Sweet Pepper Research Articles

Integrating Proteomics and Metabolomics Approaches to Elucidate the Mechanism of Responses to Combined Stress in the Bell Pepper (Capsicum annuum).

Bell pepper plants are sensitive to environmental changes and are significantly affected by abiotic factors such as UV-B radiation and cold, which reduce their yield and production. Various approaches, including omics data integration, have been employed to understand the mechanisms by which this crop copes with abiotic stress. This study aimed to find metabolic changes in bell pepper stems caused by UV-B radiation and cold by integrating omic data. Proteome and metabolome profiles were generated using liquid chromatography coupled with mass spectrometry, and data integration was performed in the plant metabolic pathway database. The combined stress of UV-B and cold induced the accumulation of proteins related to photosynthesis, mitochondrial electron transport, and a response to a stimulus. Further, the production of flavonoids and their glycosides, as well as affecting carbon metabolism, tetrapyrrole, and scopolamine pathways, were identified. We have made the first metabolic regulatory network map showing how bell pepper stems respond to cold and UV-B stress. We did this by looking at changes in proteins and metabolites that help with respiration, photosynthesis, and the buildup of photoprotective and antioxidant compounds.

Growth response and changes of soil chemical properties with application of vermichar in bell pepper production

Growth response and changes of soil chemical properties with application of vermichar in bell pepper production

Coating based on gelatin and propolis for the control of anthracnose in postharvest of bell pepper

Bell pepper (Capsicum annuum L.) is one of the most produced fruits in Brazil, however phytosanitary problems are still an obstacle to productivity. Anthracnose is one of the most aggressive diseases in postharvest. Seeking products of natural origin, the aim of this study was to evaluate ethanolic extracts of brown propolis (BP) and green propolis (GP) and their homeopathic preparations against the pathogen Colletotrichum scovillei. Additionally, the products were tested for the control of anthracnose, and their effects on physicochemical characteristics were assessed. GP extract inhibited completely the mycelial growth at 2.5 mg mL−1 and the spore germination at 5.0 mg mL−1, while the BP extract inhibited 100% the mycelial growth and 50% the spore germination at 5.0 mg mL−1. The homeopathic preparations from propolis and C. annuum (30 CH dynamizations) reduced the spore germination around 50%. When bell peppers inoculated with C. scovillei were immersed only in propolis extracts or homeopathic preparations, there was no effect on disease control. On the other hand, coating with these products combined with 10% gelatin reduced the disease incidence by around 50%. Bell peppers coated with propolis (ethanolic extract or homeopathic preprations) and gelatin showed 44% lower weight loss, 56% higher retention of titratable acidity, and 27% lower vitamin C content, indicative of a delay in the maturation process. This is the first report showing the potential of a homeopathic preparation of propolis combined with gelatin to control a post-harvest disease.

First Report of Xanthomonas perforans Causing Bacterial Spot of Pepper (Capsicum annuum) in North Carolina.

North Carolina (NC) is the fifth largest producer of bell pepper (Capsicum annuum) in the US with an estimated 2,400 acres in production (NASS-USDA, 2022). A survey of bacterial diseases of peppers was initiated in 2020 after numerous bacterial spot outbreaks were reported in NC. Bacterial spot is caused by a complex of four Xanthomonads: X. euvesicatoria, X. vesicatoria, X. perforans, and X. hortorum pv. gardneri (Larrahondo-Rodríguez et al., 2022). If not preemptively managed, bacterial spot can cause up to 40% yield loss (Kousik and Ritchie, 1998). During the 2020 and 2021 growing seasons, 103 yellow mucoid colonies were isolated from plants representing 51 pepper cultivars symptomatic of bacterial spot, i.e., water-soaked leaf lesions that become necrotic spots on leaves and fruits across 22 commercial fields in NC following published methods (Klein-Gordon et al., 2021). All colonies were characterized to species using the qPCR species-specific primers and probes described by Strayer et al. 2016. Of the 103 colonies, 12 isolates tested positive for X. perforans. To confirm qPCR results, a Multi-Locus Sequence Analysis (MLSA) was run using fusA, gapA, gltA, gyrB, and lacF following previously described methods (Almeida et al., 2010) on three representative isolates: AHX61, collected in September 2020 from a field with 20% disease severity in Wake County on cv. Canary Bell; AHX261, collected in July 2021 from a field with 50% disease severity in Sampson County on Jalapeño; and AHX426, collected in August 2021 from a field with 50% disease severity in Dublin County on Jalapeño. All gene sequences were deposited to NCBI (GenBank Accessions: OQ799538-OQ799552) and compared to those from X. euvesicatoria, X. hortorum pv. gardneri, X. perforans, and X. vesicatoria type strains (Almeida et al., 2010). The MLSA showed AHX61, AHX261, and AHX426 cluster with X. perforans ICMP16690T, sharing 99-100% nucleotide similarity. Koch's postulates were performed with the three strains, Xp1484T [ X. perforans type strain, (Wilson 1987)], and water as a negative control. Three 10-week-old bell pepper plants (cv. Early Cal Wonder) were dip-inoculated in 600 mL of a bacterial suspension at an OD600 of 0.3 (~5x108 CFU/mL) and 0.04% Silwet L-77 per strain or water. All 18 plants were individually incubated in a plastic bag for 48 h post-inoculation at 28°C, 80% relative humidity, and 14 h:10 h light-dark cycle in a growth chamber, after which plastic bags were removed. Water-soaking and necrotic spots characteristic of bacterial spot were first observed at six days post-inoculation (dpi). At 14 dpi, symptomatic leaves were removed from treated plants to attempt pathogen re-isolation. Yellow mucoid colonies similar in morphology to those originally inoculated were recovered from all plants and confirmed to be X. perforans through sequencing; no isolates were recovered from water-treated plants. To our knowledge, this is the first time X. perforans is isolated in commercial bell pepper and specialty pepper fields in the state. This is an indication that the Xanthomonas population on peppers in the state is more diverse than previously reported and that pathogen populations will require monitoring for possible species shifts for this crop in NC.

Characterization of pectolytic bacteria causing soft rot on sugar beet in the west of Iran

AbstractBacterial soft rots are amongst the most economically important diseases that cause significant yield losses in various crops. A clear identification of the causal agents is required to develop management strategies. In 2022 and 2023, after the widespread occurrence of soft rot disease in sugar beet fields in the Firuzan region, Hamedan Province, Iran, the current study was conducted to identify and characterize the causal agents. A total of 38 bacterial isolates were obtained from sugar beet plants with soft rot symptoms and subjected to biochemical and phenotypical characterization and pathogenicity tests on healthy slices from potato tubers and sugar beet taproots. Twelve isolates from this study along with the type strain Pectobacterium carotovorum ICMP 5702 were selected for subsequent screening by BOX‐PCR. Six isolates were chosen for sequencing the 16SrRNA gene and phylogenetic analysis. In BLAST analyses, the pathogenic isolates S2, S9, S22, S11, S23 and 111 showed the highest similarity values (≥99%) with the reference sequences of Raoultella terrigena, Klebsiella michiganensis, Erwinia (Winslowiella) iniecta, Pantoea agglomerans and P. carotovorum, respectively. These isolates induced soft rot and maceration on plant materials from five species (bell pepper fruits, garlic cloves and slices from sugar beet taproot, potato tubers and carrot roots) 72 h after inoculation. In the greenhouse experiment, they caused soft rot symptoms in the taproots of 2‐month‐old sugar beet plants 3 weeks after inoculation. These soft rot agents had Gram‐negative, catalase‐positive and oxidase‐negative reactions, grew under both aerobic and anaerobic conditions, tolerated and grew at 37°C and 5% NaCl. In general, the results of this research showed that in addition to Pectobacterium, four other genera from the order Enterobacterales including Erwinia, Pantoea, Klebsiella and Raoultella, are amongst the causes of soft rot in sugar beet in Firuzan region of Hamedan.

The sky is not the limit: Successful foliar application of Steinernema spp. entomopathogenic nematodes to control Lepidopteran caterpillars

Entomopathogenic nematodes (EPNs) are ubiquitous soil-thriving organisms that use chemical cues to seek and infect soil-dwelling arthropods, yielding various levels of biological control. Going beyond soil application, scientists and practitioners started exploring the option of applying EPNs onto the foliage of crops in attempts to manage leaf-dwelling insect pests as well. Despite some success, particularly with protective formulations, it remains uncertain whether EPNs could indeed survive the phyllospheric environment, and successfully control foliar insect pests. In this context, we tested the potential of commercially produced Steinernema feltiae and S. carpocapsae, two of the most commonly used EPNs in the field of biological control, in controlling Lepidopteran foliar pests of economic importance, i.e. Tuta absoluta and Spodoptera spp. caterpillars as models. We first tested the survival and efficacy of both EPN species against the Lepidopteran caterpillars when applied onto tomato, sweet pepper and lettuce leaves, under controlled conditions and in commercial greenhouse conditions, respectively. Subsequently, we explored the behavioural responses of the EPNs to environmental cues typically encountered in the phyllosphere, and analysed plant volatile organic compounds (VOCs). Our results show that both S. feltiae and S. carpocapsae successfully survived and infected the foliar caterpillars, reaching similar level of control to a standard chemical pesticide in commercial practices. Remarkably, both EPN species survived and remained effective up to four days in the phyllosphere, and needed only a few hours to successfully penetrate the caterpillars. Interestingly, S. feltiae was attracted to VOCs from tomato plants, and tended to prefer those from caterpillar-induced plants, suggesting that the nematodes may actively forage toward its host, although it has never been exposed to leaf-borne volatiles during its evolution. The present study shows the high potential of steinernematids in managing major foliar pests in greenhouses and in becoming a key player in foliar biological control. In particular, the discovery that EPNs use foliar VOCs to locate caterpillar hosts opens up new opportunities in terms of application techniques and affordable effective doses.

Intervention of Bacterial Leaf Spot of Bell Pepper through Neem Mediated Copper and Zinc Hybrid Nanoparticles

Intervention of Bacterial Leaf Spot of Bell Pepper through Neem Mediated Copper and Zinc Hybrid Nanoparticles

Hybrid passive cooling and heating system for Mediterranean greenhouses. Microclimate and sweet pepper crop response

The microclimate of low-tech, unheated greenhouses in Mediterranean areas, associated with the local outdoor climate, is often outside the optimal range for most horticultural crops during both the warm and cold growing season. The use of a new hybrid system of passive cooling (evaporative screens) and heating (water-filled sleeves), in combination with an internal movable shading/thermal screen, was evaluated on a representative summer transplanted sweet pepper crop grown in perlite growing bags. The experiment was carried out in two identical greenhouses at the IFAPA La Mojonera research center in Almeria (SE Spain): one greenhouse with the hybrid passive system of cooling and heating, in combination with a shading/thermal screen, and another (reference greenhouse) using common local greenhouse climate management practices. Evaporative screens, in combination with a movable shading screen, improved the greenhouse climate, in particular the air vapour pressure deficit, and increased the leaf area index in the early stages of the crop, which, in turn, increased the early production of leaf and shoot dry matter and marketable fruit, compared to the reference greenhouse crop. In addition, the combined use of water-filled sleeves and thermal screen during the cold growth period increased greenhouse air temperatures, especially at night, and substrate temperatures. Overall, by improving the greenhouse microclimate during the warm and cold growth periods, the hybrid passive cooling/heating system, in combination with the shading/thermal screen, increased the marketable yield of a summer transplanted sweet pepper crop by 25 %, reduced the irrigation water supply by 8 %, and improved the irrigation water use efficiency by 20 % (including the potential water used to humidify the evaporative screens).

Productivity, Quality and Economics of Sweet Pepper (Capsicum annum) Cultivars under Modified Net House Conditions in Arid Regions

Productivity, Quality and Economics of Sweet Pepper (Capsicum annum) Cultivars under Modified Net House Conditions in Arid Regions

Impact of Deficit Irrigation on Bell Pepper (Capsicum annuum var. Grossum) Cultivation

The purpose of this study is to determine the effect of deficit irrigation application on the growth of bell pepper plants and to assess the efficiency of irrigation water application for bell pepper plants. The design used in this research is a Completely Randomized Design with 4 levels of deficit irrigation treatments and six replications. The procedures involved in this study include analysis of soil moisture to determine field capacity and permanent wilting point, treatment conditioning, planting, plant maintenance, observations, and finally, harvesting. The data obtained were tested for homogeneity of variances using the F-test, and if there were differences among treatments, further analysis was conducted using the Least Significant Difference test at the 5% level. The results of the data analysis are presented in tables, graphs, and diagrams. Deficit irrigation treatments significantly affected the plant height and leaf number parameters. The plant response to irrigation was limited under deficit irrigation based on total fruit weight, where bell pepper plants produced the best fruit under the 80% deficit irrigation treatment, with an average total fruit weight of 242.17 grams. Meanwhile, in the ID4 treatment, the plant results were less favorable due to stress. The response of the results to water (Ky) indicates that the Ky value (Ky <1) for bell pepper plants in the ID2, ID3, and ID4 treatments shows values less than 1, meaning that these treatments are tolerant to water stress. Keywords: Bell Pepper, Deficit irrigation, Irrigation, Yield response

Olfactory responses of the blister beetle Epicauta atomaria, a polyphagous crop pest, to host, non‐host, and conspecific odors

AbstractThe blister beetle Epicauta atomaria (Germar) (Coleoptera: Meloidae) is a phytophagous pest of various agricultural crops, especially in Amaranthaceae, Solanaceae, and Fabaceae. Currently, this insect is managed through the spraying of synthetic insecticides that cause serious human health and environmental damage. To reduce the use of synthetic insecticides, the integrated pest management (IPM) programs for other crop pests rely on the use of semiochemical compounds, such as pheromones, kairomones, and allomones, to manipulate the insects' behavior to prevent crop damage. However, studies on semiochemical compounds related to E. atomaria have never been carried out. For this reason, the aim of this study was to explore the chemical communication of E. atomaria. This includes the existence of (i) a sex and/or an aggregation pheromone, (ii) attractant volatile kairomones from host plants, and (iii) repellent volatile allomones from non‐host plants. Tests were carried out using olfactometers and an experimental arena. First, olfactometer tests failed to show the existence of volatile sex and/or aggregation pheromones of these insects. Second, olfactometer and experimental arena tests failed to demonstrate attraction of E. atomaria via volatile kairomonal compounds from host plants (chard, bell pepper, and cock's‐eggs). However, olfactometer tests showed that non‐host plants of E. atomaria (thyme and lavender) emit allomonal volatile compounds with repellent activity. This work represents a first step toward the elucidation of the chemical ecology of E. atomaria and suggests that volatiles from non‐host plants help shape the host preferences of these insects. Those volatiles could be used as a “push” component in a “push–pull” strategy against this pest.

SOURCE MATERIAL FOR HETEROSIS SELECTION OF SWEET PEPPER

The purpose of the research is to identify promising genotypes of sweet pepper source material based on the main economically valuable traits for further use in heterosis selection. Methods: Field, laboratory, measurement-weight, statistical. Results: The study highlighted that the best samples of source material for breeding sweet pepper for earliness were the genotypes: Iga, L. 183/331, Polet, Rewia, which reach technical maturity in 99–103 days. The most large-fruited samples compared to the standard variety Snihur (12; 6 cm) were: Robertina (13; 7 cm), Veronika (15; 7 cm), Ania (19; 7 cm), Herakl (16; 7 cm), Lai lak bell (13; 7 cm), Fatima (16; 7 cm), Horticolas (17; 9 cm), Enei (13; 8 cm). It was found that the highest number of fruits per plant was in samples: Druzhok (11 pcs.); L. 183/331 (12 pcs.); L. 184/332 (16 pcs.); Kurtovskakapia (11 pcs.); Oda (11 pcs.); Tsyhanskyi baron (12 pcs.); King kong (11 pcs.); Chornyi kin (11 pcs.). The samples highlighted for "average commercial fruit weight" were: Ania (197 g); Herakl (174 g); Horticolas (246 g); Bel hoi (189 g); Enei (177 g); Tonenoelloy (186 g). The highest fruit productivity of sweet pepper was observed in the genotypes: Aivengo (1210 g/plant); Alexia (1205 g/plant); Druzhok (1326 g/plant); Ania (1482 g/plant); Anastasiia (1320 g/plant); Iga (1246 g/plant); Herakl (1436 g/plant); Horticolas (1331 g/plant); King kong (1256 g/plant). Conclusions: Thus, the conducted breeding research allowed identifying the main genotypes that combine several important quantitative traits – these are L. 183/331, L 184/332, Ania, Herakl, Horticolas, King kong.

Using Bromelain Application to Inhibit the Spread of the Tobacco Mosaic Virus and Promote Tissue Regeneration in Red Bell Pepper Plants

Using Bromelain Application to Inhibit the Spread of the Tobacco Mosaic Virus and Promote Tissue Regeneration in Red Bell Pepper Plants

Pesticide residues in food of plant origin commercialized in Brazil from 2010 to 2020 – An update from the two national monitoring programs

The objective of this study was to investigate the results of the two Brazilian national pesticide residue monitoring programs obtained from January 2010 to December 2020. A total of 35,321samples of 44 different food crops were analyzed, of which 55.3% tested positive for at least one compound, with pear, peach, strawberry and sweet pepper having over 90% of the analyzed samples containing residues. Approximately one-third of the positive samples had at least one irregularity, of which 86.7% due to the presence of non-authorized pesticides for the crop, 26.3% exceeding the maximum residue level, and 13.1% showing both irregularities. A total of 191 different compounds were detected, primarily organophosphorus (OP) (37.4% of positive samples, of which over 60% of cereal/flour, potatoes, and peanuts). Chlorpyrifos, acephate, pirimiphos-methyl, and methamidophos were the main OPs detected. Triazoles were present in 27.2% of the positive samples, mainly rice, and pyrethroids in 22.4% of the positive samples, mainly in popcorn. Dithiocarbamates were present in 19.7% of the positive samples, predominantly in apples, and 5.0% of the positive samples contained N-methyl carbamates, mainly in sweet peppers. Carbendazim was the most detected pesticide (30% of positive samples), mainly in papaya (18.2% of samples containing this pesticide). About 60% of positive samples contained multiple residues, primarily in sweet pepper, pear, strawberry, and orange (over 80% of positive samples). Compared to the previous decade (2001–2010), these results indicated increased percentages of positive, irregular and of samples containing multiple residues. Dithiocarbamates were no longer the most detected pesticide group, while carbendazim remained the most detected pesticide in both periods.

Interacting effects of phytohormones and fruit pruning on the morpho-physiological and biochemical attributes of bell pepper

Several factors, such as pruning and phytohormones, have demonstrated an influence on both the quantity and quality in the bell pepper. A factorial experiment using a completely randomized design was conducted on the Lumos yellow bell in a greenhouse. Treatments were the fruit pruning (0, 10, and 30%) and foliar application of phytohormones auxin (AUX) and gibberellic acid (GA3) at concentrations of 10 µM AUX, 10 µM GA3, 10 µM AUX + 10 µM GA3+, and 20 µM AUX + 10 µM GA3 along with controls. The plants were sprayed with phytohormones in four growth stages (1: flowering stage when 50% of the flowers were on the plant, 2: fruiting stage when 50% of the fruits were the size of peas, 3: fruit growth stage when 50% of the fruits had reached 50% of their growth, and 4: ripening stage when 50% of the fruits were at color break). The results of the present investigation showed that pruning rate of 30% yielded the highest flesh thickness and vitamin C content, decreased seed count and hastened fruit ripening. The use of GA3 along with AUX has been observed to augment diverse fruit quality characteristics. According to the results, the application of 10% pruning in combination with 20 µM AUX and 10 µM GA3 demonstrated the most significant levels of carotenoids, chlorophyll, and fruit length. The experimental group subjected to the combined treatment of 30% pruning and 10 µM AUX + 10 µM GA3 showed the most noteworthy levels of vitamin C, fruit weight, and fruit thickness. The groups that received the 10 µM GA3 and 20 µM AUX + 10 µM GA3 treatments exhibited the most favorable fruit flavor. According to the research results, the implementation of hormonal treatments 10 µM AUX and 10 µM AUX + 10 µM GA3 in combination with a 30% pruning strategy resulted in the most advantageous yield of bell peppers.

A fluorescence switch-off nanosensor for sensitive determination of the antiandrogen drug flutamide in pharmaceutical and environmental samples. Analytical method greenness, blueness, and whiteness assessment

A fast, practical, and non-hazardous switch-off fluorescent nanosensor for the non-fluorescent antiandrogen drug flutamide (FLU) was developed from nitrogen/sulfur co-doping of carbon quantum dots (N,S-CQDs). For the first time, the highly fluorescent N,S-CQDs were generated via one-pot microwave-assisted synthesis in only 3 min using facilely available precursors (sweet yellow pepper and thiourea). The sensor is characterized by a narrow particle size distribution, high doping efficiency (N, 42.05 % and S, 8.28 %), reproducibility, and high emission at 410 nm after excitation at 330 nm. FLU efficiently and quantitatively turned off the fluorescence of the prepared N,S-CQDs via a synergistic combination of static quenching and inner filter effect. The furnished nanosensor showed good linearity (r = 0.9999) for FLU analysis within concentrations ranged from 1.0 to 30.0 µg mL−1 with a detection limit of 0.293 µg mL−1 and quantitation limit of 0.886 µg mL−1. The selectivity of the probe was confirmed in the presence of co-administered drugs, possible co-existing materials, and various metal ions. The N,S-CQDs interestingly showed acceptable cytocompatibility and low toxicity, as revealed by the MTT assay. This feature bestows the N,S-CQDs a practicability as an environmental sensor. Thus, the proposed approach was implemented for FLU analysis in pharmaceutical tablets, tap water, and river water with good percentage recoveries (99.59 ± 1.28%, 99.49 ± 1.75%, and 101.21 ± 1.67%, respectively) and without interferences. Furthermore, the approach was positively assessed with respect to greenness, blueness, and whiteness. The high values of the analytical greenness score AGREE (0.78), the chiefly green ComplexGAPI pictogram, the Blue Applicability Grade Index BAGI (72.5), and the RGB12 (93.6) show the high greenness, blueness, and whiteness features of the method that confirm its minor environmental impact, excellent applicability, and sustainability, respectively.

Anti-Listeria efficacy of peroxyacetic acid in bacterial buffered solution and on bell peppers

This study aims to 1) evaluate the efficacy of peroxyacetic acid (PAA) to inactivate Listeria monocytogenes in 0.1 % buffered-peptone-water; and 2) evaluate the reduction and mitigation of cross-contamination on peppers. In study-1, aliquots of 1.0-ml PAA solutions (133, 265, and 448 ppm) were added to the first 6 wells of 8-strip-deep well microplates. Then, 0.1 ml of serially diluted nalidixic-acid-resistant (NaL) L. monocytogenes was added and mixed immediately with a multichannel pipette. After exposure for 0, 5, 15, 30, and up to 120-s, 1 ml of 2 × D/E neutralized solution was added to terminate the reaction followed by spread-plating onto tryptic soy agar +200 ppm NaL and incubated at 35 °C for 48 h. In study-2, 5 inoculated red peppers were triple-washed with 15 uninoculated green peppers with 0, 23, 53, and 96 ppm of PAA and analyzed using MPN-method. L. monocytogenes counts were <0.3 log10 CFU/ml after exposure to 133, 265, and 448 ppm of PAA for 120, 90 and 60 s, respectively and fit the Linear and Weibull Models. Applying 23–96 ppm of PAA reduced L. monocytogenes by 2.03–3.32 log10MPN/g and transferred cross-contaminated cell counts by 2.36–3.17 log10MPN/g, with no differences (P > 0.05) compared to the water only treatment. Results suggested that applying allowable concentrations (23–96 ppm) of PAA during triple-wash does not show promising anti-Listeria activity on peppers. Future studies are needed to determine the minimum concentrations of the PAA solution required to effectively reduce and mitigate microbial cross-contamination of Listeria monocytogenes on peppers.

Botanical Vegetables Recognition on Raspberry Pi Using Single Shot Detector (SSD)

Advancements in computer vision technologies have fueled research interest in automating object detection, particularly in agricultural contexts. Human eyes prone to error during the sortingprocess when differentiating the various types of botanical vegetablessuch as bell pepper (capsicum), chili, tomatoes, etc. Hence, the use an object detection method is believed could categorize this botanicalvegetables precisely, allowing farmers to optimize their operations and reduce labor expenses. This study exploresthe identification of various botanical vegetables types using a Raspberry Pi and the Single Shot Detector (SSD). The proposed approach involves curating an extensive botanical vegetables dataset with detailed annotationsto optimize training process.Implementing SSD on the Raspberry Pi capitalizes on its processing power and versatility. Our research demonstrates the system's effectiveness in detecting a wide range of botanical vegetables, including chili, capsicum, tomatoes, and vegetable leaf, achieving an average precisionof 89% across diverse environmental conditions. Computational efficiency analysis showcases its real-time vegetable detection capabilities, rendering it suitable for agricultural applications such as automated sorting, inventory management, and quality monitoring.

Eco-friendly management of fall armyworm: can host-plant intercropping drive to a sustainable IPM?

Although over 350 species of plants have been documented to host the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), its invasion in West Africa has been mainly on maize. This study investigated the factors that limit the host utilization and tested the effects of intercropping of Poaceae (maize, sorghum, rice and Proso millet), Solanaceae (tomato and sweet pepper), and Fabaceae (cowpea and soybean) plants on FAW severity. The laboratory larvae fed with those crops showed higher pupation rates for maize (33.6%) than sorghum (20%), rice (24.2%), Proso millet (17.6%), tomato (fruit = 5.3% and leaf = 6 .4%), sweet pepper (fruit = 1.3% and leaf = 1.6%). Only larvae fed with Poaceae plants reached the adult stage. Female ovipositional potentiality was higher with maize compared to other Poaceae plants. In the field experiments, FAW severities were recorded only on Poaceae plants. However, the severity of FAW was significantly reduced on the intercropped maize with other crops compared to monocultures of maize. Therefore, intercropping can be considered as an eco-friendly FAW-IPM program in West Africa.

Cultivar effect on proximal optical sensor measurements and estimation of leaf N content in muskmelon and sweet pepper

In intensive vegetable crops, there is a requirement for monitoring tools that assess crop nitrogen (N) status to reduce N use and the potential for nitrate (NO3-) leaching loss. Monitoring with proximal optical sensors can regularly provide information to vegetable growers to assist with optimal crop N management. Reference values for proximal optical sensor measurements that indicate crop N sufficiency or deficiency are increasingly available in the literature. Available values are species specific; however, their use may be problematic if proximal optical sensor measurements are affected by cultivar. Little is known on whether differences between cultivars, within a species, affect optical sensor measurements and their relationships with crop N status, particularly in vegetable crops. This study evaluated the effect of cultivar on a) measurements with the SPAD-502 chlorophyll meter, Normalized Difference Vegetation Index (NDVI) measured with the Crop Circle ACS 470 canopy reflectance sensor, and Nitrogen Balance Index (NBI-R) measured with the Multiplex fluorimeter, and b) the relationships of these measurements with leaf N content. The study was conducted with four cultivars of muskmelon (Tezac, Bosito, Magiar and Jacobo) and three of sweet pepper (Melchor, Machado and CLX PLRJ 731). In both muskmelon and sweet pepper, there were significant differences between cultivars in SPAD and in NBI-R. The range of differences between the cultivars was 2.2−9.7 and 0.6−2.8 SPAD units in muskmelon and sweet pepper, respectively, and 0−0.16 and 0.020.08 NBI-R units in muskmelon and sweet pepper, respectively. Significant differences between cultivars in the NDVI were only obtained in muskmelon; the range of differences between the four cultivars was 0.01–0.04 NDVI units. The relatively large cultivar effect with SPAD and NBI-R values with muskmelon may limit the use of reference values in this species. For avoiding cultivar effects in the two species evaluated, NDVI is preferrable to SPAD and NBI-R. In general, the slopes and intercepts of linear relationships between optical sensor measurements and leaf N content, for each cultivar of each species, were not significantly different to the slope and intercept of the relationship calculated with pooled data of all cultivars of each species. This indicated that the sensitivity of optical sensors to assess leaf N content was similar between cultivars of each species.