Towards more precise sugar beet management based on geostatistical analysis of spatial variability within fields

Within-field variation in sugar beet yield and quality was investigated in three commercial sugar beet fields in the east of England to identify the main associated variables and to examine the possibility of predicting yield early in the season with a view to spatially variable management of sugar beet crops. Irregular grid sampling with some purposively-located nested samples was applied. It revealed the spatial variability in each sugar beet field efficiently. In geostatistical analyses, most variograms were isotropic with moderate to strong spatial dependency indicating a significant spatial variation in sugar beet yield and associated growth and environmental variables in all directions within each field. The Kriged maps showed spatial patterns of yield variability within each field and visual association with the maps of other variables. This was confirmed by redundancy analyses and Pearson correlation coefficients. The main variables associated with yield variability were soil type, organic matter, soil moisture, weed density and canopy temperature. Kriged maps of final yield variability were strongly related to that in crop canopy cover, LAI and intercepted solar radiation early in the growing season, and the yield maps of previous crops. Therefore, yield maps of previous crops together with early assessment of sugar beet growth may make an early prediction of within-field variability in sugar beet yield possible. The Broom’s Barn sugar beet model failed to account for the spatial variability in sugar yield, but the simulation was greatly improved when corrected for early canopy development cover and when the simulated yield was adjusted for weeds and plant population. Further research to optimize inputs to maximise sugar yield should target the irrigation and fertilizing of areas within fields with low canopy cover early in the season.

Fungicide-resistance management tactics: impacts on Zymoseptoria tritici populations

Azoles and Succinate Dehydrogenase Inhibitors (SDHIs) are the main fungicides available for septoria tritici blotch control, causal agent Zymoseptoria tritici. Decline in azole sensitivity, in combination with European legislation, poses a threat to wheat production in Ireland. Azole fungicides select CYP51 mutations differentially; it was hypothesised that using combinations of azoles could be an effective anti-resistance tool. Naturally inoculated field experiments were carried out in order to understand the impacts of using combinations of azoles, epoxiconazole and metconazole, on azole sensitivity. Approximately 3700 isolates were isolated and their sensitivity to both azoles analysed. Findings showed that limiting the number of applications, by alternating each fungicide, slowed selection for reduced azole sensitivity. Limiting azole use by reducing doses did not reduce selection for decreased azole sensitivity. Although not complete, cross-resistance was observed between the two azoles, which will lead to general reduction in azole sensitivity. A sub-selection of isolates from each treatment at each location were analysed for changes in the CYP51 gene. Sequence analysis identified 49 combinations of mutations in the CYP51 gene, and three different inserts in the CYP51 promoter. Intragenic recombination also featured in these populations. Baseline studies of five new SDHIs were carried out on 209 naturally infected, non-SDHI-treated isolates. With the exception of fluopyram, cross-resistance was apparent between the SDHIs. Analysis of 2300 isolates found that when compared to the solo products, mixing the SDHI isopyrazam and the azole epoxiconazole increased epoxiconazole sensitivity, but had no apparent effect on isopyrazam sensitivity. SDHI resistance-conferring mutations were absent in the baseline and experimental isolates. As long as azoles are used, Z. tritici populations will continue to evolve towards resistance. Combining different modes-of-action, SDHIs and multi-sites, with azoles will relieve some of that selective pressure. To get the best out of available fungicides, they should be used in combination with host resistance and good crop management practices.

The three faces of bounded reliability: Alfred Chandler and the micro-foundations of management theory

Alfred Chandler, the celebrated business historian, provided detailed descriptions of the reasons for failed human commitments and the managerial tools needed to prevent/remediate such failings in the context of large business firms. Chandler's historical narrative identifies three distinct “faces” of bounded reliability—opportunism, benevolent preference reversal, and identity-based discordance—as the main drivers of commitment failure. Adopting bounded reliability (BRel) as a micro-foundation in management studies will raise the quality and relevance of scholarly recommendations to improve managerial decision making and action, because analysis of BRel challenges closely mirrors the real-world problems facing practicing managers.

Can milk proteins be a useful tool in the management of cardiometabolic health? An updated review of human intervention trials

The prevalence of cardiometabolic diseases is a significant public health burden worldwide. Emerging evidence supports the inverse association between greater dairy consumption and reduced risk of cardiometabolic diseases. Dairy proteins may have in important role in the favourable impact of dairy on human health such as blood pressure (BP) control, blood lipid and glucose control. The purpose of this review is to update and critically evaluate the evidence on the impacts of casein and whey protein in relation to metabolic function. Evidence from acute clinical studies assessing postprandial responses to milk protein ingestion suggests benefits on vascular function independent of BP, as well as improvement in glycaemic homeostasis. Chronic interventions have been less conclusive, with some showing benefits and others indicating a lack of improvement in vascular function. During chronic consumption BP appears to be lowered and both dyslipidaemia and hyperglacaemia seems to be controlled. Limited number of trials investigated the effects of dairy proteins on oxidative stress and inflammation. The beneficial changes in cardiometabolic homeostasis are likely mediated through improvements in insulin resistance, however to gain more detailed understanding on the underlying mechanism of milk proteins warrants further research. The incorporation of meals enriched with dairy protein in the habitual diet may result in the beneficial effects on cardiometabolic health. Nevertheless, future well-designed, controlled studies are needed to investigate the relative effects of both casein and whey protein on BP, vascular function, glucose homeostasis and inflammation.