Impact of Irrigation Strategies on Tomato Root Distribution and Rhizosphere Processes in an Organic System.

Root exploitation of soil heterogeneity and microbially mediated rhizosphere nutrient transformations play critical roles in plant resource uptake. However, how these processes change under water-saving irrigation technologies remains unclear, especially for organic systems where crops rely on soil ecological processes for plant nutrition and productivity. We conducted a field experiment and examined how water-saving subsurface drip irrigation (SDI) and concentrated organic fertilizer application altered root traits and rhizosphere processes compared to traditional furrow irrigation (FI) in an organic tomato system. We measured root distribution and morphology, the activities of C-, N-, and P-cycling enzymes in the rhizosphere, the abundance of rhizosphere microbial N-cycling genes, and root mycorrhizal colonization rate under two irrigation strategies. Tomato plants produced shorter and finer root systems with higher densities of roots around the drip line, lower activities of soil C-degrading enzymes, and shifts in the abundance of microbial N-cycling genes and mycorrhizal colonization rates in the rhizosphere of SDI plants compared to FI. SDI led to 66.4% higher irrigation water productivity than FI, but it also led to excessive vegetative growth and 28.3% lower tomato yield than FI. Our results suggest that roots and root-microbe interactions have a high potential for coordinated adaptation to water and nutrient spatial patterns to facilitate resource uptake under SDI. However, mismatches between plant needs and resource availability remain, highlighting the importance of assessing temporal dynamics of root-soil-microbe interactions to maximize their resource-mining potential for innovative irrigation systems

Use of time-resolved fluorescence to monitor bioactive compounds in plant based foodstuffs

The study of compounds that exhibit antioxidant activity has recently received much interest in the food industry because of their potential health benefits. Most of these compounds are plant based, such as polyphenolics and carotenoids, and there is a need to monitor them from the field through processing and into the body. Ideally, a monitoring technique should be non-invasive with the potential for remote capabilities. The application of the phenomenon of fluorescence has proved to be well suited, as many plant associated compounds exhibit fluorescence. The photophysical behaviour of fluorescent molecules is also highly dependent on their microenvironment, making them suitable probes to monitor changes in pH, viscosity and polarity, for example. Time-resolved fluorescence techniques have recently come to the fore, as they offer the ability to obtain more information, coupled with the fact that the fluorescence lifetime is an absolute measure, while steady state just provides relative and average information. In this work, we will present illustrative time-resolved measurements, rather than a comprehensive review, to show the potential of time-resolved fluorescence applied to the study of bioactive substances. The aim is to help assess if any changes occur in their form, going from extraction via storage and cooking to the interaction with serum albumin, a principal blood transport protein

Advances in non-destructive early assessment of fruit ripeness towards defining optimal time of harvest and yield prediction—a review

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Global food security for the increasing world population not only requires increased sustainable production of food but a significant reduction in pre-and post-harvest waste. The timing of when a fruit is harvested is critical for reducing waste along the supply chain and increasing fruit quality for consumers. The early in-field assessment of fruit ripeness and prediction of the harvest date and yield by non-destructive technologies have the potential to revolutionize farming practices and enable the consumer to eat the tastiest and freshest fruit possible. A variety of non-destructive techniques have been applied to estimate the ripeness or maturity but not all of them are applicable for in situ (field or glasshousassessment. This review focuses on the non-destructive methods which are promising for, or have already been applied to, the pre-harvest in-field measurements including colorimetry, visible imaging, spectroscopy and spectroscopic imaging. Machine learning and regression models used in assessing ripeness are also discussed

Automated Mobile System for Accurate Outdoor Tree Crop Enumeration Using an Uncalibrated Camera.

This paper demonstrates an automated computer vision system for outdoor tree crop enumeration in a seedling nursery. The complete system incorporates both hardware components (including an embedded microcontroller, an odometry encoder, and an uncalibrated digital color camera) and software algorithms (including microcontroller algorithms and the proposed algorithm for tree crop enumeration) required to obtain robust performance in a natural outdoor environment. The enumeration system uses a three-step image analysis process based upon: (1) an orthographic plant projection method integrating a perspective transform with automatic parameter estimation; (2) a plant counting method based on projection histograms; and (3) a double-counting avoidance method based on a homography transform. Experimental results demonstrate the ability to count large numbers of plants automatically with no human effort. Results show that, for tree seedlings having a height up to 40 cm and a within-row tree spacing of approximately 10 cm, the algorithms successfully estimated the number of plants with an average accuracy of 95.2% for trees within a single image and 98% for counting of the whole plant population in a large sequence of images

Measuring food quality: concepts, methods and challenges - Proceedings seminar February 2007

From 12 to 14 February, the Louis Bolk Instituut organised the 3rd annual QLIF workshop, titled “Measuring food quality, concepts, methods and challenges”. During these days a diverse and intensive program was presented. Participants came from, Belgium, Bulgaria, Germany, Greece, Hungary, Macedonia, Poland, Turkey. Participants were all very enthusiastic, both on the quality of the presentations and the total program. For all those of you who missed it, I give a brief impression. On the first day definitions of food quality were discussed as well as the methods to measure this quality. Machteld Huber explained the inner quality concept, developed by the Louis Bolk Instituut. This inner quality concept is based on two main life processes in organisms; Growth and Differentiation and the balance or integration of these two processes. This in contrast to many other quality definitions based on the presence or absence of substances. Analytical methods for measuring food quality (measuring substances) and experimental methods (e.g. crystallisation, biofotons ) measuring life processes were discussed. After the theoretical part, participants had the opportunity to work with biocrystallisation pictures and to visit the crystallisation laboratory. The second day started with a visit to one of the largest organic greenhouses in the Netherlands. The farmer grows tomatoes and paprika on a contract basis. Recently he started with a speciality in tomatoes, the Wild Wonders, a mixture of different shaped and coloured tomatoes. The greenhouse therefore gave a good view on the combination of ‘volume’ production and quality growing. In the afternoon, Jacob Holm Nielsen gave us a very interesting insight into the QLIF studies on organic and low input dairy. The type of feed showed to be very important for the milk composition and he emphasized that for organic high-quality dairy, maize can better be avoided as part of the feeding regime. Joke Bloksma presented the studies performed on lettuce, apple and carrot quality and how management factors (for apple, the bearing of the tree, sun light, ripening etc) influenced the quality of the products. Finally Gabriele Wyss from FIBL gave a presentation on food safety and food risks in organic production. She explained that many food safety aspects and food risks in organic are covered by conventional safety regulations and additional rules for organic farming. Because of the precautionary principles in organic food production the product safety and process safety tends to be higher in organic than in conventional. At the end of the day 4 participants presented their own research. This gave a broad view on different studies in the field of food quality and it gave rise to many questions and suggestions from other participants. The 3rd day taste and health were the main topics. Organic food might have a better taste than conventional, but how do we measure taste. Bob Cramwinckel of the Centre for Taste Research explained their 3-steps method to measure physical, psychological and total taste. Last presentation was given by Ruth Adriaansen on how we can study health effects of organic food. The necessity of a clear working definition of health showed to be very important for the design of a study, the choice of parameters and the effects to be studied. As an example, the study design of “Organic, more healthy ??”, the large feeding study in chicken, currently being performed by the Louis Bolk Instituut, was discussed. According to one of the scientific contributors the program “gave a great insight in the discussion going on in the field of organic food quality”. The overall conclusion was that for the evaluation of food quality you have to take much more aspects into account than nutritional content and contaminants only. An enlarged or holistic quality concept is needed to cover the ambitions of organic food production. Challenge is to further develop such concepts and to design robust scientific studies which account for all relevant quality aspects

Spatial development of transport structures in apple (Malus x domestica Borkh.) fruit

The void network and vascular system are important pathways for the transport of gases, water and solutes in apple fruit (Malus x domestica Borkh). Here we used X-ray micro-tomography at various spatial resolutions to investigate the growth of these transport structures in 3D during fruit development of ‘Jonagold’ apple. The size of the void space and porosity in the cortex tissue increased considerably. In the core tissue, the porosity was consistently lower, and seemed to decrease towards the end of the maturation period. The voids in the core were more narrow and fragmented than the voids in the cortex. Both the void network in the core and in the cortex changed significantly in terms of void morphology. An automated segmentation protocol underestimated the total vasculature length by 9 to 12% in comparison to manually processed images. Vascular networks increased in length from a total of 5 meter at 9 weeks after full bloom, to more than 20 meter corresponding to 5 cm of vascular tissue per cubic centimeter of apple tissue. A high degree of branching in both the void network and vascular system and a complex three-dimensional pattern was observed across the whole fruit. The 3D visualisations of the transport structures may be useful for numerical modeling of organ growth and transport processes in fruit

Measuring food quality: concepts, methods and challenges

From 12 to 14 February, the Louis Bolk Instituut organised the 3rd annual QLIF workshop, titled "Measuring food quality, concepts, methods and challenges”. During these days a diverse and intensive program was presented. Participants came from, Belgium, Bulgaria, Germany, Greece, Hungary, Macedonia, Poland, Turkey. Participants were all very enthusiastic, both on the quality of the presentations and the total program. For all those of you who missed it, I give a brief impression. On the first day definitions of food quality were discussed as well as the methods to measure this quality. Machteld Huber explained the inner quality concept, developed by the Louis Bolk Instituut. This inner quality concept is based on two main life processes in organisms; Growth and Differentiation and the balance or integration of these two processes. This in contrast to many other quality definitions based on the presence or absence of substances. Analytical methods for measuring food quality (measuring substances) and experimental methods (e.g. crystallisation, biofotons ) measuring life processes were discussed. After the theoretical part, participants had the opportunity to work with biocrystallisation pictures and to visit the crystallisation laboratory. The second day started with a visit to one of the largest organic greenhouses in the Netherlands. The farmer grows tomatoes and paprika on a contract basis. Recently he started with a speciality in tomatoes, the Wild Wonders, a mixture of different shaped and coloured tomatoes. The greenhouse therefore gave a good view on the combination of ‘volume’ production and quality growing. In the afternoon, Jacob Holm Nielsen gave us a very interesting insight into the QLIF studies on organic and low input dairy. The type of feed showed to be very important for the milk composition and he emphasized that for organic high-quality dairy, maize can better be avoided as part of the feeding regime. Joke Bloksma presented the studies performed on lettuce, apple and carrot quality and how management factors (for apple, the bearing of the tree, sun light, ripening etc) influenced the quality of the products. Finally Gabriele Wyss from FIBL gave a presentation on food safety and food risks in organic production. She explained that many food safety aspects and food risks in organic are covered by conventional safety regulations and additional rules for organic farming. Because of the precautionary principles in organic food production the product safety and process safety tends to be higher in organic than in conventional. At the end of the day 4 participants presented their own research. This gave a broad view on different studies in the field of food quality and it gave rise to many questions and suggestions from other participants. The 3rd day taste and health were the main topics. Organic food might have a better taste than conventional, but how do we measure taste. Bob Cramwinckel of the Centre for Taste Research explained their 3-steps method to measure physical, psychological and total taste. Last presentation was given by Ruth Adriaansen on how we can study health effects of organic food. The necessity of a clear working definition of health showed to be very important for the design of a study, the choice of parameters and the effects to be studied. As an example, the study design of “Organic, more healthy ??”, the large feeding study in chicken, currently being performed by the Louis Bolk Instituut, was discussed. According to one of the scientific contributors the program “gave a great insight in the discussion going on in the field of organic food quality”. The overall conclusion was that for the evaluation of food quality you have to take much more aspects into account than nutritional content and contaminants only. An enlarged or holistic quality concept is needed to cover the ambitions of organic food production. Challenge is to further develop such concepts and to design robust scientific studies which account for all relevant quality aspects

Summary report on sensory-related socio-economic and sensory science literature about organic food products

Organic food’s initial attraction to the public was that it was perceived to be healthier and tastier, but scientists and policy makers have mainly stressed the benefits to the environment of organic and sustainable farming. Scientific support for marketing actions addressed to those who want to be healthier and who want to enjoy better taste, and are willing to pay more for these benefits is scarce. Past research has produced little clear evidence about the importance of sensory characteristics such as taste, smell, appearance etc in consumers’ preferences with regard to organic food. The Ecropolis project, funded by the E.U., was set up with the aim of investigating the role of the senses in consumers’ preferences regarding organic food, and leading to research into how best to satisfy those preferences. This deliverable is aimed at providing a solid basis for such research with an in-depth review of, and two reports on, the relevant scientific literature. The first report (Annex I) regards what consumers expect from organic products in terms of taste, smell, appearance, etc and how these expectations are (or are not) met; the second is about the science of the senses (Annex II). The first project tasks included creating and agreeing on a glossary of terms, deciding on search criteria (key words, etc.), setting up a bibliographical data base, preparing then circulating the above-mentioned reports, and finally preparing a summary of the reports. The report on consumers expectations highlights the suggestion that while organic food has traditionally been marketed through specialized retailers, its market share will only grow significantly if it is promoted by multiple retailers. Research literature from all over the world seems to agree in indicating that consumers’ choices are largely motivated by health, the environment, price and social status. Other considerations include ethics, the localness of the product and lifestyle choices. The literature also indicates that the organic market will expand significantly only if consumers are more willing, and able, to recognize quality, but this presents serious issues. When buying the product they cannot personally verify its quality and genuineness and thus must rely on regulation and inspection bodies. The recognition of quality can also be encouraged by effective communication by producers and retailers through appropriate branding, labelling and presentation. There are connections between this information and questions of sense perception, but researchers disagree about how important the latter is in influencing the customer, and in which ways it does so. The following report focuses, in fact, on the science of the senses, which tries to analyze in detail people’s responses to food, despite the many potential pitfalls in carrying out the research which might influence the reliability of the results. There is broad agreement on two points: - there is no proof that organic food is more nutritious or safer, and - most studies that have compared the taste and organoleptic quality of organic andconventional foods report no consistent or significant differences between organic and conventional produce. Therefore, claiming that all organic food tastes different from all conventional food would not be correct. However, among the well-designed studies with respect to fruits and vegetables that have found differences, the vast majority favour organic produce. Organic produce tends to store better and has longer shelf life, probably because of lower levels of nitrates and higher average levels of antioxidants. The former can accelerate food spoilage, while antioxidants help preserve the integrity of cells and some are natural antibiotics. The first conclusion may, however, depend on factors not directly connected to organic farming, such as harvesting and storage methods and the type of land used for growing the food. About the second finding it must be considered that measuring organoleptic quality is difficult and inherently subjective and evaluations may be clouded by the influence of numerous factors on the consumer’s perceptions of the food and not just its appearance and taste. Experimental research indicates that the information that a food is organic confers upon it a “halo effect” (making it seem better sense-wise simply because it is organic) which might make consumers like it more. Ecropolis researchers will analyze in detail which senses are indeed impacted on, and how, and try to match them to consumer needs and expectations in order to be able to offer suggestions for future policy, including how the food is stored, transported and presented, which is also essential for maintaining sensory properties. The workpackage WP1 has also produced a specific report on how organic food sensory aspects are regulated. International standards, with some important exceptions, are largely in line with European ones. Differences in standards usually regard whether there is orientation towards freshness “per se” as opposed to increasing shelf-life, or quality standardization as opposed to quality differentiation. Differences in regulations regard such aspects as ingredients, additives, processing aids and methods, packaging, storage and transport. The lack of harmony among the different regulatory systems often reflects different traditions and market conditions, however, more complicated compliance procedures result in higher costs for importers. Greater homogeneity would not only reduce such costs but would also increase consumer confidence in international standards. Ecropolis will also investigate the effect of different regulations on how people perceive organic goods sense-wise. The work done to date is seen as a starting point for future research aimed at producing practical results in the organic food market. Ecropolis will try to bring together separate strands of research concerning how organic goods are regulated and marketed with regard to taste, appearance, etc., and how consumers themselves are affected by such factors. The aim is to find optimal matches between the two, and thus to greatly increase organic food’s share of the food market

Morphological variation on tomato leaves due to different nitrogen contents

Elliptic Fourier Analysis (EFA) is a method used to quantify shape differences.  It mathematically describes the entire shape of an object by transforming the contour into Fourier coefficients, used as variables for statistical analysis, and involving the fitting of some type of curve to the object outline.  Generally, the shape of agricultural products such as fruit, vegetables, grain and in addition other organs of plant is one of the most important factors for their classification and grading in relation to commercial quality and organoleptic properties.  The aim of this study is to quantify the morphological variation of the shape of tomato leaves in response to their different nitrogen (N) content using the EFA coefficients, the fractal geometry and the perimeter ratio in combination with the Partial Least Squares Discriminant Analysis (PLS-DA).  The analyses were realized on a tomato crop where each sample was chemically analyzed at the laboratory to establish the N content.  The leaves (168) were divided into 3 groups following different N concentrations.  Results suggest no relation between leaves lengths and N concentration is present following the Kruskal-Wallis performed with a p=0.735.  The PLS-DA performing on the EFA coefficients, fractal index and perimeter ratio shows a high sensitivity, sensibility, and reduced mean classification error (82.3%, 81.07% and 18.3% respectively).  The percentages of the correct classification in the model resulted to be 69.29% while the independent test equal to 56.1%.  This study demonstrated the relation between leaf shape and N content (expressed in 3 concentration groups).Keywords: Tomato leaf, elliptic Fourier analysis, fractal index, perimeter ratio, partial least squares discriminant analysis