An epidemiological study was conducted in three processing tomato fields irrigated by center pivots (CP) in Goiás state, Brazil. These CPs, partially surrounded by dense eucalyptus trees, were adjacent to soybean fields heavily infested with the whitefly Bemisia tabaci MEAM-1. Given the potential for a high incidence of Golden Mosaic Disease (GMD) caused by the begomovirus tomato severe rugose virus (ToSRV), the study aimed to evaluate the incidence, spread, and potential sources of the virus.

Tomato is one of the most important and widely grown vegetables in the world. The aim is to review the key challenges on tomato production and marketing in Ethiopia. In Ethiopia, tomato production is concentrated in river, valleys and lakes, especially in Awash Valley and around Lake Ziway for favorable growing conditions, good access to market outlets and better infrastructure. Tomato production is commercially important for fresh fruit market and processing. Some of tomato varieties that have been in use by farmers are used for processing and for fresh marketing. However, several constraints caused inconsistent of tomato production and low yielding’s are; the shortages of improved varieties, inadequate transport, poor marketing system, poor cultural practices, unreliable rainfall, price fluctuation, product nature (perishability), post-harvest losses, pest and diseases. Lack of market linkages, post-harvest losses, low institutional support, lack inputs and transportation are the key challenges. Small-scale producers are struggling to gain market access, but due to listed challenges the farmers are not selling their produce in an organized system and not getting the right shares. Therefore, critical attentions in harvesting and postharvest operations are very important to reduce losses, to keep quality and market standards. Moreover, addressing both production and market-related challenges are essential to minimize the losses, to access quality goods and to ensure the right shares for producers, distributors, processors and traders.

Late blight caused by the oomycete Phytophthora infestans poses a severe threat to global tomato (Solanum lycopersicum L.) production. While genetic resistance forms the cornerstone of disease control, the mechanisms underlying cultivar-specific resistance, particularly their interactions with rhizosphere microbiomes, remain poorly understood. To elucidate the mechanisms of tomato cultivar resistance to late blight and screen out antagonistic microorganisms against P. infestans, we investigated the microbial compositions in the rhizospheres of tomato cultivars with different late blight-resistance levels under both natural and P. infestans-inoculated conditions. Considerable differences in soil microbial diversity and composition of rhizospheres were found between late blight-resistant and -susceptible tomato cultivars. Under natural conditions, the resistant tomato cultivar exhibited higher bacterial diversity and lower fungal diversity than that of the susceptible cultivar. Additionally, after P. infestans inoculation, both the resistant and susceptible cultivars showed enrichment of microorganisms with potential antagonistic effects in the rhizospheres. Among them, bacterial genera, such as Pseudomonas, Azospirillum, and Acidovorax, and fungal genera, including Phoma, Arthrobotrys, Pseudallescheria, and Pseudolabrys, were enriched in the rhizospheres of the late blight-resistant tomato cultivar. In contrast, bacterial genera, including Flavobacterium, Pseudolabrys, and Burkholderia-Caballeronia-Paraburkholderia, and the Trichoderma fungal genus were enriched in the rhizospheres of the late blight-susceptible tomato cultivar. Simultaneously, the enrichment of pathogenic microorganisms, such as Neocosmospora and Plectosphaerella, was also detected in the rhizospheres of the susceptible tomato cultivar. Moreover, no enrichment of pathogenic microorganisms occurred in the late blight-resistant tomato cultivar after P. infestans inoculation. These findings suggest that these traits serve as effective defense mechanisms against pathogen invasion in resistant tomato cultivar. Overall, this study provides a comprehensive analysis of the rhizosphere microbial community structures in late blight-resistant and -susceptible tomato cultivars under natural conditions and their response following pathogen inoculation. Additionally, potential antagonistic microorganisms against late blight were also identified. The findings offer valuable insights for effective late blight management in tomatoes and contribute to the development of sustainable agricultural practices.

Using <i>Bacillus</i> species as bioagents for environmentally sustainable and economically viable plant disease management is a viable strategy. Thus, it is important to promote their use in agriculture. In this study, two <i>Bacillus</i> species were isolated from the rhizosphere of tomato plants, while three fungal species were isolated from samples of tomato plants that were infected with damping-off disease. The <i>Bacillus</i> strains were tested in vitro for their antagonistic activity against fungal species using a dual culture technique. In a greenhouse experiment, the effectiveness of applying antagonistic bacteria with soilborne fungal disease on induced damping-off of tomato (cv. Super Strain B) plants, their physiological attributes, antioxidant enzymes, mineral content, and yield under greenhouse conditions during the 2022 and 2023 seasons were determined. The fungal isolates were identified as <i>Fusarium oxysporum</i> KT224063, <i>Pythium debaryanum</i> OP823136, and <i>Rhizoctonia solani</i> OP823124, while the <i>Bacillus</i> isolates were identified as <i>B. subtilis</i> OP823140 and <i>B. amyloliquefaciens</i> OP823147 on the basis of the rRNA gene sequences. The dual culture test revealed that <i>B. subtilis</i> outperformed <i>B. amyloliquefaciens</i> in resistance to <i>R. solani</i> and F. <i>oxysporum</i>, which were recorded as 28.33 and 33.00 mm, respectivley. In contrast, <i>B. amyloliquefaciens</i> caused the highest antagonistic effect against tested <i>P. debaryanum</i> fungus. Additionally, in a greenhouse experiment, tomato plants treated with each of these antagonistic <i>Bacillus</i> strains significantly suppressed fungal disease, displayed improved plant growth parameters, had an increased content of photosynthetic pigments, antioxidants enzymes, and total phenols, and an increased macronutrient content and yield during the two growing seasons. In conclusion, effective applications of <i>B. subtilis</i> and <i>B. amyloliquefaciens</i> had the potential to mitigate damping-off disease, which is caused by <i>F. oxysporum</i>, <i>P. debaryanum</i>, and <i>R. solani</i> in tomato plants, while simultaneously promoting growth dynamics.

Tomato mosaic disease, caused by tomato mosaic virus (ToMV), was studied under naturally elevated [CO₂] concentrations to simulate the potential impacts of future climate scenarios on the ToMV–tomato pathosystem. Tomato plants infected with ToMV were cultivated under two distinct [CO₂] environments: elevated [CO₂] (naturally enriched to approximately 1000 μmol mol⁻¹) and ambient [CO₂] (ambient atmospheric [CO₂] of 420 μmol mol⁻¹). Key parameters, including phytopathological (disease index, ToMV gene expression), growth-related (plant height, leaf area), and physiological traits (chlorophyll content, flavonoid levels, nitrogen balance index), were monitored to assess the effects of elevated [CO₂]. Elevated [CO₂] significantly reduced the disease index from 2.4 under ambient [CO₂] to 1.7 under elevated [CO₂]. Additionally, viral RNA expression was notably lower in plants grown at elevated [CO₂] compared to those under ambient [CO₂]. While ToMV infection led to reductions in the chlorophyll content and nitrogen balance index and an increase in the flavonoid levels under ambient [CO₂], these physiological effects were largely mitigated under elevated [CO₂]. Infected plants grown at elevated [CO₂] showed values for these parameters that approached those of healthy plants grown under ambient [CO₂]. These findings demonstrate that elevated [CO₂] helps to mitigate the effects of tomato mosaic disease and contribute to understanding how future climate scenarios may influence the tomato–ToMV interaction and other plant–pathogen interactions.

Some of the key pests of tomatoes are virus vectors, such as whiteflies, green peach aphids, and thrips, mainly because there is a lack of full resistance to the transmitted viruses. Alternatives to reduce this problem include the use of a push-and-pull strategy. Hence, this work assessed the association between Solanum habrochaites PI 1344117, used as a companion plant, and commercial tomato varieties over tomato virus vectors and the yield quality and quantity. Field and greenhouse trials were run during the 2015, 2016, 2018, and 2019 seasons. The treatments were BRS Tospodoro and BRS Tyão cultivated as monocrops and associated with PI-134417. The number of these insects was assessed by directly counting ten plants per plot and using captures on yellow sticky traps settled in the center of the plots. The yield and the number of irregularly ripening fruits (a symptom caused by whiteflies) were also measured. Both commercial cultivars gained from the protective effect of PI 134417, expressed by the significant reduction in the virus vectors on the plants. It was also noticed that there was a reduction in the number of irregularly ripening fruits, improving the fruit quality. These results encourage the use of wild and commercial tomato genotypes in association with implementing strategies to control tomato virus vectors, reducing the need to rely only on a chemical control.

Abstract Background Plant breeding research heavily relies on wild species, which harbor valuable traits for modern agriculture. This work employed a new introgression population derived from Solanum pennellii (LA5240), a wild tomato native to Peru, composed of 1,900 genotyped backcross inbred lines (BILs_BC2S6) in the tomato inbreds LEA and TOP cultivated genetic backgrounds. This Peruvian accession was found resistant to the most threatening disease of tomatoes today, caused by the tobamovirus tomato brown rugose fruit virus (ToBRFV). Results The BILs were inoculated and genotyped for 5000 single primer enrichment technology (SPET) markers and phenotyped for virus presence, using ELISA, and for visual symptoms in the terminal shoot, axillary shoots, and fruits. Growth of the recombinant BILs in a highly infected greenhouse enabled the mapping of a quantitative trait locus (QTL) for resistance to ToBRFV to chromosome 2 next to tomato mosaic-1 (Tm-1). The QTL reduced the ELISA values and the symptoms of the axillary shoots in both TOP and LEA BILs. Another locus for resistance was mapped to chromosome 3, which protected the terminal and axillary shoots of the TOP BILs only. A strong QTL for fruit susceptibility to ToBRFV was mapped to chromosome 7 only in the LEA background. Conclusion Taken together, S. pennellii loci conferring resistance and susceptibility act in a tissue-specific manner and are modified by genetic background.

Tomato (<i>Solanum lycopersicum</i> L.) is a major economic vegetable crop globally, yet it is prone to gray mold disease caused by <i>Botrytis cinerea</i> infection during cultivation. Caffeoyl shikimate esterase (CSE) is a crucial component of the lignin biosynthesis pathway, which significantly contributes to plant stress resistance. Therefore, investigating the expression patterns of <i>SlCSE</i> after <i>Botrytis cinerea</i> infection may offer a theoretical foundation for breeding resistant tomato varieties. In this study, 11 <i>SlCSE</i> family members were identified from the tomato genome using bioinformatics analyses. Public transcriptome databases and RT-qPCR experiments were used to analyze gene expression in tomato tissues, responses to <i>Botrytis cinerea</i> infection, and the temporal characteristics of the response to 2-ethylfuran treatment during infection. These experiments resulted in the identification of the key gene <i>SlCSE06</i>. Transgenic tomato lines that overexpressed <i>SlCSE06</i> were constructed to examine their resistance levels to gray mold disease. Many <i>SlCSE</i> genes were upregulated when tomato fruit were infected with <i>Botrytis cinerea</i> during the ripening stage. Furthermore, 24 h after treatment with 2-ethylfuran, most <i>SlCSE</i> genes exhibited increased expression levels compared with the control group, but they exhibited significantly lower levels at other time points. Thus, 2-ethylfuran treatment may enhance the responsiveness of <i>SlCSEs</i>. Based on this research, <i>SlCSE06</i> was identified as the key gene involved in the response to <i>Botrytis cinerea</i> infection. The <i>SlCSE06</i>-overexpressing (OE6) tomato plants exhibited a 197.94% increase in expression levels compared to the wild type (WT). Furthermore, the lignin content in OE6 was significantly higher than in WT, suggesting that the overexpression of <i>SlCSE06</i> enhanced lignin formation in tomato plants. At 5 days post-inoculation with <i>Botrytis cinerea</i>, the lesion diameter in OE6 decreased by 31.88% relative to the WT, whereas the lignin content increased by 370.90%. Furthermore, the expression level of <i>SlCSE06</i> was significantly upregulated, showing a 17.08-fold increase compared with the WT. These findings suggest that 2-ethylfuran enhances the activation of the critical tomato disease resistance gene <i>SlCSE06</i> in response to gray mold stress, thereby promoting lignin deposition to mitigate further infection by <i>Botrytis cinerea</i>.

ABSTRACT Soil conditioners have humic acid levels which can control nematodes and promote plant nutrition. The objective of this work was to evaluate different concentrations and doses of commercial soil conditioner Premium® on motility, mortality, hatching, infectivity and reproduction of Meloidogyne incognita in tomato. In order to evaluate motility, mortality, and hatching, second stage juveniles (J2) or eggs were subjected to incubation at different concentrations of soil conditioner. To evaluate infectivity and reproduction, infested soil with M. incognita were mixed to different concentrations of commercial soil conditioner. Thirty-day-old tomato seedlings (cv. Kada) were transplanted into the pots and after 30 days the numbers of galls, egg masses and eggs per gram of root were evaluated. The use of soil conditioner drastically reduced motility at a concentration of 66.67 g L-1 and caused mortality above 98% in M. incognita J2 at 133.33 g L-1. Exposure of eggs to soil conditioner reduced J2 hatching by more than 50% at a concentration of 2.5 g L-1. Highest concentrations of soil conditioner provided lower infectivity and reproduction of M. incognita in tomato. Soil conditioner at a dose of 5.0 g provided greater development of the root system, demonstrating the efficiency of this product.

Bacterial spot of tomato (BST), caused by <i>Xanthomonas euvesicatoria</i> pv. <i>perforans</i> (referred to as <i>X. perforans</i> thereafter), is widely distributed globally, including Florida, and reduces fruit quality and yield in tomato fields. Currently, copper-based bactericides are widely used for this disease control; however, the effectiveness of these treatments has diminished due to the emergence of copper-tolerant strains. Therefore, there is a need for novel chemical controls against BST. In this study, we investigated hexanoic acid (HA) as an alternative against copper-tolerant strains of <i>X. perforans</i> through laboratory, greenhouse, and field experiments. In vitro experiments demonstrated HA had a lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) compared to copper sulfate, with values of 512 and 1024 mg/L for HA versus 1024 and 2048 mg/L for copper sulfate. HA exhibited bactericidal activity within 1 h at 512 and 1024 mg/L. In greenhouse trials, HA applied at 512 and 1024 mg/L two days before inoculation significantly reduced disease severity compared to untreated controls and Kocide 3000 (copper hydroxide) + Penncozeb. However, field trials indicated that while HA reduced disease severity relative to the untreated control, it did not outperform the grower standard commercial bactericide ManKocide (copper hydroxide + mancozeb), nor did it improve total yield. Previous studies have shown the antimicrobial activity of HA against various other phytopathogens, but this study is the first to demonstrate the potential of hexanoic acid for controlling BST.