Leafy Crops Research Articles

Pharmaceutical and personal care products in recycled water for edible crop irrigation: Understanding the occurrence, crop uptake, and water quantity effects

Global water scarcity poses a great challenge to agriculture productivity. Recycled water offers a promising alternative for agricultural irrigation, yet residual pharmaceutical and personal care products (PPCPs) in recycled water can transfer to edible crops during irrigation, and adversely affect food safety. Furthermore, irrigation water quantity can influence the accumulation of PPCPs in edible crops. This study comprehensively investigates the use of recycled water for agricultural irrigation by critically reviewing three key components: PPCPs occurrence in recycled water, their accumulation in edible crops, and the impact of water quantity on PPCPs accumulation. Literature analysis showed that PPCPs were present from 130 to 1400 ng/L in secondary effluent and 25–400 ng/L in tertiary effluent, with sulfamethoxazole being the most prevalent in both effluents. PPCPs uptake and accumulation varied between leafy and fruity vegetables, with diclofenac accumulating highest in leafy vegetables and fluoxetine in fruity vegetables. Furthermore, the water requirement of leafy and fruity crops vary throughout the growing season. In leafy vegetables, PPCPs accumulation in leaves is influenced by transpiration rate, with reduced accumulation occurring under limited water availability due to slower transpiration. In fruity vegetables, osmotic adjustment drives the water transport in fruits, leading to increased PPCPs accumulation under limited water conditions. This study contributes insights into PPCPs occurrence, accumulation, and irrigation water quantity, aiding in the development of effective strategies for recycled water use in agriculture.

A study of genetic diversity of Brassica rapa L. accessions from the VIR collection by analyzing DNA polymorphism in microsatellite loci

The species Brassica rapa L. includes leafy and root crops grown in many countries of the world. Clarification of genetic relationships and population structure allows for a more accurate parental line selection for further breeding using genetically distinct forms. The B. rapa collection maintained at VIR contains 1750 accessions representing different subspecies and countries of origin, and it is a good tool for studying the diversity of cultivated forms using molecular genetic methods. The aim of the study was to investigate the genetic diversity and clarify the relationships within the B. rapa species using molecular markers. Molecular screening of 80 accessions using 16 microsatellite markers revealed alleles ranging in size from 85 to 460 bp with an average of 7.8 alleles per locus. The average polymorphic index content (PIC) was 0.278, and the expected heterozygosity (H) averaged was 0.35. Rare and unique alleles were identified for Beijing cabbage (k-63 and k-108), Japanese leafy vegetables (k-217 and k-335) and turnip (k-738) samples. Alleles of SSR loci BRMS-007 (123 bp) and BRMS-034 (136 bp) were identified, which are characteristic only of accessions of turnips, rapeseed and sarsons. In silico analysis of primer pairs was performed to clarify the sizes of expected fragments relative to the reference genome CAAS_Brap_v3.01 of Chinese cabbage line Chiifu-401-42. Phylogenetic analysis was performed using the STRUCTURE program and resulted in the distribution of accessions into four clusters according to botanical classification: Chinese cabbage; pakchoi, tatsoi; Japanese leafy vegetables, wutacai, tsoisum, mizuna and mibuna (kyona) and hybrid forms; turnip and rape accessions.

Characterization of a new dwarf watercress (Nasturtium officinale R Br.) ‘Boldrewood’ in commercial trials reveals a consistent increase in chemopreventive properties in a longer-grown crop

We describe ‘Boldrewood’, a new accession of watercress (Nasturtium officinale R. Br.) that was initially found to be of short stature with high antioxidant capacity (Payne et al. 2015). This was of particular commercial interest because it offered the potential to develop a novel watercress product with fork-friendly size and improved health-benefits. In two commercial trials comparing Boldrewood to a control, we confirmed that Boldrewood exhibits a dwarf phenotype with a significantly shorter stem and consistently produced more leaves per stem area alongside comparable crop biomass. The antioxidant and chemopreventive capacity of Boldrewood were comparable to the commercial crop. For the first time, we observed a novel increase in glucosinolate concentrations and cytotoxicity to cancer cells, characterised as decreased IC50 (half-maximal concentration of an inhibitor), associated with increased crop age at harvest. This suggests that a slower-growing and longer to harvest crop provides a significant improvement in health benefits gained in this leafy crop which is already known to be highly nutrient dense and with considerable chemopreventive ability.

Spinach genomes reveal migration history and candidate genes for important crop traits.

Spinach (Spinacia oleracea) is an important leafy crop possessing notable economic value and health benefits. Current genomic resources include reference genomes and genome-wide association studies. However, the worldwide genetic relationships and the migration history of the crop remained uncertain, and genome-wide association studies have produced extensive gene lists related to agronomic traits. Here, we re-analysed the sequenced genomes of 305 cultivated and wild spinach accessions to unveil the phylogeny and history of cultivated spinach and to explore genetic variation in relation to phenotypes. In contrast to previous studies, we employed machine learning methods (based on Extreme Gradient Boosting, XGBoost) to detect variants that are collectively associated with agronomic traits. Variant-based cluster analyses revealed three primary spinach groups in the Middle East, Asiaand Europe/US. Combining admixture analysis and allele-sharing statistics, migration routes of spinach from the Middle East to Europe and Asia are presented. Using XGBoost machine learning models we predict genomic variants influencing bolting time, flowering time, petiole color, and leaf surface texture and propose candidate genes for each trait. This study enhances our understanding of the history and phylogeny of domesticated spinach and provides valuable information on candidate genes for future genetic improvement of the crop.

Foliar selenium biofortification of soybean: the potential for transformation of mineral selenium into organic forms.

Selenium (Se) deficiency, stemming from malnutrition in humans and animals, has the potential to disrupt many vital physiological processes, particularly those reliant on specific selenoproteins. Agronomic biofortification of crops through the application of Se-containing sprays provides an efficient method to enhance the Se content in the harvested biomass. An optimal candidate for systematic enrichment, guaranteeing a broad trophic impact, must meet several criteria: (i) efficient accumulation of Se without compromising crop yield, (ii) effective conversion of mineral Se fertilizer into usable organically bound Se forms (Seorg), (iii) acceptance of a Se-enriched crop as livestock feed, and (iv), interest from the food processing industry in utilization of Se-enriched outputs. Hence, priority should be given to high-protein leafy crops, such as soybean. A three-year study in the Czech Republic was conducted to investigate the response of field-grown soybean plants to foliar application of Na2SeO4 solutions (0, 15, 40, and 100 g/ha Se); measured outcomes included crop yield, Se distribution in aboveground biomass, and the chemical speciation of Se in seeds. Seed yield was unaffected by applied SeO4 2-, with Se content reaching levels as high as 16.2 mg/kg. The relationship between SeO4 2-dose and Se content in seeds followed a linear regression model. Notably, the soybeans demonstrated an impressive 73% average recovery of Se in seeds. Selenomethionine was identified as the predominant species of Se in enzymatic hydrolysates of soybean, constituting up to 95% of Seorg in seeds. Minor Se species, such as selenocystine, selenite, and selenate, were also detected. The timing of Se spraying influenced both plant SeO4 2- biotransformation and total content in seeds, emphasizing the critical importance of optimizing the biofortification protocol. Future research should explore the economic viability, long-term ecological sustainability, and the broad nutritional implications of incorporating Se-enriched soybeans into food for humans and animals.

Statement on the toxicological properties and maximum residue levels of acetamiprid and its metabolites.

Acetamiprid is a pesticide active substance with insecticidal action whose approval was renewed by Commission Implementing Regulation (EU) 2018/113. In January 2022, the EFSA PPR Panel published a statement following a request from the European Commission to advise on human health or the environment based on new scientific evidence presented by France during the decision-making phase. In July 2022, by means of a further mandate received from the European Commission, EFSA was requested to provide advice if new information and any other scientific evidence that has become available since the assessment conducted for the renewal in 2018 warrant re-evaluation of (i) toxicological parameters used for the risk assessment of acetamiprid during the renewal process, including toxicological endpoints; (ii) the residue definition for acetamiprid in products of plant origin; and (iii) the safety of existing maximum residue levels (MRLs). Meanwhile, the applicant of acetamiprid in the EU submitted new toxicology studies regarding the toxicological profile of the metabolite IM-2-1. Furthermore, the European Commission was made aware that several recent publications in scientific literature were made available after the literature searches conducted by EFSA. As the new data could affect the advice that EFSA was expected to deliver through the 2022 mandate, EFSA was further requested to consider this information by means of a revised mandate received in September 2023. As regards re-evaluation of point (i) in this statement, this was addressed by an EFSA Working Group integrating all the available evidence. The results of the weight of evidence indicated that there are major uncertainties in the body of evidence for the developmental neurotoxicity (DNT) properties of acetamiprid and further data are therefore needed to come to a more robust mechanistic understanding to enable appropriate hazard and risk assessment. In view of these uncertainties, the EFSA WG proposed to lower the acceptable daily intake (ADI) and acute reference dose (ARfD) from 0.025 to 0.005 mg/kg body weight (per day). A revised residue definition for risk assessment was proposed for leafy and fruit crops as sum of acetamiprid and N-desmethyl-acetamiprid (IM-2-1), expressed as acetamiprid. Regarding pulses/oilseeds, root crops and cereals, the new data received did not indicate a need to modify the existing residue definition for risk assessment, which therefore remains as parent acetamiprid. Regarding the residue definition for enforcement, the available data did not indicate a need to modify the existing definition because acetamiprid is still a sufficient marker of the residues in all crop groups. Considering the new health-based guidance values derived in the present statement, a risk for consumer has been identified for 38 MRLs currently in place in the EU Regulation. Consequently, EFSA recommended to lower the existing MRLs for 38 commodities based on the assessment of fall-back Good Agricultural Practices received within an ad hoc data call. Some fall-back MRLs proposals require further risk management considerations.

INFLUENCE OF BORDEAUX MIXTURE AND CLYBIO ON GROWTH AND YIELD OF INDIAN SPINACH (Basella alba L.)

The experiment was conducted at the Horticultural Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, during the period of May to July 2023. The single factor experiment was laid out in Completely Randomized Design (CRD) with three replications to determine the growth and yield of Indian Spinach (Basella alba L.). The experiment consisted of three treatments, namely: T1: Control; T2: Bordeaux Mixture (three times with ten days interval) and T3: Clybio (three times with ten days interval). Significant variations were observed in all treatments when data pertaining to various growth and yield parameters were collected, where the average tallest plant (187.3 cm), maximum SPAD value (37.9), maximum leaf area (252.6 sq cm), stem diameter (21.4 mm), maximum root weight (39.4 g), highest yield per plant (484.9 g) and highest yield per ha (17.81 ton) were found in (T3: Clybio) application, while the shortest plant (42.8 cm), minimum SPAD value (30.3), minimum leaf area (112.1 sq cm), lowest yield per plant (420.5 g), and lowest yield per ha (15.6 tons) were found in Bordeaux Mixture (T2). On the basis of the whole experiment, it can be concluded that Clybio as a bio-fertilizer, possesses the inherent potential to enhance the growth and yield of Indian spinach, thereby indicating its capacity to exert a positive influence on the overall development and productivity of this leafy green crop.

The potential of young vegetative quinoa (Chenopodium quinoa) as a new sustainable protein-rich winter leafy crop under Mediterranean climate

The demand for protein products has significantly risen in the last few years. In western countries, animals are the primary source of protein; however, plants could take a share of this market due to lower production costs, among other advantages such as a lower environmental footprint. Quinoa (Chenopodium quinoa Willd.) is a well-known but under-utilized protein-rich crop, commonly cultivated for grain production. These plants were recently evaluated for their use as a non-traditional, green leafy crop. Here we assessed the potential of young vegetative quinoa as a new sustainable winter leafy crop in Israel—serving as a model for Mediterranean semi-arid regions, by evaluating yield, protein content and quality. Five quinoa accessions were sown on three winter sowing dates over two consecutive years. Plants were harvested when they reached 10% dry matter (DM). DM yield ranged between 574 and 1,982 kg ha-1 and was generally higher in the second year. Protein content ranged from 14.4–34% and was generally higher in the first year. Protein yield ranged from 111–471 kg ha-1 and was greatest on the December sowing date. DM and protein yields were positively correlated with plant density. Protein content was negatively correlated with plant density and DM yield. Our findings show that 200 g DM of young vegetative quinoa can meet the protein and most essential amino acid requirements for a 70 kg human adult. Prospects for cultivating young vegetative quinoa in Mediterranean countries as a new sustainable, protein-rich winter leafy crop are therefore high, as supported by its high protein yields and quality, and its requirement for only scant irrigation. Further studies should examine economic and other agrotechnical parameters toward the geographical distribution and expansion of young vegetative quinoa cultivation.

Agricultural practices and intestinal parasites: A study of socio-environmental risk factors associated with leafy vegetable production in La Plata horticultural area, Argentina

Foodborne diseases now represent one of the most important public health problems. The objectives were to analyze the leafy vegetables and crop soil to detect parasitic species and evaluate the factors that increase the risk of parasitic contamination in the productive units in La Plata horticultural area. The study included 261 leafy vegetable and 87 crop soil samples that were processed using washing, sedimentation, and flotation techniques. Socio-environmental characteristics and agricultural practices were surveyed, and a generalized linear model was used to assess the change in parasitic prevalence with different predictor variable. The 58.6% of leafy vegetable and 31.0% of crop soil samples contained parasitic species, the most prevalent being Blastocystis sp. and oocysts of Cryptosporidium spp. Risk factors were the limited access to health, dirt roads, children and dogs circulating in crops, field cultivation, furrow irrigation and lettuce cultivation. The high prevalence of intestinal parasites in the vegetable crops was mainly associated with the conditions of structural precariousness in the production units. These results elaborated with the participation of the population, provide valuable knowledge for the planning of epidemiological programs that include environmental health as a fundamental nexus in health campaigns.

Crop diagnostic system: A robust disease detection and management system for leafy green crops grown in an aquaponics facility

Crops grown on aquaponics farms are susceptible to various diseases or biotic stresses during their growth cycle, just like traditional agriculture. The early detection of diseases is crucial to witnessing the efficiency and progress of the aquaponics system. Aquaponics combines recirculating aquaculture and soilless hydroponics methods and promises to ensure food security, reduce water scarcity, and eliminate carbon footprint. For the large-scale implementation of this farming technique, a unified system is needed that can detect crop diseases and support researchers and farmers in identifying potential causes and treatments at early stages. This study proposes an automatic crop diagnostic system for detecting biotic stresses and managing diseases in four leafy green crops, lettuce, basil, spinach, and parsley, grown in an aquaponics facility. First, a dataset comprising 2640 images is constructed. Then, a disease detection system is developed that works in three phases. The first phase is a crop classification system that identifies the type of crop. The second phase is a disease identification system that determines the crop's health status. The final phase is a disease detection system that localizes and detects the diseased and healthy spots in leaves and categorizes the disease. The proposed approach has shown promising results with accuracy in each of the three phases, reaching 95.83%, 94.13%, and 82.13%, respectively. The final disease detection system is then integrated with an ontology model through a cloud-based application. This ontology model contains domain knowledge related to crop pathology, particularly causes and treatments of different diseases of the studied leafy green crops, which can be automatically extracted upon disease detection allowing agricultural practitioners to take precautionary measures. The proposed application finds its significance as a decision support system that can automate aquaponics facility health monitoring and assist agricultural practitioners in decision-making processes regarding crop and disease management.

Trends of pesticide residues in agricultural products in the Chinese market from 2011 to 2020

Pesticide residues in market products pose a serious threat to consumers' health. This study aimed to analyze pesticide residues in agricultural products in the Chinese market. According to the data on agricultural products exceeding maximum residue levels (MRLs) obtained by the market supervision administration, 5387 batches of agricultural products (BAPs) in the Chinese market from 2011 to 2020 were extracted. The basic information of the data, time, region, crops and pesticides were discussed. The characteristics and trends of unqualified pesticide residues (UQPRs) in the Chinese market were statistically analyzed. The results showed that the BAPs withUQPRs increased over time, mainly occurring in spring and autumn. Most of the crops with UQPRs were leafy crops, among which Leek and Celery accounted for 28.3% and 16.9% of the total, respectively. Meanwhile, the regions with the most BAPs were Shandong, Henan, and Chongqing. Combining the statistical results and analyzing the reasons, the occurrence of UQPRs can be reduced from three aspects: government, market, and farmers.

Lettuce weed control with prior soil solarization

Lettuce is a leafy crop appreciated for the supply of nutrients that favor the immune system. However, like other crops, it is subject to weed interference. Due to its low competitiveness and the impacts of herbicides, it is necessary to search new ways to control weeds. This work aims to determine the effects of solarization on weed control and on the productivity of 'Verônica' lettuce with or without soil revolving after solarization (SRAS). The experimental design was randomized blocks in a factorial scheme 7x2 with four replications. The beds were weeded, irrigated and covered with 150 µm-thick transparent polyethylene in different periods (first factor): five solarization periods (75, 60, 45, 30, and 15 days prior to planting) and two controls (without and with weeds), with or without SRAS (second factor). Weed phytosociology (frequency, density and relative dominance, importance value index, and relative importance) and lettuce productivity were evaluated. The control of the weed community (with a predominance of Java grass, Indian goosegrass, and crabgrass) with solarization is not efficient. However, the non-SRAS treatment decreases the density of some weeds and positively affects the productivity and commercial characteristics of lettuce.

Synergistic interplay between ABA-generating bacteria and biochar in the reduction of heavy metal accumulation in radish, pakchoi, and tomato

Heavy metal (HM) contamination is an environmental concern that threatens the agricultural product safety and human health. To address this concern, we developed a novel strategy involving the synergistic application of Azospirillum brasilense, a growth-promoting rhizobacterium which produces abscisic acid (ABA), and biochar to minimize HM accumulation in the edible parts of vegetable crops. Compared to A. brasilense or biochar alone, the concentrations of Cd, Ni, Pb, and Zn in radish (Raphanus sativus L.), pakchoi (Brassica chinensis L.), and tomato (Lycopersicon esculentum L.) decreased by 18–63% and 14–56%, respectively. Additionally, the synergistic treatment led to a 14–63% decrease in the bioconcentration factor. The biomass of the edible parts of the three crops increased by 65–278% after synergistic treatment, surpassing the effects of single treatments. Furthermore, the synergistic application enhanced the SPAD values by 1–45% compared to single treatments. The MDA concentrations in stressed plants decreased by 16–39% with the bacteria-biochar co-treatment compared to single treatments. Co-treatment also resulted in increased soluble protein and sugar concentrations by 8–174%, and improvements in flavonoids, total phenols, ascorbic acid, and DPPH levels by 2–50%. Pearson correlation analysis and structural equation modeling revealed that the synergistic effect was attributed to the enhanced growth of A. brasilense facilitated by biochar and the improved availability of HMs in soils. Notably, although ABA concentrations were not as high as those achieved with A. brasilense alone, they were maintained at relatively high levels. Overall, the synergistic application of A. brasilense-biochar might have remarkable potential for reducing the accumulation of HMs while promoting growth and improving nutritional and antioxidant qualities in tuberous, leafy, and fruit crops.

Vacuolar Ca2+/H+ exchanger and Ca2+-ATPase homologues are differentially regulated in tipburn-resistant and susceptible lettuce (Lactuca sativa) cultivars

Tipburn is a physiological disorder of lettuce (Lactuca sativa) and other leafy crops that causes external and internal leaf discolouration and results in serious quality issues for the fresh produce industry. Tipburn occurrence is difficult to predict and no completely effective control methods exist. This is compounded by poor knowledge of the underlying physiological and molecular basis of the condition, which appears to be associated with deficiency of calcium and other nutrients. Vacuolar calcium transporters, which are involved in calcium homeostasis in Arabidopsis, show differential expression in tipburn-resistant and susceptible Brassica oleracea lines. We therefore investigated expression of a subset of L. sativa vacuolar calcium transporter homologues, belonging to the Ca2+/H+ exchanger and Ca2+-ATPase classes, in tipburn-resistant and susceptible cultivars. This indicated that some L. sativa vacuolar calcium transporter homologues belonging to these gene classes exhibited higher expression levels in resistant cultivars, whilst others had higher expression in susceptible cultivars or were independent of tipburn phenotype. In addition, some homologues were more highly expressed in symptomatic versus asymptomatic leaves in susceptible cultivars, suggesting that tipburn-induced increases in expression are unsuccessful in conferring resistance and that differential baseline expression of such genes is important for tipburn resistance. Knowledge of individual genes associated with tipburn resistance will improve breeding for such traits and the development of resistant lettuce varieties.

Glutamate, Humic Acids and Their Combination Modulate the Phenolic Profile, Antioxidant Traits, and Enzyme-Inhibition Properties in Lettuce.

Lettuce (Lactuca sativa L., Asteraceae) is a popular vegetable leafy crop playing a relevant role in human nutrition. Nowadays, novel strategies are required to sustainably support plant growth and elicit the biosynthesis of bioactive molecules with functional roles in crops including lettuce. In this work, the polyphenolic profile of lettuce treated with glutamic acid (GA), humic acid (HA), and their combination (GA + HA) was investigated using an untargeted metabolomics phenolic profiling approach based on high-resolution mass spectrometry. Both aerial and root organ parts were considered, and a broad and diverse phenolic profile could be highlighted. The phenolic profile included flavonoids (anthocyanins, flavones, flavanols, and flavonols), phenolic acids (both hydroxycinnamics and hydroxybenzoics), low molecular weight phenolics (tyrosol equivalents), lignans and stilbenes. Overall, GA and HA treatments significantly modulated the biosynthesis of flavanols, lignans, low molecular weight phenolics, phenolic acids, and stilbene. Thereafter, antioxidant capacity was evaluated in vitro with 2,2-diphenyln-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and cupric ion reducing antioxidant capacity (CUPRAC) assays. In addition, this study examined the inhibitory properties of enzymes, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, alpha-amylase, and alpha-glucosidase. Compared to individual treatments, the combination of GA + HA showed stronger antioxidant abilities in free radical scavenging and reducing power assays in root samples. Moreover, this combination positively influenced the inhibitory effects of root samples on AChE and BChE and the tyrosinase inhibitory effect of leaf samples. Concerning Pearson's correlations, antioxidant and enzyme inhibition activities were related to phenolic compounds, and lignans in particular correlated with radical scavenging activities. Overall, the tested elicitors could offer promising insights for enhancing the functional properties of lettuce in agricultural treatments.

Hydroponic and Aquaponic Floating Raft Systems Elicit Differential Growth and Quality Responses to Consecutive Cuts of Basil Crop.

Basil crops are appreciated for their distinct flavour and appeal to various cuisines globally. Basil production is mainly implemented in controlled environment agriculture (CEA) systems. Soil-less cultivation (e.g., hydroponic) is optimal for producing basil, while aquaponics is another technique suitable for leafy crops such as basil. Shortening the production chain through efficient cultivation techniques reduces basil production's carbon footprint. While the organoleptic quality of basil demonstrably benefits from successive cuts, no studies have compared the impact of this practice under hydroponic and aquaponic CEA conditions. Hence, the present study evaluated the eco-physiological, nutritional, and productive performance of Genovese basil cv. Sanremo grown in hydroponic and aquaponic systems (combined with tilapia) and harvested consecutively. The two systems showed similar eco-physiological behaviour and photosynthetic capacity, which were on average 2.99 µmol of CO2 m-2 s-1, equal numbers of leaves, and fresh yields of on average 41.69 and 38.38 g, respectively. Aquaponics yielded greater dry biomass (+58%) and dry matter content (+37%), while the nutrient profiles varied between the systems. The number of cuts did not influence yield; however, it improved dry matter partitioning and elicited a differential nutrient uptake. Our results bear practical and scientific relevance by providing useful eco-physiological and productive feedback on basil CEA cultivation. Aquaponics is a promising technique that reduces chemical fertiliser input and increases the overall sustainability of basil production.

The impact of wounding and postharvest storage conditions on retention of soluble protein in sugar beet leaves.

Sugar beet leaves can be a viable and economically interesting source of high-quality protein for the food industry. We investigated how storage conditions and leaf wounding at harvest affect the content and quality of the soluble protein. After collection, leaves were either stored intact or shredded to mimic wounding induced by commercial leaf harvesters. Leaf material was stored in small volumes at different temperatures to assess leaf physiology or in larger volumes to assess temperature development at different locations in the bins. Protein degradation was more pronounced at higher storage temperatures. Wounding accelerated the degradation of soluble protein at all temperatures. Both wounding and storage at higher temperatures greatly stimulated respiration activity and heat production. At temperatures below 5°C, ribulose-1,5-biphosphate carboxylase oxygenase (RuBisCO) in intact leaves was preserved for up to 3weeks. At temperatures of 30-40°C, RuBisCO degradation occurred within 48h. Degradation was more pronounced in shredded leaves. In 0.8-m3 storage bins at ambient temperature, core temperatures rapidly increased, up to 25°C in intact leaves and up to 45°C in shredded leaves within 2-3 days. Immediate storage at 5°C greatly suppressed the temperature increase in intact but not in shredded leaves. The indirect effect of excessive wounding, that is, heat production, is discussed as the pivotal factor responsible for increased degradation of protein. For optimal retention of soluble protein levels and quality in harvested sugar beet leaves, it is advised to minimize wounding and to store the material at temperatures around -5°C. PRACTICAL APPLICATION: To preserve the soluble protein content and quality for at least 3weeks, sugar beet leaves should be harvested with minimal wounding and stored at temperatures between 1 and 5°C. When aiming to store minimally wounded leaves in larger volumes, it must be ensured that the product temperature in the core of the biomass meets the temperature criterium or the cooling strategy must be adjusted. The principles of minimal wounding and low temperature storage are transferable to other leafy crops that are harvested for food protein.

Uptake of heavy metals by crops near a mining field: Pathways from roots and leaves

Metal uptake and distribution in crops have been demonstrated to be highly variable and depending on the metal of interest and the crop type. However, no consensus is reached regarding the primary factor controlling metal uptake in crops. This study thus comparably investigated Hg, As, Zn, Pb, Cd and Cu uptake and distribution in three crops grown in a watershed near a copper mining field located in Yunnan, Southwestern China. The bioconcentration factor (BCF) and translocation factor (TF) were statistically compared for the same metal across different crops. Leafy crops had a stronger propensity to accumulate Hg, As and Zn than fruit crops. The ability of grain crops to accumulate Cd and Cu was much lower than leafy and fruit crops. The three crops all tended not to accumulate Pb in their edible tissues. The DTPA extracted metal concentrations were not statistically correlated with the metal concentrations in crop edible tissues. It is thus not practical to predict metal uptake of Hg, As, Pb and Zn through their available concentrations in soils. The contents of nitrogen and phosphorus, and competing metal ions present in paddy soil decreased the accumulation of Cu and Cd in rice grains. By means of hierarchical cluster analysis, the high accumulation of Zn in the edible tissues of fruit and grain crops was mainly due to dust inputs via phloem transport from leaves. This is why BCF(Zn) was the highest among the six metals for these two crops. For leafy crops, the accumulation of Hg, Cd and Zn in leaves was mainly through soil inputs by roots. Our findings serve as a scientific basis for the selection of crops in areas with high background of heavy metals.

Evaluation of Growth Responses of Lettuce and Energy Efficiency of the Substrate and Smart Hydroponics Cropping System.

Smart sensing devices enabled hydroponics, a concept of vertical farming that involves soilless technology that increases green area. Although the cultivation medium is water, hydroponic cultivation uses 13 ± 10 times less water and gives 10 ± 5 times better quality products compared with those obtained through the substrate cultivation medium. The use of smart sensing devices helps in continuous real-time monitoring of the nutrient requirements and the environmental conditions required by the crop selected for cultivation. This, in turn, helps in enhanced year-round agricultural production. In this study, lettuce, a leafy crop, is cultivated with the Nutrient Film Technique (NFT) setup of hydroponics, and the growth results are compared with cultivation in a substrate medium. The leaf growth was analyzed in terms of cultivation cycle, leaf length, leaf perimeter, and leaf count in both cultivation methods, where hydroponics outperformed substrate cultivation. The results of the 'AquaCrop simulator also showed similar results, not only qualitatively and quantitatively, but also in terms of sustainable growth and year-round production. The energy consumption of both the cultivation methods is compared, and it is found that hydroponics consumes 70 ± 11 times more energy compared to substrate cultivation. Finally, it is concluded that smart sensing devices form the backbone of precision agriculture, thereby multiplying crop yield by real-time monitoring of the agronomical variables.

An Economic Analysis of Medicinal Herb Colocasia for Leaf Production

Objective: To study the level of input use in colocasia production, estimate the cost and return and disposable pattern. Colocasia herb is rich source of phenols, flavonoids, saponins, tannins, glycosides, sterols and triterpenoids, therefore, used as traditional medicaments. Farmers cultivate this multi cut crop only for leaf production in middle Gujarat. Methods: This leafy crop production mainly depends upon the level of input used. Hence, the use of judicious inputs (nutritional and irrigation) in production process is vital in this multi cut crop cultivation. Results: Average gross return (Rs. 486454.45 ha-1) and net return (Rs. 293452.22 ha-1) were obtained by producers. Price received by farmers at field level was Rs. 2309.20 q-1 and the cost of production (Rs./q) of colocasia was the tune of Rs. 1020.20. This indicated that price received by producers was higher as compared to the cost incurred by them. The total marketing cost incurred by all the middlemen in the identified channel was about Rs. 844.77 q-1. Out of which the highest cost was incurred by village trader followed by retailer, wholesaler cum commission agent and farmer. Average total margin earned by different functionaries was Rs. 3969.39 q-1 and the margin was higher at retailers’ level (Rs. 2182.50 q-1) as compared to village trader (Rs. 1245.23) and wholesaler-cum-commission agents (Rs 541.66 q-1). The producer’s share in consumer’s rupee was quite low (32.35 per cent) and the price spread was Rs. 4814.16 q-1 in the identified marketing channel of colocasia in study area. Conclusion: Overall, colocasia is the remunerative crop for the farmers and needs to shorten the marketing channel.