A Novel Correction Methodology to Improve the Performance of a Low-Cost Hyperspectral Portable Snapshot Camera.

The development of spectral sensors (SSs) capable of retrieving spectral information have opened new opportunities to improve several environmental and agricultural practices, e.g., crop breeding, plant phenotyping, land use monitoring, and crop classification. The SSs are classified as multispectral and hyperspectral (HS) based on the number of the spectral bands resolved and sampled during data acquisition. Large-scale applications of the HS remain limited due to the cost of this type of technology and the technical difficulties in hyperspectral data processing. Low-cost portable hyperspectral cameras (PHCs) have been progressively developed; however, critical aspects associated with data acquisition and processing, such as the presence of spectral discontinuities, signal jumps, and a high level of background noise, were reported. The aim of this work was to analyze and improve the hyperspectral output of a PHC Senop HSC-2 device by developing a general use methodology. Several signal gaps were identified as falls and jumps across the spectral signatures near 513, 650, and 930 nm, while the dark current signal magnitude and variability associated with instrumental noise showed an increasing trend over time. A data correction pipeline was successfully developed and tested, leading to 99% and 74% reductions in radiance signal jumps identified at 650 and 830 nm, respectively, while the impact of noise on the acquired signal was assessed to be in the range of 10% to 15%. The developed methodology can be effectively applied to other low-cost hyperspectral cameras.

Low-Cost Hyperspectral Imaging to Detect Drought Stress in High-Throughput Phenotyping.

Recent developments in low-cost imaging hyperspectral cameras have opened up new possibilities for high-throughput phenotyping (HTP), allowing for high-resolution spectral data to be obtained in the visible and near-infrared spectral range. This study presents, for the first time, the integration of a low-cost hyperspectral camera Senop HSC-2 into an HTP platform to evaluate the drought stress resistance and physiological response of four tomato genotypes (770P, 990P, Red Setter and Torremaggiore) during two cycles of well-watered and deficit irrigation. Over 120 gigabytes of hyperspectral data were collected, and an innovative segmentation method able to reduce the hyperspectral dataset by 85.5% was developed and applied. A hyperspectral index (H-index) based on the red-edge slope was selected, and its ability to discriminate stress conditions was compared with three optical indices (OIs) obtained by the HTP platform. The analysis of variance (ANOVA) applied to the OIs and H-index revealed the better capacity of the H-index to describe the dynamic of drought stress trend compared to OIs, especially in the first stress and recovery phases. Selected OIs were instead capable of describing structural changes during plant growth. Finally, the OIs and H-index results have revealed a higher susceptibility to drought stress in 770P and 990P than Red Setter and Torremaggiore genotypes.

The effect of summer drought on the yield of Arundo donax is reduced by the retention of photosynthetic capacity and leaf growth later in the growing season.

BACKGROUND AND AIMS: The development of Arundo donax as a biomass crop for use on drought-prone marginal lands in areas with warm to hot climates is constrained by the lack of variation within this species. We investigated the effect of morphological and physiological variation on growth and tolerance to drought under field conditions in three ecotypes of A. donax collected from habitats representing a climate gradient: a pre-desert in Morocco, a semi-arid Mediterranean climate in southern Italy and a warm sub-humid region of central Italy. METHODS: The three A. donax ecotypes were grown under irrigated and rain-fed conditions in a common garden field trial in a region with a semi-arid Mediterranean climate. Physiological and morphological characteristics, and carbohydrate metabolism of the ecotypes were recorded to establish which traits were associated with yield and/or drought tolerance. KEY RESULTS: Variation was observed between the A. donax ecotypes. The ecotype from the most arid habitat produced the highest biomass yield. Stem height and the retention of photosynthetic capacity later in the year were key traits associated with differences in biomass yield. The downregulation of photosynthetic capacity was not associated with changes in foliar concentrations of sugars or starch. Rain-fed plants maintained photosynthesis and growth later in the year compared with irrigated plants that began to senescence earlier, thus minimizing the difference in yield. Effective stomatal control prevented excessive water loss, and the emission of isoprene stabilized photosynthetic membranes under drought and heat stress in A. donax plants grown under rain-fed conditions without supplementary irrigation. CONCLUSIONS: Arundo donax is well adapted to cultivation in drought-prone areas with warm to hot climates. None of the A. donax ecotypes exhibited all of the desired traits consistent with an 'ideotype'. Breeding or genetic (identification of quantitative trait loci) improvement of A. donax should select ecotypes on the basis of stem morphology and the retention of photosynthetic capacity.

Moderate Drought Stress Induces Increased Foliar Dimethylsulphoniopropionate (DMSP) Concentration and Isoprene Emission in Two Contrasting Ecotypes of Arundo donax.

The function of dimethylsulphoniopropionate (DMSP) in plants is unclear. It has been proposed as an antioxidant, osmolyte and overflow for excess energy under stress conditions. The formation of DMSP is part of the methionine (MET) pathway that is involved in plant stress responses. We used a new analytical approach to accurately quantify the changes in DMSP concentration that occurred in two ecotypes of the biomass crop Arundo donax subject to moderate drought stress under field conditions. The ecotypes of A. donax were from a hot semi-arid habitat in Morocco and a warm-humid environment in Central Italy. The Moroccan ecotype showed more pronounced reductions in photosynthesis, stomatal conductance and photochemical electron transport than the Italian ecotype. An increase in isoprene emission occurred in both ecotypes alongside enhanced foliar concentrations of DMSP, indicative of a protective function of these two metabolites in the amelioration of the deleterious effects of excess energy and oxidative stress. This is consistent with the modification of carbon within the methyl-erythritol and MET pathways responsible for increased synthesis of isoprene and DMSP under moderate drought. The results of this study indicate that DMSP is an important adaptive component of the stress response regulated via the MET pathway in A. donax. DMSP is likely a multifunctional molecule playing a number of roles in the response of A. donax to reduced water availability.

Flavonol content and biometrical traits as a tool for the characterization of "Cipolla di Giarratana": a traditional Sicilian onion landrace.

"Cipolla di Giarratana", a locally cultivated white onion landrace, is listed as an item in the 'List of Traditional Agro-food Products' of the Italian Department for Agriculture and itemised as 'slow food presidium' by the Slow Food Foundation. Ten local accessions were investigated for their biomorphological and biochemical characteristics in five experimental locations. High-performance liquid chromatography coupled with diode array detection and electron spray-mass spectrometry (HPLC/DAD/ESI-MS) was used to identify the phenolic profile and quantify phenolic content in bulbs: quercetin, quercetin 3,4' di-O-glucoside and quercetin 4'-O-glucoside were detected as major components. The 'Cipolla di Giarratana' landrace is characterised by a high bulb weight (436g) and high diameter (11cm). The total flavonols content ranged between 68 and 408mgkg(-1) bulb fresh weight in nine of the 10 collected accessions. The opportunity of considering flavonol patterns as chemotaxonomic descriptors in order to characterise onion germplasm is also discussed.

Re-evaluation of traditional Mediterranean foods. The local landraces of 'Cipolla di Giarratana' (Allium cepa L.) and long-storage tomato(Lycopersicon esculentum L.): quality traits and polyphenol content.

BACKGROUND: The heightened consumer awareness for food safety is reflected in the demand for products with well-defined individual characteristics due to specific production methods, composition and origin. In this context, of pivotal importance is the re-evaluation of folk/traditional foods by properly characterizing them in terms of peculiarity and nutritional value. The subjects of this study are two typical Mediterranean edible products. The main morphological, biometrical and productive traits and polyphenol contents of three onion genotypes ('Cipolla di Giarratana', 'Iblea' and 'Tonda Musona') and three long-storage tomato landraces ('Montallegro', 'Filicudi' and 'Principe Borghese') were investigated. RESULTS: Sicilian onion landraces were characterized by large bulbs, with 'Cipolla di Giarratana' showing the highest bulb weight (605 g), yield (151 t ha(-1)) and total polyphenol content (123.5 mg kg(-1)). Landraces of long-storage tomato were characterized by low productivity (up to 20 t ha(-1)), but more than 70% of the total production was obtained with the first harvest, allowing harvest costs to be reduced. High contents of polyphenols were found, probably related to the typical small fruit size and thick skin characterizing these landraces. CONCLUSION: The present study overviews some of the most important traits that could support traditional landrace characterization and their nutritional value assessment.

Bio-based and biodegradable plastics for use in crop production.

The production and management of crops uses plastics for many applications (e.g., low tunnels, high tunnels, greenhouses, mulching, silage bags, hay bales, pheromone traps, coatings of fertilizers or pesticides or hormones or seeds, and nursery pots and containers for growing transplants). All these applications have led some authors to adopt the term "plasticulture" when discussing the use of plastic materials in agriculture and related industries. Unfortunately, the sustainability of this use of plastics is low, and renewability and degradability have become key words in the debate over sustainable production and utilization of plastic. Recently, researchers and the plastics industry have made strong efforts (i) to identify new biopolymers and natural additives from renewable sources that can be used in plastics production and (ii) to enhance the degradability (biological or physical) of the new ecologically sustainable materials. In the present review, we describe the main research results, current applications, patents that have been applied for in the last two decades, and future perspectives on sustainable use of plastics to support crop production. The article presents some promising patents on bio-based and biodegradable plastics for use in crop production.

Recent patents on the extraction of carotenoids.

This article reviews the patents that have been presented during the last decade related to the extraction of carotenoids from various forms of organic matter (fruit, vegetables, animals), with an emphasis on the methods and mechanisms exploited by these technologies, and on technical solutions for the practical problems related to these technologies. I present and classify 29 methods related to the extraction processes (physical, mechanical, chemical, and enzymatic). The large number of processes for extraction by means of supercritical fluids and the growing number of large-scale industrial plants suggest a positive trend towards using this technique that is currently slowed by its cost. This trend should be reinforced by growing restrictions imposed on the use of most organic solvents for extraction of food products and by increasingly strict waste management regulations that are indirectly promoting the use of extraction processes that leave the residual (post-extraction) matrix substantially free from solvents and compounds that must subsequently be removed or treated. None of the reviewed approaches is the best answer for every extractable compound and source, so each should be considered as one of several alternatives, including the use of a combination of extraction approaches.

Gas exchange and photosynthetic water use efficiency in response to light, CO2 concentration and temperature in Vicia faba.

Light and temperature-response curves and their resulting coefficients, obtained within ecophysiological characterization of gas exchanges at the leaf level, may represent useful criteria for breeding and cultivar selection and required tools for simulation models aimed at the prediction of potential plant behaviour in response to environmental conditions. Leaf-scale gas exchanges, by means of an IRGA open-flow system, were measured in response to light intensity (8 levels from 0 up to 2000 micromol m(-2) s(-1)), CO(2) concentrations (ambient-350 micromol mol(-1) and short-term enriched-700 micromol mol(-1)) and air temperature (from 7 up to 35 degrees C) on three Vicia faba L. genotypes, each representing one of the three cultivated groups: major, equina and minor. The net assimilation rate response to light intensity was well described by an exponential rise to max function. The short-term CO(2) enrichment markedly increased the values of light response curve parameters such as maximum photosynthetic rate (+80%), light saturation point (+40%) and quantum yield (+30%), while less homogenous behaviour was reported for dark respiration and light compensation point. For each light intensity level, the major and minor genotypes studied showed assimilation rates at least a 30% higher than equina. The positive effects of short-term CO(2) enrichment on photosynthetic water use efficiency (WUE) indicate a relevant advantage in doubling CO(2) concentration. In the major and minor genotypes studied, similar assimilation rates, but different WUE were observed. The optimum leaf temperature for assimilation process, calculated through a polynomial function, was 26-27 degrees C and no relevant limitations were observed in the range between 21 and 32 degrees C. Analysis at the single leaf level provided both rapid information on the variations in gas exchange in response to environmental factors and selection criteria for the screening of genotypes.