotic potential. Seed germination was sensitive to salt stress and complete inhibition occurred at 150 mM sodium chloride. Seed germination of C. balsamita occurred over a pH range of 4–10 with lowest seed germination at pH 4. Seed germination was inhibited by increasing concentrations of potassium nitrate. No seedlings emerged when seeds were buried in the soil at depths greater than 6 cm, suggesting that using a sweep cultivator in crops and deep tillage would be beneficial in managing C. balsamita. The ability of C. balsamita to germinate under a wide range of temperature regimes and high levels of osmotic potential shows that this weed is well adapted to invade other cropping regions, especially rain-fed fields in western Iran.