Green bean biofortification for Si through soilless cultivation: Plant response and Si bioaccessibility in pods

Food plants biofortification for micronutrients is a tool for the nutritional value improvement of food. Soilless cultivation systems, with the optimal control of plant nutrition, represent a potential effective technique to increase the beneficial element content in plant tissues. Silicon (Si), which proper intake is recently recommended for its beneficial effects on bone health, presents good absorption in intestinal tract from green bean, a high-value vegetable crop. In this study we aimed to obtain Si biofortified green bean pods by using a Si-enriched nutrient solution in soilless system conditions, and to assess the influence of boiling and steaming cooking methods on Si content, color parameters and Si bioaccessibility (by using an in vitro digestion process) of pods. The Si concentration of pods was almost tripled as a result of the biofortification process, while the overall crop performance was not negatively influenced. The Si content of biofortified pods was higher than unbiofortified also after cooking, despite the cooking method used. Silicon bioaccessibility in cooked pods was more than tripled as a result of biofortification, while the process did not affect the visual quality of the product. Our results demonstrated that soilless cultivation can be successfully used for green bean Si biofortification

Supplementary Far-Red Light Did Not Affect Tomato Plant Growth or Yield under Mediterranean Greenhouse Conditions

In the Mediterranean region, tomato plants are often cultivated in two short cycles per year to avoid the heat of summer and the low solar radiation of winter. Supplementary light (SL) makes it possible to cultivate during the dark season. In this experiment, a tomato F1 hybrid cultivar DRW7723 was cultivated in a greenhouse for a fall-winter cycle. After transplant, light emitting diode (LED) interlighting, with two light spectra (red + blue vs. red + blue + far-red) was applied as SL. Plant growth, yield, gas exchange, nutrient solution (NS) consumption, and fruit quality were analyzed. In general, the eects of adding far-red radiation were not visible on the parameters analyzed, although the yield was 27% higher in plants grown with SL than those grown without. Tomatoes had the same average fresh weight between SL treatments, but the plants grown with SL produced 16% more fruits than control. Fruit quality, gas exchange and NS uptake were not influenced by the addition of far-red light. Interlighting is, therefore, a valid technique to increase fruit production in winter but at our latitude the eects of adding far-red radiation are mitigated by available sunlight

Mineral Composition and Bioaccessibility in Rocket and Purslane after Zn Biofortification Process

Zinc (Zn) is an essential key nutrient in different biochemical and physiological processes. The nutritional deficit of this mineral element is estimated to affect the health of over 3 billion people worldwide. Several strategies are available to reduce the negative impact of mineral malnutrition; among them, biofortification is the practice of deliberately increasing the nutrients and healthy compounds in the edible parts of vegetables. This study aims to evaluate Zn bioaccessibility in biofortified and non-biofortified rocket and purslane using an in vitro gastrointestinal digestion process and measure the concentration of other mineral elements (Al, B, Ca, Fe, K, Mg, Mn, and Sr) released during the digestion process from rocket and purslane biofortified with Zn. The bioaccessible Zn in biofortified rocket and purslane ranged from 7.43 to 16.91 mg/kg, respectively. In addition, the daily intake, the RDA coverage (%), and the hazard quotient (HQ) for the intake of Zn (resulting from the consumption of 100 g of rocket and purslane) were calculated. The calculated HQ highlights the safety of these baby leaf vegetables. The study confirms that it is possible to obtain Zn-biofortified rocket and purslane with high Zn bioaccessibility by adopting an appropriate mineral plant nutrition solution enriched in Zn

Reduced Fertilization to Improve Sustainable Use of Resources and Preserve Postharvest Quality of Fresh-Cut Wild Rocket (<i>Diplotaxis tenuifolia</i> L.) in Soil-Bound and Soilless Cultivation

Reducing fertilizer input is a goal for helping greenhouse farming to achieve higher sustainability in the production process while preserving overall crop performance and quality. Wild rocket plants were cultivated in a plastic greenhouse divided into two independent sectors, one for soil-bound (SbS) cultivation and another equipped for soilless (ScS) cultivation systems. In both SbS and ScS, the crop was subjected to treatments consisting of a high- and a low-input fertilization program (HF and LF treatment, respectively). Water use efficiency (WUE) and partial factor productivity (PFP) for nutrients (N, P, K, Ca, and Mg for ScS, and N for SbS) were measured. Rocket leaves, separated for the cultivation system and fertilization program and collected at different cuts during the growing cycle, were cold stored at 10 °C until 16 d. On each sampling day (at harvest and during storage), the sensory parameters, respiration rate, dry matter, color, electrolyte leakage, antioxidant activity, total phenols, total chlorophyll and ammonia content were evaluated. In ScS, the PFP for all nutrients supplied as fertilizers showed a significant increase with the LF treatment, with values higher than 30% recorded for N, K, and Ca. As for the postharvest performance, rocket leaves cultivated in ScS showed better qualitative traits than those cultivated in SbS, as suggested by the lower values of ammonia content and electrolyte leakage recorded at the end of storage period in samples grown in ScS. Moreover, in ScS, the data showed lower membrane damage in LF than HF rocket leaves. Finally, regarding total chlorophyll content, even if no effect of each treatment was recorded in SbS, rocket cultivated in ScS showed a better retention of this parameter by applying LF rather than HF treatment. In addition to this, a PLS model (R2 = 0.7) able to predict the cultivation system, using as a variable non-destructively measured total chlorophyll content, was implemented. Low fertilization input, both in SbS and in ScS, allowed satisfying production levels and more sustainable management of nutrients. LF treatment applied to ScS also had in positive effects on the postharvest quality of fresh-cut rocket leaves

Minimizing water and nutrient losses from soilless cropping in southern Europe

In agriculture, soilless cropping represents the most suitable cultivation technique apt to achieve a theoretical 100 % efficiency of water and nutrient use. This is possible through a high control of input streams in the cultivation system. Soilless cultivation indeed allows high precision in nutrient and water management so that particular agronomic techniques, which are risky in other cultivation systems (e.g., nutrient depletion or the maintenance of low nutrient concentrations in the root zone), can be managed more safely under soilless conditions. Even in the so-called open (free-drain) cycles, water and nutrient losses can be minimized by the combination of sensing technologies and nutrient delivery strategies aiming at “zero emissions”. However, soilless cropping allows collection and reuse of the drainage in closed growing systems, thereby avoiding or minimizing water and nutrient losses into the environment. The main challenge when managing closed systems in southern Europe conditions is usually the progressive salinization of the recirculating solution because of saline irrigation waters often available in many in coastal areas of the Mediterranean. The use of alternative water sources like rainwater or desalinated water can prevent this problem, but their availability is limited. Advanced recirculation strategies have demonstrated a high potential for reusing the solution under saline conditions with optimal use and minimal discharge of nutrients. Hence, there is currently enough knowledge to support a larger application of closed soilless systems in Mediterranean conditions. On the other hand, proper choices in terms of cultivation facilities and structures and plant material can be relevant to achieve high water and nutrient use efficiency. The main relevant techniques (e.g., nutrient solution management strategies, and right choice of planting material) and technologies (e.g., sensing technologies and greenhouse structures) to minimize water and nutrient losses from soilless-grown vegetable crops in southern Europe are reviewed in this paper

Cultivation of Potted Sea Fennel, an Emerging Mediterranean Halophyte, Using a Renewable Seaweed-Based Material as a Peat Substitute

Sea fennel (Crithmum maritimum L.), an emerging halophyte species, represents a nutritious and refined food product. In this study, the effect on yield and quality of potted sea fennel grown on three posidonia (Podisonia oceanica (L.) Delile)-based composts (a municipal organic solid waste compost, a sewage sludge compost and a green compost) and a peat-based substrate was analyzed. Composts were used both pure and mixed with peat at a dose of 50% on a volume basis. We hypothesized that the halophytic nature of this plant might overcome the limitations of high-salinity compost-based growing media. The growth parameters, color traits and trace metals content (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of the edible parts were compared. Independently of the substrates, the average total and edible yields were 51 and 30 g plant&minus;1, respectively, while the average waste portion was about 41%. The use of posidonia-based compost did not affect the color traits of sea fennel plants as compared with samples grown on the commercial peat-based substrate. In general, potted sea fennel grown on both posidonia-based composts and commercial peat-based substrate appeared a good source of essential micronutrients. Only a weak reduction of Fe and Mn concentrations was observed in plants grown on posidonia-based composts, especially when used at the highest dose. Independently of the growing medium, the content of potentially hazardous trace elements (Cd and Pb) in the edible parts of sea fennel was always below the maximum admissible limits fixed by the European legislation. Results indicate that posidonia-based composts can be used as a sustainable peat substitute for the formulation of soilless mixtures to grow potted sea fennel plants, even up to a complete peat replacement

Soilless cultivation systems to produce tailored microgreens for specific nutritional needs

BACKGROUNDThe awareness of the importance of following dietary recommendations that meet specific biological requirements related to an individual's health status has significantly increased interest in personalized nutrition. The aim of this research was to test agronomic protocols based on soilless cultivation for providing consumers with new dietary sources of iodine (I), as well as alternative vegetable products to limit dietary potassium (K) intake; proposed cultivation techniques were evaluated according to their suitability to obtain such products without compromising agronomic performance.RESULTSTwo independent experiments, focused on I and K respectively, were conducted in a commercial greenhouse specializing in soilless production. Four different species were cultivated using three distinct concentrations of I (0, 1.5 and 3 mg L-1) and K (0, 60 and 120 mg L-1). Microgreens grown in I-rich nutrient solution accumulate more I, and the increase is dose-dependent. Compared to unbiofortified microgreens, the treatments with 1.5 and 3 mg L-1 of I resulted in 4.5 and 14 times higher I levels, respectively. Swiss chard has the highest levels of K (14 096 mg kg-1 of FW), followed by rocket, pea and radish. In radish, rocket and Swiss chard, a total reduction of K content in the nutrient solution (0 mg L-1) resulted in an average reduction of 45% in K content.CONCLUSIONIt is possible to produce I-biofortified microgreens to address I deficiency, and K-reduced microgreens for chronic kidney disease-affected people. Species selection is crucial to customize nutritional profiles according to specific dietary requirements due to substantial mineral content variations across different species. (c) 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry

NaCl stress enhances silicon tissue enrichment of hydroponic â\u80\u9cbaby leafâ\u80\u9d chicory under biofortification process

The effects of saline stress on the silicon (Si) tissue enrichment (Si biofortification) of ready-to-eat â\u80\u9cbaby leafâ\u80\u9d chicory in hydroponic floating system were studied. Four combinations of Si and NaCl levels in the nutrient solution were compared: i) 0 mM Si - 0 mM NaCl (â\u80\u98Controlâ\u80\u99); ii) 3.6 Si - 0 NaCl (â\u80\u98Siâ\u80\u99); iii) 0 Si - 50 NaCl (â\u80\u98NaClâ\u80\u99); and iv) 3.6 Si - 50 NaCl (â\u80\u98Si + NaClâ\u80\u99). Si in combination with salt stress enhanced the Si tissue enrichment with respect to biofortification under control conditions [11.4 vs 3.06 mg 100 gâ\u88\u921fresh weight (FW), respectively]. However, Si was not able to restore growth of plants under salinity compared to normal conditions. Bioaccessible Si in chicory under â\u80\u98Si + NaClâ\u80\u99 treatment was the highest in the experiment (3.73 mg 100 gâ\u88\u921FW). The nitrate content was not influenced by salinity neither by Si, while the oxalate content was extremely low in all treatments, thus not compromising the enhanced nutritional value of the biofortified chicory. Application of salt stress could be considered an effective strategy to enhance the silicon tissue enrichment of hydroponic chicory under biofortification process

Self-Configuring CVS to Discriminate Rocket Leaves According to Cultivation Practices and to Correctly Attribute Visual Quality Level

Computer Vision Systems (CVS) represent a contactless and non-destructive tool to evaluate and monitor the quality of fruits and vegetables. This research paper proposes an innovative CVS, using a Random Forest model to automatically select the relevant features for classification, thereby avoiding their choice through a cumbersome and error-prone work of human designers. Moreover, three color correction techniques were evaluated and compared, in terms of classification performance to identify the best solution to provide consistent color measurements. The proposed CVS was applied to fresh-cut rocket, produced under greenhouse soilless cultivation conditions differing for the irrigation management strategy and the fertilization level. The first aim of this study was to objectively estimate the quality levels (QL) occurring during storage. The second aim was to non-destructively, and in a contactless manner, identify the cultivation approach using the digital images of the obtained product. The proposed CVS achieved an accuracy of about 95% in QL assessment and about 65–70% in the discrimination of the cultivation approach

Sensor-Based Fertigation Management Enhances Resource Utilization and Crop Performance in Soilless Strawberry Cultivation

The use of wireless sensors for real-time sensing of substrate water status and electrical conductivity could be an effective tool for precision irrigation management in soilless cultivation. In this research, the effects of timer-based (TB) compared to smart sensor-based irrigation (SB) were investigated. The highest consumption of fertilizers and water were recorded in TB, with nutrient solution and total applied water savings of 38% and 26%, respectively, in SB. The highest yield was obtained in SB treatment, with a total and marketable yield decrease of 7% in TB, with no differences in terms of the total soluble solids content, dry matter, firmness, juice pH and titratable acidity of the strawberry fruits. The higher yield, combined with water and nutrient saving in SB, allowed water use efficiency (fresh weight of marketable fruits per liter of total water applied) to be increased by 46% and nutrient productivity (fresh weight of marketable product per gram of nutrient supplied via nutrient solution) by 74%. The study confirms that sensor-based, compared to empiric fertigation management, ameliorates the sustainability of open, free-drain, soilless cultivation of strawberry, leading to better resource use without compromising crop performance and fruit quality