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CONTEXT Drought and extreme heat at flowering are common stresses limiting the yield of summer crops, which are likely to intensify and become more frequent as projected under climate change.OBJECTIVE This study explores the idea that adaptation to these stresses could be increased by sowing summer crops early in late winter or spring, to avoid the overlap with critical crop stages around flowering. Here we report on the impacts of early sowing i.e., in late winter and spring on sorghum crop and root growth and function (i.e., water use), and final grain yield.METHODS Two seasons of on-farm genotype (G) by environment (E) by management (M) sorghum experimentation were conducted in the Darling Downs region of Queensland, Australia. Each trial consisted of a factorial combination of three times of sowing (TOS, referred to as late winter, spring, and summer), two levels of irrigation, four plant populations, and six commercial genotypes. Treatments were replicated three times. Crop roots and shoot were sampled at the flag leaf stage for each TOS. Crop water use across the growing season was monitored using time-lapse electromagnetic induction (EMI) surveys. EMI was also used to calculate a root activity factor. Final grain yield and yield components were determined at maturity.RESULTS Results showed that TOS, irrigation levels, and their interactions significantly influenced crop root and shoot traits, water use, and yield, though results were not always consistent across seasons. In the first season which was dry and had large temperature contrasts between TOS, crop growth in the early sown crops was primarily limited by temperature. In contrast, the second season was much warmer and crop growth was instead primarily limited by water availability. Cold air and soil temperatures in the early sowing dates i.e., late winter and spring during the first season, lead to smaller crops with smaller rooting systems and root-to-shoot ratios, and roots having a larger average ro

CONTEXT. Drought and extreme heat at flowering are common stresses limiting the yield of summer crops. Adaptation to these stresses could be increased by sowing summer crops early in late winter or spring, to avoid the overlap with critical crop stages around flowering. Though little is known about the effects of cold weather on root growth, water use and final grain yield in sorghum. OBJECTIVE. To research the effects of cold conditions in early sowing sorghum on crop and root growth and function (i.e., water use), and final grain yield. METHODS. Two years of field experiments were conducted in the Darling and Eastern Downs region of Qld, Australia. Each trial consisted of three times of sowing (late winter, spring, and summer), two levels of irrigation (i.e., rainfed and supplementary irrigated), four plant population densities (3, 6, 9 and 12 pl m⁻²), and six commercial sorghum hybrids. Roots and shoots were sampled at the flag leaf stage on three times of sowing, two levels of irrigation, and three replications, for a single hybrid and a single plant population density (9pl m⁻²). Crop water use and functional root traits were derived from consecutive electromagnetic induction (EMI) surveys around flowering. At maturity crop biomass, yield and yield components were determined across all treatments. RESULTS. The combinations of seasons, times of sowing and levels of irrigation created large variations in growth conditions that affected the growth and production of the crops. Early sowing increased yield by transferring water use from vegetative to reproductive stages increasing water use efficiency (kg mm⁻¹ available water). The larger yields in the early and spring sown crops were associated to larger grain numbers, particularly in tillers. Cold temperatures in the early sowing times tended to produce smaller crops with smaller rooting systems, smaller root-to-shoot ratios, and larger average root diameters. Total root length and root length density increased wit

Context Evaluating the genotype (G) by management practice (M) interaction in agronomic experimentation is essential to help grain growers optimise the desired trait of interest (e.g. grain yield). However, the approach is complicated by interaction effects with environmental factors that differ across sites and seasons. Popular statistical methods for modelling the genotype by environment (G × E) interaction are limited as they neither provide a biological understanding of how environmental factors impact on the G × E interaction, nor assess how different management practices influence the G × E interaction. These limitations may be addressed by incorporating environmental covariates (ECs) into the modelling process to better explain why differences exist in the optimal genotype by management practice combination across environments. Objective A novel statistical methodology is proposed that incorporates ECs to explore genotype by environment by management practice (G × E × M) interactions in agronomic multi-environment trial studies. Methods A predictive linear mixed model is proposed that incorporates site and season specific ECs into a commonly used G × E interaction framework. The model is extended to include the effect of continuously varying agronomic management practices, whilst allowing for non-linear trait responses and complex variance structures. The methodology is applied to a multi-environment dataset exploring yield response to established plant density in a series of sorghum agronomy trials. Results Results indicated that the grain yield of sorghum genotypes would be optimised in environments that have (i) high total plant available water and photo-thermal quotient around flowering, (ii) low pre-flowering radiation and evapotranspiration and (iii) achieved flowering at an optimal time. Under this set of optimal G × E conditions, a high established plant density further optimised grain yield. Conclusions The proposed methodology successfully incorpora

Winter sown sorghum reduces the impact of heat and water stresses around flowering and increases cropping intensity, though, achieving uniform plant establishment remains challenging. Sowing sorghum in winter will require crops to uniformly germinate and emerge in soils which are cooler than the recommended >16ºC minimum daily temperature, during the driest time of the year. Prolonged emergence periods and reduced total emergence can decrease canopy uniformity with negative impacts on yield, crop management and cropping system intensity. Acceptable establishment percentages (>80%) were achieved for some site by seedlot combinations, though large differences in establishment rate between seedlots were observed. The differences in seedlot emerge rate were related to final establishment. This calls for seed vigour testing, novel seed production technologies, management of seedbed hydrothermal conditions and breeding programs for cold tolerance.

Early sown sorghum is a viable alternative for the Liverpool Plains of NSW. It is currently unknown if the longer vegetative period created by sowing into sub-optimal soil temperatures could affect water productivity. Water use was measured on an early (Agitator) and a late (MR Buster) maturing hybrid, sown in early and late spring and summer in 2018 and 2019 at 30, 60 (standard practice) and 120 thousand plants/ha. Crops sown very early into cooler soil conditions had lower water use than those sown at early and normal sowing times. There was a significant impact of time of sowing on grain yield, which was seasonally dependent. Water productivity for MR Buster was higher when grown at 30,000 plants/ha compared to the standard density and higher density. For Agitator, earlier sowing reduced water productivity. The potential of early sowing to increase yield and water productivity of sorghum needs assessment under additional seasons and environmental conditions.

Researching the management (M) of genotypes (G) in agronomic experimentation is essential to help farmers maximise grain yield, though the approach is complicated by interactions emerging from changing environmental (E) factors across sites and seasons. Available statistical methods for modelling the G×E interaction are limited as they do not provide a functional understanding of how environmental factors influence the G×E interaction, nor assess how different management practices (M) influence the G×E interaction. A predictive linear mixed model is proposed that incorporates site/season-specific environmental covariates into a standard G×E interaction framework. The model is extended to include continuously varying agronomic management practices whilst allowing for non-linear trait responses and complex variance structures. The methodology was applied to a multi-environment data set associated with GRDC’s optimising sorghum agronomy program. The analysis identified key environmental drivers and management strategies that explained the G×E×M interaction, enhancing the biological understanding of the analysis results and allowing for the development of more robust recommendations for agronomic practices.

The idea that “Yield is King” fails to acknowledge that what matters most to farmers is farm profits and risk, rather than yield. This is because decisions made in one season will affect options and crop performance over the next few years. Therefore, quantifying the longer-term impacts of innovation adoption is important. We used the Agricultural Production Simulation model (APSIM) to simulate and investigate the implications of adopting rain-fed winter sown sorghum in the Australian northern grains region. Results indicate that within a crop rotation early-planted sorghum will tend to decrease median sorghum crop yields but increase the following winter crop yields. This appears to have a marginal economic effect in Breeza and Dalby but encouraging results in Emerald. The inclusion of chickpea within the rotation increased returns in the best seasons with little change to downside risks in poor seasons.

History shows that transformational changes in agriculture are rarely associated with the adoption of single innovations. It has been argued that transformative changes in agriculture have usually resulted from the incremental adoption of complementary technologies, and result in ongoing increases in yield from improvements from breeding and agronomy – though gains in productivity remain piece meal, insufficient and primarily confused with adoption processes. Here we propose that there is a role and need to design research that aims to be more transformative, likely to have larger than the ongoing or incremental gains, and that can be achieved in shorter periods of time. This argument is discussed by summarising the results of a four-year cross-agency research program conducted across Eastern Australia that tested crop designs of winter sown sorghum (WSS). The innovation is a systems adaptation with the potential to produce gains in productivity and farmer profits beyond what is the incremental or ongoing yield gain – though impact will still be dependent on adoption rates.

Grain sorghum yield is often reduced by heat and water stress during critical growth stages around anthesis when planted in the traditional sowing window. Sorghum sown during late winter or early spring can flower before these stresses develop, though reduced plant establishments due to sub optimal soil temperatures and the likelihood of frost damage need to be managed. Two years of experiments at Mungindi, Moree and the Liverpool Plains in Northern NSW compared sowing time effect on plant establishment, date of anthesis and grain yield. Sorghum can be established in sub-optimal temperatures (<16°C) if seedbed moisture is available but losses of 10-30% need to be factored into sowing rates. The overlap between flowering and heat stress was minimised by ‘winter’ or early spring sowing. Grain yield was maintained or improved by planting earlier compared to traditional sowing times.

Identifying optimum combinations of genotype (G) and agronomic management (M) i.e. crop design, to match the environment (E) i.e. site and expected seasonal conditions, is a useful concept to maximise crop yields and farmers’ profits. However, operationalising the concept requires practitioners to understand the likelihood of different E outcomes and GxM combinations that would maximise yields while managing risks. Here we propose and demonstrate an analysis framework to inform crop designs (GxM) at the time of sowing of a dryland maize crop, that combines data sets from multi-environment field experimentation and crop simulation modelling, and that accounts for risk preference. A network of replicated, G by M on-farm and on-research station trials (n = 10), conducted across New South Wales and Queensland, Australia, over three seasons (2014–2016) was collected. The trials consisted of combinations of commercial maize hybrids, sown at a range of plant densities and row configurations producing site average yields (Environment-yield) that varied between 1576 and 7914 kg ha−1. Experimental data were used to test the capacity of APSIM-Maize 7.10 to simulate the experimental results, and to in-silico create a large synthetic data set of multi-E (sites x seasons) factorial combination of crop designs. Data mining techniques were applied on the synthetic data set, to derive a probabilistic model to predict the likely Environment-yield and associated risk from variables known at sowing, and to derive simple “rules of thumb” for farmers that discriminate high and low yielding crop designs across the lower, middle and upper tercile of the predicted Environment-yields. Four risk profiles are described, a “Dynamic” (i.e. each year the farmer would adopt a crop design based on the predicted Environment-yield tercile and corresponding “rules of thumb”), “High rewards seeker” (i.e. each year the farmer would adopt the crop design that optimises yield for the higher tercile of Env

Water and heat stressors during flowering are predominant limitations of dryland sorghum yields across Australia’s north-eastern cropping zone. Crops sown early could flower before seasonal heatwaves, but the seed must uniformly germination and emerge at soil temperatures between approximately 10 to 15 °C. Furthermore, chemical coatings applied to commercial hybrid seed lots effectively protected the developing crop from pest, disease and herbicide damage but the combined influence of low temperatures and seed coatings on germination of hybrid sorghum seed batches is unknown. In this experiment, germination dynamics were modelled for 10 commercial sorghum hybrid-seed lots (with or without seed coating of a.i. thiamethoxam, oxabetrinil and thiram) incubated at continuous temperatures ranging from 9.4 to 46.1 °C. Results also show commercial seed treatments negatively affect final germination proportion especially at sub- and supra-optimal temperatures. Some hybrid-seed lots in current experiment were more sensitive to seed coatings at either sub- or supra-optimal temperatures regardless of seed germination capability (i.e., germination proportion at 25 °C). Seeds took 5 days to reach 50% germination (t50) at 9.4 °C but germinated within 24 h at constant temperatures between 20 and 40 °C. The spread of germination (time between 10 and 90% germination) increased from 0.5 days at 30 °C to 3.8 days at 9.4 °C. Therefore, some hybrid-seedlots are suited to early sowing because they can maintain high germination proportion (>90%) even at soil temperatures (9.4 °C) as long as the seedbed remains moist for a least 12 days. Research continues identify the basis of cold tolerance in some-hybrid seedlots.

Multi-environment trials (MET) (n = 15 environments, E) combining most commercially available sorghum hybrids (G), and managements (M) (i.e. plant density and configuration combinations), were run across the Northern Grains Region of Australia during the 2014/15 and 2015/16 seasons to (i) characterise the yield potential and yield stability of the different hybrids; and (ii) derive simple crop design (G x M) rules that maximise yield across different environments. Irrespective of the environment yield, most modern hybrids out-yielded the industry standard (MR-Buster). There were a small number of hybrids whose yield stability indicated they were more responsive than MR-Buster to changes in the environment. However, many hybrids had a lower yield stability, suggesting their yield is less likely to change across environments relative to the industry standard. Recursive partitioning showed that in all sites high initial soil water and narrow row spacing led to greater yields. In low yielding sites hybrid characteristics, especially high yield potential, lead to improved productivity. The main conclusion from this work is that in sorghum what really matters is not just agronomy, but to understand how to match hybrids and agronomy to site and seasonal conditions.

Artículo de revista, La Financial Services Authority (FSA) tiene cuatro objetivos establecidos de conformidad con la Ley de Mercados y Servicios Financieros promulgada en el año 2000, que es la normativa del Reino Unido por la que se rige esta institución. Estos objetivos se refieren al mantenimiento de la confianza de los mercados, la protección de los consumidores, la sensibilización de la opinión pública y la reducción de los delitos financieros. Sin embargo, aun cuando la FSA pretende prevenir o atenuar numerosas maneras de perjudicar a los consumidores, sus objetivos legales no le exigen impedir todas las quiebras de empresa y fallos de conducta. El enfoque regulador de la FSA, derivado de la legislación y basado en el análisis económico, se fundamenta en la opinión de que un régimen que tratara de evitar todas las quiebras y las pérdidas tendría efectos adversos sobre la competencia y la innovación en los mercados financieros, generaría incentivos perversos y sería imposible de conseguir en la práctica. Este artículo examina la lógica del enfoque de «quiebras ocasionales» (non-zero failure approach) de la FSA. En primer lugar, analiza la base jurídica de la regulación de la FSA y cómo el citado enfoque se encuentra implícito en la normativa que estableció este organismo. Posteriormente examina cómo la FSA procura cumplir con sus obligaciones legales tratando de corregir los fallos de mercado que impiden la consecución de sus objetivos. Estos fallos son, fundamentalmente, la asimetría de la información entre los participantes en los mercados y las externalidades, en concreto las que pueden ocasionar una situación de riesgo sistémico. El enfoque regulador de la FSA reconoce, sin embargo, que se producirán fallos como parte del proceso de mercado. En caso de eliminarse esta posibilidad, ni las empresas ni los consumidores tendrían incentivos para actuar con prudencia y, con el tiempo, ello incrementaría la probabilidad de que se produjeran fallos importantes, y los costes para las em