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An effective strategy for enhancing fruit production continuity during extended sweet pepper season involves adopting innovative biostimulants such as potassium silicate (PS) and vinasse. Adjusting PS and vinasse concentrations are crucial for maintaining the balance between vegetative and fruit growth, particularly in sweet pepper with a shallow root system, to sustain fruiting over prolonged season. However, the interaction between PS and vinasse and the underlying physiological mechanisms that extend the sweet pepper season under greenhouse conditions remain unclear. This study aimed to investigate the impact of PS and vinasse treatments on the yield and biochemical constituents of perennial pepper plants cultivated under greenhouse conditions. For two consecutive seasons [2018/2019 and 2019/2020], pepper plants were sprayed with PS (0, 0.5, and 1 g/l) and drenched with vinasse (0, 1, 2, and 3 l/m3). To estimate the impact of PS and vinasse on the growth, yield, and biochemical constituents of pepper plants, fresh and dry biomass, potential fruit yield, and some biochemical constituents were evaluated. Results revealed that PS (0.5 g/l) coupled with vinasse (3 l/m3) generated the most remarkable enhancement, in terms of plant biomass, total leaf area, total yield, and fruit weight during both growing seasons. The implementation of vinasse at 3 l/m3 with PS at 0.5 and 1 g/l demonstrated the most pronounced augmentation in leaf contents (chlorophyll index, nitrogen and potassium), alongside improved fruit quality, including total soluble solid and ascorbic acid contents, of extended sweet pepper season. By implementing the optimal combination of PS and vinasse, growers can significantly enhance the biomass production while maintaining a balance in fruiting, thereby maximizing the prolonged fruit production of superior sweet pepper under greenhouse conditions. [ABSTRACT FROM AUTHOR]

Aims: Plant-beneficial fungi play an important role in enhancing plant growth and protecting plants from biotic and abiotic stresses. However, context-dependency of such effects and differences among fungi often lead to inconsistent results that hamper their widespread use. Here, we investigated the effect of plant-beneficial fungi on plant growth and herbivore resistance, and how effects are mediated by fertilization. Methods: Sweet pepper (Capsicum annuum L.) plants were root-inoculated with the plant-beneficial fungi Beauveria bassiana ARSEF 3097 and Trichoderma harzianum T22 and grown in a low-nutrient potting mix, with or without additional nutrients. Plant growth and herbivore resistance against the southern green stink bug (Nezara viridula L.) were compared between fungal treatments and fertilization levels by measuring several growth traits and quantifying feeding damage and plant defense-related gene expression. Results: Fertilization significantly increased plant growth, but at the same time made plants more susceptible to herbivory. Irrespective of fertilization, T. harzianum stimulated growth and reduced feeding damage (number of leaf punctures), while B. bassiana only enhanced growth. For both strains, fungal inoculation generally increased the expression of marker genes involved in salicylic acid- and jasmonic acid-dependent defense responses upon herbivory, but this was less pronounced for salicylic acid-dependent defense signaling under fertilization. Conclusions: We conclude that fungal inoculation improved plant growth and generally elicited a stronger defense response to stink bug feeding. Accordingly, plant damage was reduced by T. harzianum. Overall these results show that plant-beneficial fungi have the potential to promote plant growth and reduce feeding damage, irrespective of fertilization. [ABSTRACT FROM AUTHOR]

Sweet peppers are popular worldwide due to their nutrition and taste. Conventional vegetable tracing methods have been trialed, but the application of such labels or tags can be laborious and expensive, making their commercial application impractical. What is needed is a label-free method that can identify features unique to each individual fruit. Our research team has noted that sweet peppers have unique textural fluorescence features when observed under UV light that could potentially be used as a label-free signature for identification of individual fruit as it travels through the postharvest supply chain. The objective of this research was to assess the feature of these sweet pepper features for identification purposes. The macroscopic and microscopic images were taken to characterize the fluorescence. The results indicate that all sweet peppers possess dot-like fluorescence features on their surface. Furthermore, it was observed that 93.60% of these features exhibited changes in fluorescence intensity within the cuticle layer during the growth of a pepper. These features on the macro-image are visible under 365 nm UV light, but challenging to be seen under white LEDs and to be classified from the fluorescence spectrum under 365 nm light. This research reported the fluorescence feature on the sweet pepper, which is invisible under white light. The results show that the uniqueness of fluorescent features on the surface of sweet peppers has the potential to become a traceability technology due to the presence of its unique physical modality. [ABSTRACT FROM AUTHOR]

The efficacy of alkaline extracts from Acanthophora spicifera, Gracilaria ornata, Codium taylorii, Caulerpa serrulata, and Sargassum vulgare was assessed both in vitro and in planta under greenhouse conditions. Seaweeds were collected from the coast of Trinidad, WI. Alkaline extracts were tested for their efficacy in promoting plant growth and performance in tomato (Solanum lycopersicum, Hybrid-61) and sweet pepper (Capsicum annuum, Amrit) and for their efficacy in controlling infections caused by Alternaria solani and Xanthomonas campestris pv. vesicatoria. Germination assays indicated that seed bio-priming with seaweed extracts lead to a significant increase in seed germination percentage (up to 21.7%), germination index (up to 21.86%) and seedling vigour index (up to 105.8%) compared to hydro-primed seeds. Mean germination time was also significantly reduced (up to 40.6%) in seaweed bio-primed seeds. Chlorophyll and carotenoid contents significantly increased (up to 18.3 and 42.5%, respectively) in seedlings that were bio-primed with seaweed extracts. Greenhouse trials showed that plants foliar sprayed with 0.5% v/v seaweed extract had significantly fewer incidences of bacterial spot (22.9–49.1% and 24.6–49.2% for sweet pepper and tomato, respectively) and early blight (32.8–48.3% and 31.9–47.5% for sweet pepper and tomato, respectively). Furthermore, seaweed extract treatments caused a significant increase in the fruit yield of tomato (118.2-181.8%) and sweet pepper (47.1–70.6%). In vitro antimicrobial assay revealed that all seaweed extracts had no direct antimicrobial effect against a panel of phytopathogens. However, upon foliar treatments with the extracts, the DNA levels of A. solani and X. campestris pv. vesicatoria were significantly lower compared to the controls. Seaweed extract-treated tomato and sweet pepper plants had significantly higher activities of chitinase, peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, glucanase and higher levels of total phenols. Concurrently, the upregulation of marker genes involved in the salicylic acid, jasmonic acid, and ethylene-mediated defence pathways was also observed in seaweed extract-treated plants. The above results point towards the elicitor-like activity of seaweed extracts on plants' metabolic processes. This study, therefore, highlights the beneficial effects of extracts from Caribbean seaweeds and thus supports their potential use in plant systems as a sustainable crop input. [ABSTRACT FROM AUTHOR]

Agrochemicals provide vital nutrients for plant growth to enhance crops yield, but they can pose major agro-environmental issues. Bioinoculants have attracted more and more attention due to their cost effective-eco-friendly and pollution-free characteristics. The aim of this study was to determine whether using a variety of bioinoculants that include both individual and group members could reduce the need for chemical fertilizer. In the modern era, individual and multiple strain formulation as bioinoculants and bacterial consortium is need of agricultural sustainability. A total 132 bacteria were sorted out from soil and internal tissues of the plant and screened for PGP characteristics including nitrogen fixer, phosphorus, and potassium solubilization. Among 132 bacteria, 13 were found to fix nitrogen, 17 and 14 bacteria were able to solubilize phosphorus, and potassium respectively. Efficient bacterial isolates were identified using 16S rRNA gene sequencing as Bacillus thuringiensis EU-CRP-15 (P-solubilizer), Bacillus horikoshii EU-CRK-18 (K-solubilizer), and Pseudomonas trivialis EU-CEN-2 (N-fixer). Inoculation of individual and consortium bioinoculants had a favorable effect on seed sprouting with the increase concentrations of inoculum. These three compatible and individual bacterial strains inoculated on sweet pepper enriched the growth and physiological characteristic of plant (plant length, root length, fresh weight, and biomass of the plant), and (chlorophyll, carotenoids, flavonoids, phenolics, and total soluble sugar content) over chemical fertilizers and untreated control plant. The plant growth promoting bacteria viz; N2-fixer as well as P and K solubilizers can be utilized as bioinoculants for the growth promotion of plants and increasing soil fertility. [ABSTRACT FROM AUTHOR]

Cladosporium rot (Cladosporium cladosporioides) is a common disease affecting sweet pepper postharvest. Rots are frequently observed in Mediterranean growing regions, and conidia produced during refrigerated transport and storage can spread readily in air currents or by direct contact with healthy fruits. There are limited management strategies that are used to control Cladosporium rot that include protecting fruits from physiological disorders and limiting wounding. The objective of our research was to characterize C. cladosporioides isolates from sweet pepper in Israel and to determine isolate sensitivity to the fungicide fludioxonil. Isolates collected from multiple regions in Israel were slow growing and formed olivaceous-grey to brown colonies on PDA. The conidia measured 5.1 × 3.1 µm and ramoconidia measured 15.4 × 3.3 µm. The optimum temperature was 20 °C for mycelial growth and conidial germination, and limited fungal growth occurred at 1 and 30 °C. Fruit extracts enhanced conidial germination, while there was no effect of fruit surface exudates. In histological sections from diseased pepper, hyphae had ramified through the inner pericarp layer by 24 h post inoculation (hpi) and dissolution of the cytoplasm occurred by 72 h. Sporulation from the hyphal layer and diseased tissue was observed 96 hpi. On fludioxonil amended media the average EC50 was 0.19 ppm for the isolates tested, suggesting this fungicide could be beneficial in disease management programs. [ABSTRACT FROM AUTHOR]

Accurate and highly sensitive analysis of folpet and captan was accomplished using liquid chromatography-triple quadrupole linear ion trap mass spectrometry (LC-QqQIT) with selective ion mode; mass filtering, collision, and trapping condition. Dimensional mass spectrometry (MS3) parameters were optimized for the residue detection of folpet and captan in six food commodities (apples, tomatoes, sweet pepper, wheat flour, sesame seeds, and fennel seeds). The sample preparation method was based on the known QuEChERS protocol, except a mixture of acetonitrile/acetone was used for the sample extraction from the sesame seeds. The robustness and reliability of the developed MS3 method were demonstrated by performing a full validation, according to SANTE/11312/2021, at 0.01–0.25 mg/kg. Recovery ranged from 83 to 118% with a relative standard deviation below 19% in all the tested commodities, and limits of quantifications (LOQs) were 0.01 mg/kg in apples and tomatoes; 0.03 mg/kg in sweet pepper; and 0.05 mg/kg in wheat flour, sesame seeds, and fennel seeds. Monitoring results showed that about 90% of apples contained captan residue, and in sweet pepper, concentrations of captan and folpet as high as 1.57 and 0.97 mg/kg were found, respectively. The novel developed MS3 method enabled more reliable identification of these commonly problematic fungicides at lower LOQs than previously reported methods. [ABSTRACT FROM AUTHOR]

The poinsettia thrips, Echinothrips americanus Morgan (Thysanoptera: Thripidae), is a key pest of various ornamental and vegetable greenhouse crops. As current biological control alternatives lack efficiency, applying chemicals remains the dominant control strategy, thereby heavily disturbing the biocontrol-based integrated management of other pests. For a range of other thrips pests, phytoseiid predatory mites have shown to be effective biocontrol agents, being able to overcome the thrips' physical and chemical defense armory. Here, we investigated potential underlying causes for the lack of phytoseiid efficacy in controlling E. americanus. First, we assessed the nutritional value of E. americanus for the predatory mite Amblydromalus limonicus (Garman and McGregor) (Acari: Phytoseiidae) when its physical or chemical defenses were eliminated by freezing the thrips. The phytoseiid could complete its immature development when frozen thrips instars were offered, but not when these were offered alive. Subsequently, we tested whether adult female A. limonicus had a higher predation rate on first instar E. americanus when they had been given experience with either live or frozen E. americanus during their immature development (i.e., conditioning). Conditioning significantly increased the predation capacity of the phytoseiid. Finally, we tested the control potential of conditioned A. limonicus versus naïve ones when exposed to E. americanus on sweet pepper plants. In contrast to the laboratory trials, at the plant level, conditioning did not yield better control. Possible factors explaining insufficient control of E. americanus by phytoseiids are discussed. [ABSTRACT FROM AUTHOR]

The combination of a companion plant with a cultivated plant is considered an interesting strategy to reduce pest pressure and, hence, the use of pesticides. Although several plants from the Alliaceae and Lamiaceae families are known to be efficient companion plants against aphid pests, only a few plants of the Geraniaceae family have been studied so far. The aim of this work was to investigate the potential effects of Geranium macrorrhizum as a companion plant on the colonization of sweet pepper (Capsicum annuum, Solanaceae) by the green peach aphid (Myzus persicae). Aphid's orientation behavior, probing behavior and life history traits were assessed on sweet pepper using a host choice preference setup, Electrical Penetration Graph technique and clip-cage laboratory bioassays, respectively. The potential disturbance through mechanical stimulation of geranium leaves was also assessed. The composition of VOCs from G. macrorrhizum leaves was analyzed using SPME technic followed by GC–MS. This study revealed that G. macrorrhizum as a companion plant was intrinsically repellent but not enough to completely mask the attractive odor of the sweet pepper host plant. Moreover, G. macrorrhizum negatively impacted the probing behavior, fecundity and survival rate of M. persicae on sweet pepper. The effects were exacerbated when G. macrorrhizum leaves were mechanically stimulated. This could be due to the greater amount of the main VOCs germacrone and β-elemenone emitted by G. macrorrhizum following mechanical stimulation. Our results bring new insights into the use of novel companion plants to regulate aphid pest populations. [ABSTRACT FROM AUTHOR]

Red pepper (Capsicum annuum L. cv. Capia) is an important vegetable obtained from a 1-year cultivated plant belonging to the Solanaceae family. Among the products of red pepper, its paste is very similar to tomato paste in appearance; however, it differs in terms of flavor properties. The wide-ranging quality parameters (dry matter, soluble solids, pH, titration acidity, salt, insoluble ash, total reducing sugars, color values, total carotenoid, antioxidant properties, browning index, and 5-hydroxymethylfurfural) of commercial sweet pepper pastes (n = 52) were determined. To the best of our knowledge, this study is the most comprehensive study on determining the quality parameters of red pepper paste, and its in-depth results will help food authorities issue registrations related to commercial pepper paste in countries such as Türkiye. Additionally, near-infrared (NIR) spectroscopy-based machine-learning algorithms were evaluated for the first time in paste samples as a rapid alternative or complementary to the conventional analytical methods. Regarding the conditional entropy-based models, successful predictions with high accuracy were developed for all the quality parameters of pepper paste. Except for the coefficient of determination value of 0.69 and 0.85 in the prediction of HMF and a/b color values in the developed models, respectively, 0.96 or higher coefficients of determination were obtained for all other parameters. Therefore, NIR spectroscopy, along with the conditional entropy-based predictions, enables simple, fast, multiparametric and accurate quantitative prediction of the numerous quality parameters for commercial sweet pepper pastes and has the potential to be used in routine quality control analyses by pepper paste producers. [ABSTRACT FROM AUTHOR]

Automatic and accurate recognition of the parts to be picked is the key to realize the intelligent picking of sweet pepper. However, pepper fruits are always covered by other organs, and small objects such as stems and shoots are difficult to be recognized by machines or cameras under certain extreme conditions. To accurately segment and recognize all kinds of objects in sweet pepper images captured at night, three experiments were performed in this paper, and an enhanced model based on convolutional neural networks was eventually achieved. In experiment I, several semantic segmentation networks were trained on a small data set, and the full-resolution residual network (FRRN) was taken as a primary network. Then, the impact of resolution of input images on the segmentation effect was investigated in experiment II. To strengthen the feature presentation of inconspicuous objects, the position attention module was appended on top of the FRRN in experiment III. This architecture was further trained to provide more precise segmentation results. The experimental result shows that the mean intersection over union is 78.88%, which is at least 1.94% points higher than other models, and the mean pixel accuracy is 97.94% on the test set. The proposed method has higher generalization performance when facing unforeseen picking situations; meanwhile, it is generic and can be applied to other fruits and vegetables. [ABSTRACT FROM AUTHOR]

Understanding and prediction of mercury (Hg) phytoavailability in vegetable–soil systems is essential for controlling food chain contamination and safe vegetable production as Hg-contaminated soils pose a serious threat to human health. In this study, four typical Chinese soils (Heilongjiang, Chongqing, Yunnan, and Jilin) with varied physicochemical properties were spiked with HgCl2 to grow sweet pepper (Capsicum annuum L.) in a pot experiment under greenhouse condition. The chemical fractionation revealed a significant decrease in exchangeable Hg, while an increase in organically bound Hg in the rhizosphere soil (RS) compared to bulk soil (BS). This observation strongly highlights the vital role of organic matter on the rhizospheric Hg transformation irrespective of contamination levels and soil properties. Stepwise multiple linear regression (SMLR) analysis between Hg concentration in plants, Hg fractions in RS and BS, and soil properties showed that Hg in plant parts was significantly influenced by soil total Hg (THg) (R2 = 0.90), soil clay (R2 = 0.99), amorphous manganese oxides (amorphous Mn) (R2 = 0.97), amorphous iron oxides (amorphous Fe) (R2 = 0.70), and available Hg (R2 = 0.97) in BS. Nevertheless, in the case of RS, Hg accumulation in plants was affected by soil THg (R2 = 0.99), amorphous Mn (R2 = 0.97), amorphous Fe oxides (R2 = 0.66), soil pH, and organically bound Hg fraction (R2 = 0.96). Among all the evaluated soils (n = 04), metal (mercury) concentration in terms of plant uptake was reported highest in the Jilin soil. Based on SMLR analysis, the results suggested that the phytoavailability of Hg was mainly determined by THg and metal oxides regardless of the rhizospheric effect. These findings facilitate the estimation of Hg phytoavailability and ecological risk that may exist from Hg-contaminated areas where pepper is the dominant vegetable. [ABSTRACT FROM AUTHOR]

We studied the effect of 16- and 24-h photoperiods on mitochondrial respiration in the darkness (RDark), in the light (RLight), their ratio RLight/RDark (reflecting the degree of inhibition of respiration by light), and the ratio of respiration to gross photosynthesis (Ag) in Solanaceae plants: eggplant (Solanum melongena L.), sweet pepper (Capsicum annuum L.), and tomato (Solanum lycopersicum L.). The leaf RLight rate was lower than RDark, regardless of plant species and photoperiod. At a 16-h photoperiod, light inhibited up to 19, 31, and 34% of respiration, respectively, in eggplant, sweet pepper, and tomato. Continuous lighting increased the degree of light inhibition of respiration to 36 and 46% in eggplant and sweet pepper but did not affect this value in tomato. An increase in respiration inhibition could be associated with structural changes in the leaf and a decrease in the oxygenase activity of RuBisCO/O. Continuous lighting reduced Ag to a greater extent than RDark and RLight, reflecting a shift in the carbon balance towards losses. Increase in RDark/Ag and RLight/Ag ratios, due to a significant decrease in the photosynthetic activity with a relative stability of the respiratory metabolism, may reflect the negative effect of continuous lighting on the productivity of the studied species. The obtained results also showed that the photoperiod duration can be one of the environmental factors influencing the degree of light inhibition of respiration. [ABSTRACT FROM AUTHOR]

Shades are adjusted in sweet pepper cultivation, based on solar exposure levels. Pyranometers and photosensitive films have recently been introduced to smart agriculture. However, there are no means of observing biological responses to solar exposure. In this study, we hypothesized that solar exposure levels affect the visible autofluorescence of sweet pepper under 365 nm illumination. To test this hypothesis, we cultivated sweet pepper plants under two exposure conditions, low (half of the normal) and high (the normal). Fluorescence photography (365 nm illumination) revealed that dark-fluorescent peppers only arise when cultivated under high-exposure conditions (0.7-fold decline at emission of 390 nm for high-exposure conditions). Microscopic and spectroscopic observations showed that blue autofluorescence was accompanied by an accumulation of UVB pigments (1.2-factor increase in the absorbance at 300 nm) and epidermal development (1.3-fold thicker cell wall). This study suggests that the autofluorescence of sweet pepper can possibly be used to understand the response of crop to solar radiation at a fruit level in horticulture. [ABSTRACT FROM AUTHOR]

Key Message: Unstable Restorer-of-fertility (Rfu), conferring unstable fertility restoration in the pepper CGMS system, was delimited to a genomic region near Rf and is syntenic to the PPR-like gene-rich region in tomato. The use of cytoplasmic-genic male sterility (CGMS) systems greatly increases the efficiency of hybrid seed production. Although marker development and candidate gene isolation have been performed for the Restorer-of-fertility (Rf) gene in pepper (Capsicum annuum L.), the broad use of CGMS systems has been hampered by the instability of fertility restoration among pepper accessions, especially sweet peppers, due to the widespread presence of the Unstable Restorer-of-fertility (Rfu) locus. Therefore, to investigate the genetic factors controlling unstable fertility restoration in sweet peppers, we developed a segregation population (BC4F5) from crosses using a male-sterile line and an Rfu-containing line. Segregation did not significantly deviate from a 3:1 ratio for unstable fertility restoration to sterility, indicating single dominant locus control for unstable fertility restoration in this population. Genetic mapping delimited the Rfu locus to a 398 kb genomic region on chromosome 6, which is close to but different from the previously identified Rf-containing region. The Rfu-containing region harbors a pentatricopeptide repeat (PPR) gene, along with 10 other candidate genes. In addition, this region is syntenic to the genomic region containing the largest number of Rf-like PPR genes in tomato. Therefore, the dynamic evolution of PPR genes might be responsible for both the restoration and instability of fertility in pepper. During genetic mapping, we developed various molecular markers, including one that co-segregated with Rfu. These markers showed higher accuracy for genotyping than previously developed markers, pointing to their possible use in marker-assisted breeding of sweet peppers. [ABSTRACT FROM AUTHOR]

To increase nitrogen (N) use efficiency and reduce water pollution from vegetable production, it is necessary to optimize N management. Fluorescence-based optical sensors are devices that can improve N fertilization through non-destructive field monitoring of crop variables. The aim of this work was to compare the performance of five fluorescence indices (SFR-R, SFR-G, FLAV, NBI-R, and NBI-G) to predict crop variables, as dry matter production, crop N content, crop N uptake, Nitrogen Nutrition Index (NNI), absolute and relative yield, in sweet pepper (Capsicum annuum) crops grown in greenhouse. Fluorescence measurements were periodically made with the Multiplex® 3.6 sensor throughout three cropping cycles subjected to five N application treatments. The performance of fluorescence indices to predict crop variables considered calibration and validation analyses. In general, the five fluorescence indices were strongly related with NNI, crop N content and relative yield. The best performing indices to predict crop N content and NNI at the early stages of the crops (i.e., vegetative and flowering phenological stages) were the SFR indices, both under red (SFR-R) and green (SFR-G) excitation. However, in the final stage of the crop (i.e., harvest stage), the best performing indices were NBI, both under red (NBI-R) and green (NBI-G) excitation, and FLAV. The two SFR indices best predicted relative yield of sweet pepper at early growth stages. Overall, the fluorescence sensor and the fluorescence indices evaluated were able to predict crop variables related to N status in sweet pepper. They have the capacity to be incorporated into best N management practices. [ABSTRACT FROM AUTHOR]

Damage potential of green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), on sweet pepper, Capsicum annuum Linnaeus, under protected environment was assessed by artificially releasing different aphid densities (1, 2, 4 and 8 aphids/ plant) at 30 and 60-days after transplanting coinciding with vegetative and flowering/ fruiting crop growth stage. Aphids were restricted to feed for 30 days (limited exposure duration) as well as throughout crop growth stage (unlimited exposure duration). Myzus persicae infestation exhibited varying levels of stunting effects on plant growth. Aphid infestation also reduced marketable yield, being more pronounced at higher infestation levels of 4 and 8 aphids. Infestation initiated in vegetative stage resulted in lower yield as compared to the infestation initiated in later growth stages. Loss in marketable yield varied from 31.49 to 76.20 and 30.63 to 100 per cent in summer and autumn season crops, respectively. Relationship deduced between reduction in yield and cumulative aphid days (CADs) under unlimited exposure duration depicted per unit increase in CADs to reduce marketable fruit yield to the extent of 0.01 and 0.027 g for the infestation initiated in vegetative and later growth stages, respectively. Corresponding reduction in fruit yield on the basis of initial aphid infestation levels (AILs) was 165.3 and 129.9 g/ plant/ aphid level. Economic injury level of M. persicae worked out for the infestation initiated in vegetative and flowering/ fruiting stage to be 3862 and 1464 CADs whereas on the basis of AILs it was 0.25 and 0.31 aphids/ plant for the infestation initiated in corresponding crop stages. [ABSTRACT FROM AUTHOR]

Recent years have witnessed an increased interest in the cultivation and consumption of peppers. Therefore, new solutions are being sought to provide pepper plants with the most favorable conditions for growth and development. In view of the above, the aim of this study was to evaluate the effect of selected biostimulants on the biometric parameters, yield and nutritional value of Capsicum annuum fruit. The research hypothesis postulates that biostimulants can increase the yield and improve the nutritional quality of pepper fruit. The experiment was conducted in an unheated plastic tunnel. The experimental materials comprised three sweet ('Solario F1', 'Turbine F1' and 'Whitney F1') and two hot ('Cyklon' and 'Palivec') cultivars of C. annuum. It was found that the combined application of environmentally-friendly microbial-based biostimulants (BB Soil, BB Foliar, Multical, MK5 and Biocin F) did not clearly improve the morphological traits of pepper fruit, yield or the concentrations of sugars and organic acids in fruit, therefore their use is not economically justified. Hot peppers had a higher content of dry matter, total sugars and L-ascorbic acid than sweet peppers. The analyzed biostimulants increased nitrate (V) concentrations in the fruit of both hot and sweet peppers. 'Turbine F1' and 'Solario F1' were particularly prone to nitrate (V) accumulation in fruit, therefore the use of biostimulants should be limited in their cultivation. Pepper fruits with the largest horizontal diameter and the thickest skin should be preferred because these traits are associated with high sugar content. [ABSTRACT FROM AUTHOR]

Background: Two separate experiments were conducted in the minor season from September to November, 2019 and major season from March to May, 2020 to determining the type of soil amendment and transplanting age that can best improve the post-harvest quality and shelf life of sweet pepper fruits at Benso oil palm plantation of Adum Banso Estate in the Mpohor District of the Western Region of Ghana. The experiments were conducted as a 4 × 2 factorial, arranged in a Randomized Complete Block Design. Four fertilizer treatments including no fertilizer (control), 10 tons/ha of poultry manure, 300 kg/ha of NPK 15-15-15 and 5 t/ha of poultry manure + 150 kg/ha of NPK 15-15-15 and two ages of transplants including 6-week-old seedlings and 7-week-old seedlings were applied during the cultivation periods and were later evaluated of their effects on the post-harvest quality and shelf life of harvested fruits after a two-weeks storage period. Data collected on weight loss, shrinkage, decayed fruits and shelf life of harvested fruits were subjected to analysis of variance using the Genstat Statistical package. The least significant difference criterion was used to separate treatment means at 5% probability. Results: Post-harvest qualities of sweet pepper fruits were not significantly influenced by age of transplant throughout the study. Fertilizer application generally increased percentage fruit weight loss, fruit shrinkage, fruit decay and reduced shelf life of sweet pepper fruits in the major season. Sole application of poultry manure mostly enhanced post-harvest quality of sweet pepper fruits in the minor rainy season, but fruit shelf life was improved if no fertilizer was applied. Application of a combination of poultry manure and NPK 15-15-15 to 6-week-old transplants gave relatively low fruit weight loss and shrinkage values. Generally, fruit quality and shelf life were enhanced in 6-week-old transplants treated with no fertilizer. Conclusions: The use of poultry manure alone should be encouraged to probably increase yield while improving the quality and shelf life of harvested sweet pepper fruits. Transplanting of 6-week-old seedlings is also encouraged for quality harvested fruits and extended shelf life. [ABSTRACT FROM AUTHOR]

Plant-associated bacteria play an important role in the enhancement of plant growth and productivity. Gluconacetobacter azotocaptans is an exceptional bacterium considering that till today it has been isolated and reported only from Mexico and Canada. It is a plant growth-promoting bacterium and can be used as biofertilizer for different crops and vegetables. The objective of the current study was to evaluate the inoculation effect of Gluconacetobacter azotocaptans DS1, Pseudomonas putida CQ179, Azosprillium zeae N7, Azosprillium brasilense N8, and Azosprillium canadense DS2, on the growth of vegetables including cucumber, sweet pepper, radish, and tomato. All strains increased the vegetables' growth; however, G. azotocaptans DS1 showed better results as compared to other inoculated and control plants and significantly increased the plant biomass of all vegetables. Therefore, the whole genome sequence of G. azotocaptans DS1 was analyzed to predict genes involved in plant growth promotion, secondary metabolism, antibiotics resistance, and bioremediation of heavy metals. Results of genome analysis revealed that G. azotocaptans DS1 has a circular chromosome with a size of 4.3 Mbp and total 3898 protein-coding sequences. Based on functional analysis, genes for nitrogen fixation, phosphate solubilization, indole acetic acid, phenazine, siderophore production, antibiotic resistance, and bioremediation of heavy metals including copper, zinc, cobalt, and cadmium were identified. Collectively, our findings indicated that G. azotocaptans DS1 can be used as a biofertilizer and biocontrol agent for growth enhancement of different crops and vegetables. [ABSTRACT FROM AUTHOR]

Thrips palmi, an important pest of vegetables and ornamentals, transmits several tospoviruses. Effect of tospovirus on host plant and vector is well studied. Little is known about the host-mediated alteration in biological traits of T. palmi. The present study reports the effect of different hosts viz. brinjal, cowpea, cotton, cucumber, sweet pepper, and tobacco on development, survival, fecundity, feeding, and vector competence of T. palmi. A higher net reproductive rate and lowest generation time were recorded in brinjal and cotton. Cowpea, tobacco, and sweet pepper reduced reproductive potential of T. palmi. Exposure to brinjal caused greater feeding by T. palmi, whereas it was least on sweet pepper. The vector competence of T. palmi was highest on cucumber and cowpea, however, tospovirus transmission was inhibited in brinjal and cotton. The alteration in biology could be due to the biochemical and morpho-physiological traits of hosts interfering with essential physiological processes of T. palmi. [ABSTRACT FROM AUTHOR]

The Bemisia tabaci (Gennadius) cryptic species complex is composed of important pest insects, with cryptic species Mediterranean (MED) and Middle East-Asia Minor 1 (MEAM1) having caused severe yield reduction on crops worldwide. The former was reported in Brazil in 2014, while the latter was first reported in the country in the 1990s. Although farmers have highly adopted insecticide application for B. tabaci management, its efficacy may vary among host plants and cryptic species. Cyantraniliprole is a new anthranilic diamide insecticide with a mode of action that activates the insect ryanodine receptor (RyR). In this context, the purpose of this study was to investigate the effects of cyantraniliprole spraying on the oviposition and performance of MEAM1 and MED cryptic species in tomato and sweet pepper plants. Cyantraniliprole caused high adult mortality for both cryptic species on sweet pepper (> 94%), while its efficacy was moderate for MEAM1 (~ 56%) and low for MED (~ 12%) on tomato. MED laid more eggs on sweet pepper and tomato treated with water and cyantraniliprole, respectively, than MEAM1. Additionally, cyantraniliprole reduced the hatchability of MED and MEAM1 on sweet pepper and tomato, respectively. Moreover, MED showed better performance than MEAM1 regardless of the treatment and host plant, except on tomato treated with water. Our results indicate that cyantraniliprole efficacy changes according to B. tabaci cryptic species and host plant. These findings will be important for redesigning cyantraniliprole doses for B. tabaci management in Brazil. [ABSTRACT FROM AUTHOR]

A comprehensive quality evaluation was performed on dried sweet bell pepper samples obtained from two years of production, two genotypes and two drying technologies, using one conventional and two organic cropping systems. A total number of 35 quality indexes, comprising non-volatile and volatile flavor compounds and health related compounds were evaluated for their possible role in the flavor of dried bell pepper: the most significant variations in the data analysis due to the year, drying technique, genotype and cropping system resulted in 25, 25, 16 and 10 significant interactions, respectively. The PCA analysis confirmed the main role of drying technique and sampling year. The malic acid for non-volatile compounds, linalool and 2-methoxy-3-isobutylpyrazine for volatiles represent the most relevant chemical indexes significantly correlating with many sensory descriptors scored by panellists, and are, therefore, proposed as quality markers to be carefully monitored for a correct quality evaluation of dried bell pepper. [ABSTRACT FROM AUTHOR]

Garden nasturtium (Tropaeolum majus), belonging to the family Tropaeolaceae, is a widely used ornamental plant. In April 2020, a powdery mildew was observed on garden nasturtium in central Taiwan. Symptoms included angular chlorotic lesions which later became brown and necrotic on both leaf surfaces. The fungus was identified as Leveillula taurica s. str. based on the morphology and the molecular analysis of ITS sequence. The powdery mildew was found on both T. majus and sweet pepper in the meantime. This is the first report of L. taurica causing powdery mildew on T. majus in Taiwan. [ABSTRACT FROM AUTHOR]

Background: Sweet pepper is considered one of the most important vegetable crops cultivated for local consumption and exportation. Under greenhouse conditions, the effects of different rates of yeast and compost tea on vegetative growth, leaves mineral content, fruit yield and quality were studied for two consecutive years 2018/2019 and 2019/2020 under soilless conditions. Nine treatments of compost tea (CT) and or dry yeast (DY) were applied using control (sprayed with distilled water); CT (10L/fed.); CT (20 L/fed.); DY (3 g/L); DY (6 g/L); CT (10L/fed.) + DY (3 g/L); CT (20L/fed.) + DY (3 g/L); CT (10L/fed.) + DY (6 g/L) and CT (20L/fed.) + DY (6 g/L). Results: Results showed that the mixture of compost tea and dry yeast at a rate of 20 L./fed. plus 6 g/L, respectively, had significantly increased vegetative growth, fruit physical quality (length, diameter and fresh weight), total yield, leaves mineral content (N, P and K) and fruit nutritional value content (calcium and vitamin C). The maximum return or profit comes from the CT (20 L/fed) + DY (6 g/L) followed by CT (20 L/fed) + DY (3 g/L.) Conclusion: It is clear that all treatments enhanced the yield and the fruit physical parameters of the studied plants as well as all treatments are economically feasible including the control treatment. However, looking at the Revenue/Cost ratio (R/C), one can find that the maximum net revenue comes from the mixture of CT (20 L/fed) plus DY (6 g/L) with a net revenue about 192.72 L.E./m2 and R/C ratio of 1.90, followed by CT (20 L/fed) + DY (3 g/L.). [ABSTRACT FROM AUTHOR]

An effective culture system for producing embryos was developed from isolated microspores of sweet pepper (Capsicum annuum L.). The present work aimed to define exogenous arabinogalactan proteins (AGPs) on the embryogenesis of sweet pepper under the growth environments of donor plants. The experiments were performed with the cultivars Arancia, California wonder, Californium, Camelot, Inspiration, Plato, and Taranto under three different growth environments of the donor plants. The impacts of the different numbers of sweet pepper ovaries (0, 5, 10, and 15) were evaluated on microspore embryogenesis of cultivars in a factorial design with five replications. The simultaneous application of 10 ovaries in stress (sucrose starvation; temperature) and induction media resulted in the highest embryogenesis of the seven aforementioned cultivars under field conditions. Also, the impacts of 0, 80, 120, and 200 mg L−1 gum arabic were studied on embryogenesis in stress and induction media. The treatments containing 120 mg L−1 gum arabic showed the highest embryogenesis across all cultivars, except the California Wonder cultivar in the field conditions. Also, the simultaneous impact of the number of ovaries and concentrations of gum arabic on embryogenesis were studied. A combination of ten ovaries and 120 mg L−1 gum arabic generated the highest embryogenesis in the majority of cultivars. The results revealed that ovaries of sweet pepper and gum arabic had a significant impact on the efficiency of microspore embryogenesis in sweet pepper plants under field conditions. [ABSTRACT FROM AUTHOR]

This article, published in the Journal of Plant Pathology, reports the first occurrence of bell pepper endornavirus (BPEV) in pepper plants in Syria and Lebanon. The researchers isolated total RNA from sweet pepper plants exhibiting virus-like symptoms in coastal regions of both countries and conducted RT-PCR tests. The results confirmed the presence of BPEV in 12 symptomatic samples and three asymptomatic samples. DNA sequencing revealed a high degree of similarity between the Syrian and Lebanese BPEV isolates and other known isolates. This study represents the first documentation of BPEV in pepper plants in the Middle East. [Extracted from the article]

Pungent traits caused by capsaicinoids are characteristic of chili peppers (Capsicum spp.), and the pungent-variable sweet chili pepper 'Shishito' (Capsicum annuum) is unique in being known for the pungency in fruits with few seeds. In the present study, we tried to clarify the relationship between the number of seeds and pungency in 'Shishito'. First, we investigated the pungency of 'Shishito' by simple sensory evaluations and quantifications of capsaicinoids by high-performance liquid chromatography. As a result, few-seeded fruits had a larger fluctuation of capsaicinoid content than many-seeded ones. This indicates that the number of seeds, in particular a decrease of the seeds, has some sort of connection with the pungency of 'Shishito'. Then, we analyzed the relationship between pungency and gene expression involving capsaicinoid biosynthesis at the individual fruit level. We vertically separated the placental septum in which capsaicinoids are synthesized and performed quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for 18 genes involved in capsaicinoid biosynthesis. We also used the placental septum for capsaicinoid quantification so that the gene expression levels and capsaicinoid contents in the same fruits were obtained, and their correlations were analyzed using 20 biological replicates. Among the 18 genes, expression levels of 11 genes (WRKY9, CaMYB31, AT3, BCAT, BCKDH, KAS I, KAS III, ACL, CaKR1, FAT, and pAMT) had a significant positive correlation with the capsaicinoid concentration, and they were considered to upregulate capsaicinoid biosynthesis. These results provide new insights regarding the environmental variation of the pungency traits in chili peppers and the relationship between pungency, the number of seeds, and gene expression involved in capsaicinoid biosynthesis. [ABSTRACT FROM AUTHOR]

Aims: Xanthomonas campestris pv. campestris (Xcc) survival was evaluated in the phyllosphere and rhizosphere of 20 crop species, as well as in the rhizosphere of cabbage cultivated in six soil types. Methods: The crops aerial parts were inoculated, and the rhizosphere soil was infested with bacterial suspension (107 CFU.mL−1) of 3098C Xcc strain, which is rifampicin-resistant and pathogenic to brassica plants. Xcc recovery from the samples was performed in a semi-selective culture medium. Results: The highest average survival periods of Xcc in the phyllosphere were obtained from cabbage (70 days), tomato (67 days), wheat and pumpkin (63 days), black oat and radish (56 days) and sweet pepper (49 days). Low Xcc survival occurred in the rhizosphere of most crops evaluated when compared to the soil in the absence of plants. The highest average period of survival in the rhizosphere was observed for cabbage (53 days). Survival periods in lettuce, pumpkin, wheat and mustard ranged from 21 to 28 days. In the rhizosphere of cabbage cultivated in six soils, survival periods ranged from 8 to 17 days. Conclusions: Sunflower, carrot, zucchini, spinach, sunn hemp, sorghum, maize and chive are recommended for rotating systems with brassicas because Xcc showed low survival in the phyllosphere and rhizosphere of these crops. [ABSTRACT FROM AUTHOR]

Tomato leaf miner, Tuta absoluta is a ravaging pest of tomato in many countries of the world including Tanzania. The pest inflicts substantial damage to tomato crop that causes a huge loss to farmers. This study focused on evaluating potentials of shared volatiles emanated from four hosts of the pest, namely tomato, aubergine, sweet pepper and watermelon in formulating attractant for female T. absoluta. Y-tube olfactometer was used to evaluate attractiveness of leaf volatiles from four hosts and a blend of shared compounds and GC-MS was used to identify volatile constituents of the four hosts. Results indicate that, female T. absoluta were attracted to volatiles of tomato volatiles (χ2 = 4.9, P < 0.05) and repelled by watermelon volatiles (χ2 = 6.4, P < 0.05). We further observed high composition of terpenes in tomatoes (70%) as compared to other hosts, which might have contribute to its observed attraction compared to the other hosts. On the other hand, watermelon was highly constituted by green leaves volatiles (GLVs) which is suggested to account for the observed repellency. Thus, shared compounds that do not contain GLVs significantly attracted female T. absoluta at a dose of 10 μl (χ2 = 8.1, P < 0.05). Our findings have revealed that, compounds shared by hosts attract females T. absoluta. Therefore, results from this study have laid groundwork in the development of attractant for management and monitoring of the pest. [ABSTRACT FROM AUTHOR]

This is a report of the natural occurrence of Capsicum frutescens (cayenne pepper) and Capsicum annuum L. (sweet pepper) infection with pepper mild mottle virus (PMMoV) in Indonesia, which was detected serologically via dot-immunobinding assay and confirmed by RT-PCR of the coat-protein–encoding gene and DNA sequencing. Phylogenetically, the cayenne and sweet-pepper isolates were closely related to Capsicum spp. isolates from Turkey, Italy and Korea, with 99.1%–99.5% and 100% identity at the nucleotide and amino acid levels, respectively. [ABSTRACT FROM AUTHOR]

Peppers are one of the most widely processed and consumed vegetables in the world. The present study was established to obtain phenolic profiles of two fresh and oven-cooked pepper cultivars, red hot Aleppo (Capsicum annuum L.) and red sweet pepper Capia (Capsicum annuum L.). Phenolic extracts of pepper samples have been, for the first time, qualitatively and quantitatively examined by liquid chromatography including tandem mass spectrometry (LC–MS/MS). Apart from the main objective, samples were also examined for their colour alteration regarding the oven cooking process. A total of 20 phenolic compounds were identified and quantified in the red pepper samples. The revealed results showed that the hot Aleppo pepper possessed a much higher phenolic content when compared to Capia peppers. In the Aleppo pepper samples, capsaicin, luteolin 6,8-di-C-hexoside, luteolin O-malonylpentosyldihexoside, luteolin 6-C-hexoside, dihydrocapsaicin, and kaempferol pentosyldihexoside were the most dominant phenolics, while luteolin O-(aposylmalonyl)glucoside, luteolin O-malonylpentosyldihexoside, kaempferol pentosylhexoside, and feruloyl hexoside were for the Capia samples. In the Aleppo samples, capsaicin and dihydrocapsaicin were compounds that significantly increased due to the cooking process. The cooking process not only positively affected the phenolic profile of pepper samples but also the colour, total phenolic content, and antioxidant activity. [ABSTRACT FROM AUTHOR]

Sweet pepper crops suffer major losses from anthracnose caused by Colletotrichum spp. In the present work we describe the combined effects of cultivation in the dry and rainy seasons, of nitrogen fertilization doses (0-450 Kg/ha), the use of organic (grass) and plastic soil mulches, as well as the application of a synthetic protectant fungicide (chlorothalonil) for disease control. Overall results indicate that choice of planting season is the most decisive factor for sweet pepper anthracnose management. Use of fungicide is a less decisive but still important factor, followed by choice of soil mulch substrate and nitrogen fertilization. The combined effects of all cultural practices were demonstrated: for instance, in the rainy season, fungicide alone was not as efficient as the combined use of fungicide and grass mulch. Conversely, in the dry season fungicide applications may be discarded, when organic soil mulch is adopted. The effects of the type of soil cover on the splash dispersal of Colletotrichum conidia are discussed. Management practices described here are of practical value for either organic or conventional growers. [ABSTRACT FROM AUTHOR]

Sweet pepper purees (red, yellow and green) were examined for FTIR (Fourier-transform infrared spectroscopy), chemical, bioactive, color and rheological parameters. FTIR technique was used to evaluate the functional groups. FTIR wave numbers are associated with the absorption bands that depicted the presence of several phytocompounds in the purees. Among the chemical parameters, water activity varied non-significantly whereas, total soluble sugars (TSS), sugars and pH increased after processing of the fruits into purees. The presence of bioactive compounds depends on the variety of sweet pepper. The red puree had significantly higher carotenoids, phenolics and antioxidant capacity followed by yellow and green pepper purees. The minimal change was observed in the color of purees during processing. The purees were subjected to different shear rate (1 to 50 s−1) to evaluate the effect on viscosity and shear stress that is desirable for its end use in different food products. All purees show the shear thinning behavior as shear rate increased. Results revealed that heat processing of sweet peppers didn't affect color, sugars, carotenoids, phenolics and antioxidant capacity to a greater extent. The finding will be helpful to manage seasonal bulk production efficiently and make them available as an ingredient in various food products. [ABSTRACT FROM AUTHOR]

Associating desirable agronomic characters of sweet peppers and resistance to bacterial spot (BS) has been challenging plant breeders, especially when seeking durable resistance. In this work, we select BS resistant progenies with desirable agronomic characteristics by mixed model. F2:3 plants derived from sixty F2 individuals from crosses between pure lines UENF 2285 (susceptible) × UENF 1381 (resistant) were phenotyped. For BS resistance assessment, 1320 seedlings were inoculated with Xanthomonas euvesicatoria in greenhouse. The progress of the disease on seedlings was evaluated by using a score scale, with values from one to five, for eleven consecutive days. With the values of the Area Under Disease Progress Curve (AUDPC), the components of variance were estimated, and the genetic values for resistance to bacterial spot predicted. Resistant seedlings were cultivated in the field for agronomic characters phenotyping. The average rank index was used to select promising offspring. The coefficient of additive genetic variation (12.97–32.57%) confirmed the existence of genetic variability in the population. The progeny-mean heritability was of high magnitude (80–97%), and narrow sense heritability had average magnitude (17–65%), which indicates desirable gains with the selection of individual plants. The accuracy of the selection was above 80% for all studied traits. The predicted genetic value for AUDPC was negative and the genetic gain was null; in contrast, for the IP variable and morphoagronomic characters, the predicted genetic gain was high. Thirty-three percent of promising segregation lines were selected, which should originate new pure line type sweet pepper cultivars resistant to BS. [ABSTRACT FROM AUTHOR]

Sweet pepper (Capsicum annuum L.) is a high value crop and one of the most widely grown vegetables belonging to the Solanaceae family. In addition to commercial varieties and F1 hybrids, a multitude of landraces are grown, whose genetic combination is the result of hundreds of years of random, environmental, and farmer selection. High genetic diversity exists in the landrace gene pool which however has scarcely been studied, thus bounding their cultivation. We re-sequenced four pepper inbred lines, within as many Italian landraces, which representative of as many fruit types: big sized blocky with sunken apex ('Quadrato') and protruding apex or heart shaped ('Cuneo'), elongated ('Corno') and smaller sized sub-spherical ('Tumaticot'). Each genomic sequence was obtained through Illumina platform at coverage ranging from 39 to 44×, and reconstructed at a chromosome scale. About 35.5k genes were predicted in each inbred line, of which 22,017 were shared among them and the reference genome (accession 'CM334'). Distinctive variations in miRNAs, resistance gene analogues (RGAs) and susceptibility genes (S-genes) were detected. A detailed survey of the SNP/Indels occurring in genes affecting fruit size, shape and quality identified the highest frequencies of variation in regulatory regions. Many structural variations were identified as presence/absence variations (PAVs), notably in resistance gene analogues (RGAs) and in the capsanthin/capsorubin synthase (CCS) gene. The large allelic diversity observed in the four inbred lines suggests their potential use as a pre-breeding resource and represents a one-stop resource for C. annuum genomics and a key tool for dissecting the path from sequence variation to phenotype. [ABSTRACT FROM AUTHOR]

Two genotypes of sweet pepper were studied regarding their profile of quality indexes related to yield, taste and healthy components. The peppers were grown with three different types of cultivation, one conventional (CONV) and two organic (ORG), in three harvest years, 2015, 2016, and 2017. The two genotypes belong to the typology "red long horn", comparing a local cultivar selected for organic production (RTV), against a commercial F1 hybrid (Alceste F1). The main quality indexes of sweet pepper were measured, considering yield, tastants such as sugars, organic acids, volatiles and phytochemicals such as ascorbic acid, carotenoids, and tocopherols. Moreover, the Folin–Ciocalteu and DPPH assays were performed to assess the total polyphenols content and the antioxidant capacity. The results indicated that the 3 years of harvest were different, with the summer of 2016 more rainy and less warm than others, and most significant differences among the samples were due to this factor. The data collection indicates that ORG fruits had significant higher agronomic yield and sugar content, while higher content of ascorbic acid, yellow carotenoids, and Folin–Ciocalteu index was found in 2016 with respect to 2015 and 2017, in accordance with the meteorological variations. Moreover, in 2016, some volatiles showed strong depletions in ORG vs CONV samples. In some cases, considerable differences between the genotypes were observed, due to the different adaptability to ORG conditions for RTV and to CONV conditions for Alceste F1. A high content of free sugars and ascorbic acid was found in RTV ORG, while high content of organic acids, carotenoids, and 2-methoxy-3-isobutyl pirazine was observed in Alceste F1 ORG. [ABSTRACT FROM AUTHOR]

Sweet pepper is an important vegetable crop in Egypt. It is cultivated for local consumption and exportation. The crop is attacked by a large number of pest species such as Western flower thrips, Frankliniella occidentalis (Pergande), whitefly, Bemisia tabaci (Genn.), the two-spotted spider mite, Tetranychu surticae Koch, and the beet armyworm, Spodoptera exigua (Hubner). The present study was conducted on the sweet pepper cultivated in greenhouses, during the winter plantation 2016/17 in a commercial farm located at Berkash district, Giza Governorate, Egypt. Three control programs were practiced: the first used biological control agents (BC), the predators, Orius albidipennis (Reuter), Macrolophus caliginosus (Wagner), Chrysoperla carnea (Steph.), and the egg parasitoid, Trichogramma euproctidis (Girault); the second was sprayed by the recommended chemical control program of the farm (CC); and the third was untreated as a control. Obtained results revealed that the BC program was the most significant one for controlling the complex of sweet pepper pests. Also, applying the BC program resulted to a high yield of sweet pepper production (35.06% increasing than the control). [ABSTRACT FROM AUTHOR]

Salicylhydroxamic acid (SHAM) is used in studies of plant respiratory metabolism as a specific inhibitor of alternative cyanide-resistant oxidase (AOX). The sensitivity of respiration in intact plant tissues to SHAM provides indirect evidence for electron transport through the AOX-mediated pathway (AOP) in the respiratory electron transport chain. In this study, chilling-sensitive plants (cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.), and sweet pepper (Capsicum annuum L.)) were exposed daily to short-term drops of temperature (to 12, 8, 4, and 1°С) by the end of night periods, and the effects of DROP treatments on SHAM-resistant and SHAM-sensitive respiration of leaves were examined. When leaf respiration in cucumber and tomato plants was measured at optimum temperature (25°C), it showed an increase after the DROP treatments; this phenomenon was caused by the activation of SHAM-sensitive respiration ascribed mainly to AOP activity. At low measurement temperature (15°C), the DROP treatments stimulated total respiration and SHAM-resistant respiration of cucumber leaves, which indicates the activation of electron flow through the cytochrome oxidase pathway (COP). Remarkably, the COP activity increased with the severity of DROP treatment. At high temperature (35°C), the respiration of cucumber leaves became less sensitive to SHAM, whereas SHAM-resistant respiration increased with the severity of DROP treatments. The contribution of the SHAM-sensitive component to the total leaf respiration in cucumber increased with the temperature during measurements. Upon changes in temperature, the SHAM-sensitive respiration in cucumber exhibited larger variations than the SHAM-resistant component, which implies a significant contribution of COP to the respiratory chilling tolerance. Our data suggest that although AOP pathway respiration plays an important role in respiratory activity of chilling-sensitive plants, COP pathway is the main mechanism for maintaining the respiration during low-temperature treatments. [ABSTRACT FROM AUTHOR]

In June 2017, sweet pepper plants showing chlorosis in leaves and fruits were observed in Susaki City, Kochi Prefecture, Japan. We had named the disease pepper chlorosis (Tairyoku-byo). A phytoplasma was observed by electron microscopy and identified as 'Candidatus Phytoplasma solani', based on homology searches and molecular phylogeny using nucleotide sequences of 16S rDNA. To our knowledge, this is the first report showing the occurrence of 'Ca. P. solani' in Japan. [ABSTRACT FROM AUTHOR]

Water scarcity is seriously affecting agricultural production, especially in arid and semi-arid areas. Therefore, there is increasing interest in improving water productivity in agriculture. This research aims to study the effects of deficit irrigation on the productive response of sweet pepper plants. Nine deficit irrigation strategies were assayed during two seasons (2017 and 2018) in a randomised complete block design with three replicates. These irrigation strategies consisted of applying 100%, 75% and 50% of the irrigation water requirement (IWR) during the entire growing period (continued deficit irrigation) or applying 75% or 50% of the IWR during one of the following stages (regulated deficit irrigation): vegetative growth, fruit setting, and harvesting. Pepper plants cultivated under deficit irrigation reduced fruit biomass and indicators of plant water status. Applying water deficits during the vegetative growth and fruit-setting stages had minimal effects on the marketable yield but with minimal water savings. Irrigating pepper plants with 75% or 50% of the IWR during the entire crop cycle or with 50% of the IWR during harvesting resulted in a high incidence of fruits affected by blossom end rot, which in turn, led to a drastic reduction of the marketable yield in relation to fully irrigated plants (− 36%, − 55% and − 44%, respectively). These strategies also recorded the highest soluble solid and phenolic contents. Reducing the water applied to 75% of the IWR at harvesting led to a yield reduction (− 19%) but with important water savings (21%) and acceptable levels of soluble fruit solids and phenolic compounds. [ABSTRACT FROM AUTHOR]

Optical sensors are a promising approach for assessing nitrogen (N) status of vegetable crops. However, their potential may be undermined if time of day influences measurements. This study evaluated the effects of time of day and N addition on measurements, made with two chlorophyll meters, SPAD-502 and MC-100, and two active canopy reflectance sensors, GreenSeeker handheld and Crop Circle ACS-470. Three treatments (N1, deficient, N2, conventional, and N3, excessive N application) of N concentration in the nutrient solution were applied by fertigation throughout a sweet pepper crop grown in soil in a greenhouse. Time of day of 12:00 and 15:00 h had an effect on measurements made with the SPAD-502, but only in the N1 treatment, suggesting that the effects of time of day were related to crop N status. This effect was slight, being 1.7 ± 0.02 SPAD units lower at 12:00 and 15:00 h compared to at 9:00 h (relative decrease of 3.6%). For the MC-100, a slight increase in Chlorophyll Content Index (CCI) values of 3.3 ± 0.1 units (relative increase of 6.3%) was observed at 15:00 and 18:00 h, relative to CCI values at 9:00 h, regardless of N treatment. The time of day effect on chlorophyll meters appears to be negligible in relation to the wide range of values measured in greenhouse-grown sweet pepper. Normalized Difference Vegetation Index, measured both with the GreenSeeker and Crop Circle, and Green Normalized Difference Vegetation Index, measured with the Crop Circle, were not affected by time of day in any of the N treatments, showing that these sensors and indices can be used with confidence at any time of the day. [ABSTRACT FROM AUTHOR]

The Bemisia tabaci whitefly was previously considered a single, highly polyphagous species, but is now accepted as a group of cryptic biological species. We investigated the host plant relations of two sister species, the "Mediterranean" (MED) composed of the Q1 and Q2 mitochondrial groups and the "ASL" species (formerly considered a MED group), to discover whether polyphagy was related to the global pest status. We compared their performance by measuring the oviposition rate, survival, fecundity and proportion of female offspring on 13 host plants from nine families. In addition, oviposition preference was compared among leaves of different ages. Significant (P < 0.05) differences were found between populations in all parameters, particularly in adult survival and fecundity. Females preferred strongly to oviposit on the oldest true leaf on tobacco and tomato and on young leaves of sweet potato and pepper. The greatest differences in fecundity occurred on bean, okra, squash, pepper and tobacco. Hosts favourable for all four populations were cotton and sweet potato; no offspring were produced on cassava, chard or tomato. Host ranges of Q1 populations from Europe and sub-Saharan Africa differed despite their close genetic relatedness at the mitogenome level. Discrepancies between the parental and offspring fitness were observed. Our findings show that (1) the species have differing but overlapping host plant ranges and (2) the Q1 is the most polyphagous and can utilise tobacco, which predisposes it to evolving resistance to neonicotinoids. Our findings contribute to the understanding of ecology of this pest species complex and aid the development of efficient pest control strategies. [ABSTRACT FROM AUTHOR]

Production of doubled haploid (DH) plants is an efficient tool in genetic and plant breeding programs; however, sweet pepper (Capsicum annuum L.) is recalcitrant to microspore embryogenesis and DH production. Trying to break the barrier of DH production, three independent experiments were conducted on microspore embryogenesis of sweet pepper. In the first experiment, the effect of cold (4 °C) and heat (32 °C) pretreatments were investigated on microspore embryogenesis of three genotypes of sweet pepper including "Inspiration F1," "Maratus F1," and "Magno F1" cultivars in a factorial design with three replications. Heat shock (32 °C for 7 days), applied to mannitol-starved anthers of "Inspiration F1," showed higher multinuclear microspore percent, number of multicellular structures, total embryos, cotyledonary embryos, and regenerants. In the second experiment, the effect of different concentrations of putrescine (0, 0.5, 1, 2, and 5 mg l−1) was evaluated on microspore embryogenesis of the three aforementioned cultivars of sweet pepper. The highest mean number of multicellular structures, cotyledonary embryos, and regenerants were achieved by applying 0.5-1 mg l−1 putrescine during the mannitol starvation and heat shock (32 °C) treatments of isolated microspore culture of "Inspiration F1" cultivar. Significant decrease in microspore embryogenesis efficiency was observed when high levels of putrescine (2 and 5 mg l−1) were used. Microspore embryogenesis was prevented completely at 5.0 mg l−1 putrescine. In the third experiment, the effect of different concentrations of ascorbic acid (0, 20, 50, 100, and 200 mg l−1) was investigated and the results showed that the application of ascorbic acid (20 and 50 mg l−1) during mannitol starvation and heat shock treatment (32 °C) caused remarkable improvement in the number of produced cotyledonary embryos and their regeneration ability compared to control treatment. However, the application of higher levels of ascorbic acid (100 and 200 mg l−1) inhibited microspore cell divisions and embryogenesis. In conclusion, the results indicated that both putrescine and ascorbic acid have significant effect on microspore embryogenesis efficiency of sweet pepper when they are used in appropriate concentrations. [ABSTRACT FROM AUTHOR]

Plants possess various inducible defences that result in synthesis of specialized metabolites in response to herbivory, which can interfere with the performance of herbivores of the same and other species. Much less is known of the effects of plant feeding by omnivores. We found that previous feeding of the omnivorous predator Macrolophus pygmaeus on sweet pepper plants significantly reduced reproduction of the two-spotted spider mite Tetranychus urticae and western flower thrips Frankliniella occidentalis on the same plants, also on leaves that had not been exposed to the omnivore. In contrast, no effect was found on the reproduction of the green peach aphid Myzus persicae. Juvenile survival and developmental time of T. urticae and M. persicae, and larval survival of F. occidentalis were not affected by plant feeding by M. pygmaeus. Larvae of F. occidentalis feeding on leaves previously exposed to M. pygmaeus required longer to develop into adults. Defence-related plant hormones were produced locally and systemically after exposure to M. pygmaeus. The concentrations of 12-oxo-phytodienoic acid and jasmonic acid-isoleucine in the attacked leaves were significantly higher than in the corresponding leaves on the uninfested plants, and jasmonic acid concentrations showed the same trend, suggesting that jasmonic-acid-related defence pathways were activated. In contrast, similar concentrations of salicylic acid were found in the attacked leaves of M. pygmaeus-infested plants and uninfested plants. Our results show that plant feeding by omnivorous predators decreases the performance of herbivores, suggesting that it induces plant defences. [ABSTRACT FROM AUTHOR]

In the present study sweet pepper plants, Capsicum annuum, were planted in greenhouse and open field conditions to test the effect of the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis on phytophagous and predatory arthropod populations. Furthermore, we tested the hypothesis that AMF may increase the crop yield (number of fruits and their weight) and activity level of polyphenol oxidase (PPO) and peroxidase (POD), enzymes that seemingly decrease infestation by arthropod pests. The most abundant arthropod species found were the peach-potato aphid, Myzus persicae, western flower thrips, Frankliniella occidentalis, and the seven-spot ladybird, Coccinella septempunctata. Sweet pepper mutualism with AMF significantly reduced colonization by the peach-potato aphid under greenhouse conditions. Aphid density increased, however, on two of four pepper varieties tested under open field conditions. The density of ladybird predators did not appear directly influenced by AMF under greenhouse conditions, whereas a significantly higher predator density was found on three out of four pepper plant varieties with fungal mutualism tested under field conditions. Crop yield was significantly higher on plants with AMF mutualism under greenhouse conditions, but no clear effects were detected under field conditions. Both PPO and POD activity increased significantly and remained higher than controls until day 14 of the experiment under mutualism with AMF, although only in the greenhouse. The results suggest that under greenhouse conditions, pepper plant mutualism with AMF can increase pepper yield by reducing the numbers of the key pest, peach-potato aphid. [ABSTRACT FROM AUTHOR]

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We investigated B tolerance in sweet pepper plants ( Capsicum annuun L.) under an elevated CO concentration, combined with the application of calcium as a nutrient management amelioration technique. The data show that high B affected the roots more than the aerial parts, since there was an increase in the shoot/root ratio, when plants were grown with high B levels; however, the impact was lessened when the plants were grown at elevated CO, since the root FW reduction caused by excess B was less marked at the high CO concentration (30.9% less). Additionally, the high B concentration affected the membrane permeability of roots, which increased from 39 to 54% at ambient CO concentration, and from 38 to 51% at elevated CO concentration, producing a cation imbalance in plants, which was differentially affected by the CO supply. The Ca surplus in the nutrient solution reduced the nutritional imbalance in sweet pepper plants produced by the high B concentration, at both CO concentrations. The medium B concentration treatment (toxic according to the literature) did not result in any toxic effect. Hence, there is a need to review the literature on critical and toxic B levels taking into account increases in atmospheric CO. [ABSTRACT FROM AUTHOR]

Sweet pepper plants were used as a host for rearing the green peach aphid, Myzus persicae (Sulz.) and the parasitoid, Aphidius matricariae (Hal.) (Hymenoptera: Aphidiidae) on aphid species. Successful cold storage of parasitoid pupae (inside the mummies) at 4.5+0.3°C of the different acclimation periods of 6, 12, 18, 24 and 36 hours at 8+1°C were achieved for at least 2 weeks, with high emergence and survival percentages and little effects on longevity. Adults' emergence, survival and longevity from the mummies, stored for 3 weeks, were affected but to a lesser degree. The process of cold storage failed without acclimatization. Despite some reduction in fecundity at the treatments of 2 and 3 weeks cold storage, this level was compatible with the objective of cold storage. [ABSTRACT FROM AUTHOR]

Bacterial wilt of sweet pepper, caused by Ralstonia solanacearum (Rs) race 1, is a limiting disease in northern and northeastern Brazil. The present study evaluated the effect of silicon (Si) on the disease in the sweet pepper cv. Enterprise, which was grown in a substrate containing 0.00, 0.25, 0.50, 1.50, or 3.00 g SiO2 kg-1 and was subsequently transplanted into soil infested with Rs CGM-8. The following variables were evaluated: latency period (LP50); incidence; bacterial wilt index (BWI); area under the disease progress curve (AUDPC); biomass; accumulation of Ca+2, Mg+2, and Si; total protein and enzymatic activity; chemical characteristics of the substrate; and in vitro bacterial growth. A dose of 2.95 g Si kg-1 substrate increased the LP50 (33.6%) and reduced the BWI (98%) and AUDPC (93.7%); this treatment also increased Ca+2 levels in the shoots and reduced Mg+2 levels in the shoots and the roots. Supplementation with various doses of Si yielded maximum increases in the shoot fresh biomass (121.8%), the root fresh biomass (83.6%), and the shoot dry biomass (84.9%); increased the concentrations of total protein, catalase, ascorbate peroxidase, and chitinase; caused the accumulation of Si in the shoots and substrate; increased the pH, Na+, and K+; and decreased P in the substrate. The putative mechanisms of action of Si included a direct effect on colonization of the pathogen, an indirect effect on the plant development, increased Ca+2 absorption, and signaled for the production of plant defence enzymes. Therefore, the production of sweet pepper seedlings in a substrate containing calcium silicate (2.95 g SiO2 kg-1) could be utilized as an alternative cultivation practice for the management of bacterial wilt disease. More research is needed to elucidate the exact mechanisms of silicon and its effects on latent infections and on bacterial cells and population. [ABSTRACT FROM AUTHOR]