Prospects for plant defence activators and biocontrol in IPM - Concepts and lessons learnt so far

There is an urgent need to develop new interventions to manage pests because evolution of pesticide resistance and changes in legislation are limiting conventional control options for farmers. We investigated β-aminobutyric acid (BABA), jasmonic acid (JA) and fructose as possible plant defence activators against grey mould disease, . Botrytis cinerea, and root knot nematode, . Meloidogyne incognita. We also tested . Trichogramma achaeae parasitoid wasps and an antifeedant plant extract for biocontrol of the invasive tomato leafminer, . Tuta absoluta. BABA and JA enhanced resistance of tomato plants to . B. cinerea but neither treatment provided complete protection and the efficacy of treatment varied over time with BABA being more durable than JA. Efficacy was partly dependent on tomato cultivar, with some cultivars responding better to BABA treatment than others. Furthermore, treatment of tomato with BABA, JA and fructose led to partial suppression of . M. incognita egg mass development. Biocontrol agent, . T. achaeae, performance against . T. absoluta could be enhanced by adjusting the rearing conditions. Both attack rate and longevity were improved by rearing the parasitoids on . T. absoluta rather than on other insects. Finally, . Ajuga chamaepitys extract was shown to have significant antifeedant activity against . T. absoluta. Our findings suggest that there are potential new solutions for protection of crops but they are more complicated to deploy, more variable and require more biological knowledge than conventional pesticides. In isolation, they may not provide the same level of protection as pesticides but are likely to be more potent when deployed in combination in IPM strategies

Effects of sleep deprivation on neural functioning: an integrative review

Sleep deprivation has a broad variety of effects on human performance and neural functioning that manifest themselves at different levels of description. On a macroscopic level, sleep deprivation mainly affects executive functions, especially in novel tasks. Macroscopic and mesoscopic effects of sleep deprivation on brain activity include reduced cortical responsiveness to incoming stimuli, reflecting reduced attention. On a microscopic level, sleep deprivation is associated with increased levels of adenosine, a neuromodulator that has a general inhibitory effect on neural activity. The inhibition of cholinergic nuclei appears particularly relevant, as the associated decrease in cortical acetylcholine seems to cause effects of sleep deprivation on macroscopic brain activity. In general, however, the relationships between the neural effects of sleep deprivation across observation scales are poorly understood and uncovering these relationships should be a primary target in future research

Near infrared reflectance spectroscopy for estimating soil characteristics valuable in the diagnosis of soil fertility

Soil fertility diagnostics rely not only upon measurement of available nutrients but also upon the soil’s ability to retain these nutrients. Near-infrared reflectance spectroscopy (NIRS) is a rapid and non-destructive analytical technique which allows to simultaneously estimate standard soil characteristics and does not require use of chemicals. Previous studies showed that NIRS could be used in local contexts to predict soil properties. The main goal of our research is to build a methodological framework for the use of NIRS at a more global scale. The specific goals of this study were (i) to identify the best spectra treatment and processing –LOCAL versus GLOBAL regression- methods, (ii) to compare NIRS performances to standard chemical protocols and (iii) to evaluate the ability of NIRS to predict soil total organic carbon (TOC), total Nitrogen (TN), clay content and cationic exchange capacity (CEC) for a wide range of soil conditions. We scanned 1,300 samples representative of main soil types of Wallonia under crop, grassland or forest. Various sample preparations were tested prior to NIRS measurements. The most appropriate options were selected according to ANOVA analysis and multiple means comparisons of the spectra principal components. Fifteen pre-treatments were applied to a calibration set and the prediction accuracy was evaluated for GLOBAL and LOCAL modified partial least square (MPLS) regression models. The LOCAL MPLS calibrations showed very encouraging results for all the studied characteristics. On average, for crop soil samples, the prediction coefficient of variation (CVp) was close to 15% for TOC content, 7% for TN content, and 10% for clay content and CEC. The comparisons of repeatability and reproducibility of both NIRS and standard methods showed that NIRS is as reliable as reference methods. Prediction accuracy and technique repeatability allow the use of NIRS within the framework of the soil fertility evaluation and its replacement of standard protocols. LOCAL MPLS can be applied within global datasets, such as the International global soil spectral library. However, the performance of LOCAL MPLS is linked to the number of similar spectra in the dataset and more standard measurements are needed to characterize the least widespread soils