Fresh Market Tomatoes Research Articles

Breeding tomatoes suitable for processing with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight

India is the second largest producer of tomato with 11 per cent global share and cultivated on an estimated area of 0.76 million hectares with productivity of 24 tonnes per hectare. Less than 1% of the produce is processed when compared to 26% in other major producing countries. Of the estimated more than 41 million tonnes of tomato processed globally, only 130,000 tonnes were processed in India and domestic demand for processed tomato products is expanding at an estimated 30% annually. At present traditional fresh market tomato cultivars are being processed though such cultivars are unsuitable for processing. Processors in India are looking for high yielding tomato cultivars with high total soluble solids (5-6 º Brix), acidity not less than 0.4%, pH less than 4.5 and uniform red colour with a/b colour value of at least 2. In addition, firm fruited tomato cultivars with joint less pedicel (j2) which facilitate mechanical harvesting or rapid hand picking. ICAR-Indian Institute of Horticultural Research has recently developed two high yielding F1 hybrids in tomato viz: Arka Apeksha and Arka Vishesh suitable for processing. On evaluation for three years, both the hybrids recorded good level of total soluble solids (4.5-5º Brix) and colour value of 2. Further, both the hybrids had high yield potential (80-90 tonnes / hectare) with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight. Arka Apeksha and Arka Vishesh were also bred with jointless pedicel making them suitable for mechanical harvesting. Our experimental studies on vine storability revealed that all the fruits were intact on plants even 110 days after transplanting in the main field facilitating once over harvest.

Vigorous rootstocks improve yields and increase fruit sizes in grafted fresh market tomatoes

Grafting high yielding tomato cultivars (Solanum lycopersicum L.) onto vigorous rootstocks can increase marketable yields, but questions remain regarding optimal cultural and growing conditions such as pinching and plant spacing. This study addressed some of the dynamics between grafted plants and cultural practices. Two scions, ‘Tasti-Lee’ (TL) and ‘Mountain Fresh Plus’ (MFP) were grafted onto each of three rootstocks, ‘Beaufort’, ‘Arnold’, and ‘Shield’. Plants were pinched (removal of main shoot to induce both axillary shoots to grow) or non-pinched, and spaced at 56 or 61 cm. All 32 grafted treatments were compared to the grower standard: non-grafted TL and MFP spaced at 46 cm, which were non-pinched. Fruit quality traits including soluble solids content, pH, lycopene concentration, and titratable acidity were recorded for fruit harvested from tomatoes grafted onto ‘Arnold’, ‘Beaufort’, ‘Shield’ and non-grafted TL. The overall effect of grafting TL and MFP onto vigorous rootstocks ‘Arnold’, ‘Beaufort’, and ‘Fortamino’ increased marketable yields per hectare by 24-35% compared to non-grafted grower standards. The rootstock ‘Shield’ did not significantly increase yields with either scion. TL had a more positive response to grafting than MFP. ‘Arnold’, ‘Beaufort’, and ‘Fortamino’ significantly increased TL fruit size, but the fruit size results were not as significantly impacted by graft treatments for MFP. Plants spaced at 56 compared to 61 cm generated similar yields. Pinched plants significantly increased yields over non-pinched plants by 15% in 2018 but did not impact yield in 2017. No consistent difference was observed between pinched and non-pinched plants with regard to fruit size, only plants grafted with ‘Shield’ benefited significantly from being pinched. Soluble solids content, pH, total lycopene concentration, and titratable acidity differed slightly between grafted and non-grafted plants but was unlikely to positively or negatively affect overall perception of fruit quality in tomatoes. A partial budget analysis revealed that grafting with ‘Arnold’ or ‘Beaufort’ consistently increased profits in this low-disease field.

Salmonella transfer potential between tomatoes and cartons used for distribution

Corrugated fiberboard boxes (cartons) can be reused during fresh market tomato packing and repacking. The fate of Salmonella on the new, used, and dirty tomato packaging cartons, and Salmonella transfer between tomatoes and new, used, and dirty packaging cartons was assessed. Mature green tomatoes or blank cartons were spot inoculated with cocktail of rifampicin-resistant Salmonella strains before touching cartons/tomatoes at 0, 1, or 24 h postinoculation. Tomatoes were placed on new, used, and dirty carton squares (5 by 5 cm) for 0, 1, and 7 days of contact at 12°C and 25°C with a relative humidity value of 85%. Transfer coefficients (TCs) were calculated for all conditions. Salmonella populations decreased following inoculation by 2–3 log units during 24 h drying regardless of storage temperature; the presence of debris enhanced survival at 12°C. In general, the highest transfer rates occurred with wet inoculum. The highest Salmonella transfer was calculated for wet inoculated tomatoes with 7 days of contact time at 25°C (TC = 14.7). Increasing contact time decreased TCs for new cartons, but increased TCs for used and dirty cartons. Regardless of carton condition or storage temperature, a greater population of Salmonella was transferred from tomatoes to cartons than from cartons to tomatoes. Salmonella transfer between tomatoes and cartons is highly dependent on moisture, with increased levels of moisture increasing transfer, highlighting the importance of harvesting and packing dry tomatoes.

Weed Management Strategies for Tomato Plasticulture Production in Florida.

Florida is the top producer of fresh market tomatoes in the U.S., with an average production of 0.4 million metric tons. Tomatoes are commercially grown on plastic mulched raised beds in Southwest Florida, the primary production region in the state. Low tomato yield in plasticulture production is often associated with the poor control of nutsedge species. Nutsedge management, therefore, remains a critical production challenge for tomato growers in Florida. Sandy soil in this region promotes herbicide movement after heavy rainfall or irrigation, affecting weed suppression. This will also potentially impact the timely establishment of new tomato transplants and, consequently, the crop vigor if the herbicides get into the root zone. This review aims to present and discuss an overview of available options to safely manage major weeds of tomatoes, including nutsedge species, in plasticulture production. In addition, this review seeks to discuss an approach for utilizing herbicide adjuvants, such as spray deposition agents or oil binding agents, to improve herbicides' efficacy and tomato crop safety by enhancing their retention in plastic mulched raised beds.

Field evaluation of CRISPR-Cas9-driven brachytic and jointless pedicel tomatoes identifies an association between the high extra-large-sized fruit yield of the brachytic-mediated shortened tomato and the jointless2

Fresh-market tomato is one of the most important vegetables in the United States (US), and novel, cost-effective labor solutions are an important issue in current fresh-market tomato production. The shortened stem driven by the brachytic (br) and the jointless pedicel driven by the jointless2 (j2) are two important traits that would contribute to knowledge-based breeding; based on these traits, an appropriate plant architecture can be designed for ground cultivation systems that will ultimately enable mechanical harvesting. We aimed to evaluate the effect of CRISPR-Cas9-driven shortened plant architecture and jointless pedicel on the yield and horticultural performance of fresh-market tomatoes using a ground cultivation system in an open field. We conducted field trials during three successive seasons in 2020 and 2021 using the fresh-market tomato variety Fla. 8059 (a non-brachytic jointed pedicel tomato; BR/BR:J2/J2; wild-type) and its three different CRISPR-Cas9-driven mutants, a brachytic jointed pedicel Fla. 8059 (br/br:J2/J2), a non-brachytic jointless pedicel Fla. 8059 (BR/BR:j2/j2), and a brachytic jointless pedicel Fla. 8059 (br/br:j2/j2). Field evaluations confirmed that the total yield of the mutants was not significantly different from the yield of the wild-type. However, there was a significant association between the high extra-large-sized fruit yield of the br mutant and the j2 mutation. Field evaluations also revealed a clear positive impact of the br mutation on the high proportion of fruits laying on the raised plastic bed. Our results contribute to the optimization of fresh-market tomato architecture for developing shortened jointless pedicel varieties and the adoption of low input management practices.

Optimizing the application of acibenzolar-S-methyl and copper to control bacterial spot on fresh-market tomato

This study aimed to adjust the number of applications of acibenzolar-S-methyl (ASM) and copper in an integrated program for the control of bacterial spot on fresh-market tomato. Two field trials were carried out during 2018 and 2019. Four sets of number of weekly applications of ASM were evaluated (7, 9, 11, and 13 applications). In addition to these, four other treatments were included: two as a tank mixture compound [13 weekly applications of ASM + biostimulant and nine applications of ASM + copper oxychloride]. Copper oxychloride was applied after ASM treatments in order to complete 13 applications per growing season. Copper oxychloride and untreated plots were used as a control. The variables evaluated were bacterial spot severity, total yield, and yield per classes of fruit according to the Brazilian market standards. Benefit-cost ratio (B/C) was calculated considering the income increase of a given treatment in relation to the untreated control. The disease ratings and yield data were subjected to ANOVA and the means tested for significance by Fisher, Dunnett, and orthogonal contrasts comparison tests. Regression analysis were carried out with the disease ratings to evaluate the ASM number of applications. As the number of ASM applications increased, disease severity decreased, although, the best B/C was obtained with seven applications of ASM, followed by copper applications until the end of the cycle. The tank mixture compound treatments did not result in economic gain increase. Moreover, disease severity was significantly high when ASM was applied in tank mixture with copper.

Sensitivity and Recovery of Tomato Cultivars Following Simulated Drift of Dicamba or 2,4-D

Tomato (Solanum lycopersicum L.) plants are commonly injured by the off-target movement of synthetic auxin herbicides. A greenhouse and a field trial were conducted to determine the relative tolerance of eight fresh market tomato cultivars to drift-simulating rates of dicamba or 2,4-D. Tomato cultivars included ‘BHN 589’, ‘Celebrity’, ‘Florida 91’, ‘Mountain Merit’, ‘Primo Red’, ‘Red Deuce’, ‘Red Morning’, and ‘Skyway’. Dicamba (3,6-dichloro-methoxybenzoic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) were applied at 2.8 g ae ha−1 and 5.3 g ae ha−1-D, respectively. By 14 weeks after treatment (WAT), herbicide-treated plants of each cultivar produced less total and marketable yield than their respective nontreated control in the greenhouse trial. For most cultivars, dicamba-treated plants had less marketable yield than 2,4-D-treated plants in the greenhouse. Herbicide treatments also reduced total and marketable yields of each cultivar when compared with their control in the field study at 14 WAT, except for ‘Mountain Merit’. The severity of yield loss from herbicide treatments was cultivar-dependent. Field-grown ‘Skyway’ plants treated with dicamba produced the lowest marketable yield. In contrast, herbicide-treated plants of ‘Florida 91’ produced high marketable yields in the field, but ‘Red Deuce’ plants receiving 2,4-D were also highly productive. Herbicide residue in fruit sampled the third week of the harvest was nondetectable. Because the type of auxin herbicide drift is often unanticipated, ‘Florida 91’ may be the preferred cultivar for cultivation among those tested to maximize tomato production in the field.

Evaluation of the competitiveness of fresh tomato

The existence of international trade and related trade theory are closely related to competitiveness. The following study focuses on the competitiveness of Hungary, which studies the development of comparative advantage in terms of tomato for fresh consumption among horticultural products. As a consequence, the main objective is whether Hungary has comparative advantage over EU-28 countries in case of fresh market tomato. Data in the study were provided by FAOSTAT database. The study period focuses on results from 2004 to 2019, breaking them down into 5-year (average) cycles. The method chosen was the RCA index group, the most widely recognized and applied index group for calculating comparative advantage. Although Hungary is not a significant vegetable-producing country in Europe, the fruit and vegetable sector accounts for 10-13% of the production value of agriculture. Regarding the results, it can be stated that Hungary does not have comparative advantage in case of tomato products. With respect to values of the tomato sector, the RCA index is in the range of 0<RCA≤1, therefore we have no comparative advantage. Spain and the Netherlands have stable competitive advantage. These countries show weak comparative advantage in each period studied, as the indicator values exceed 1 but do not reach 2.

Effect of grafting and cover crop quality on nitrogen uptake from different pools by drip irrigated heirloom tomatoes in an open field trial

Fresh-market tomatoes (Lycopersicon esculentum Mill.) are increasingly produced with subsurface drip irrigation in California, as growers adapt to decreased water availability. Drip irrigation improves water use efficiency, but may reduce the soil volume where conditions are optimal for microbial and root activity. This poses complications for organic growers, whose cropping systems are dependent on microorganisms to convert the nitrogen (N) from organic sources into plant-available N. To investigate grafting as a potential practice to increase access to N, grafted and non-grafted “Brandywine” heirloom tomatoes were grown with drip irrigation in a two-year field trial. The three rootstocks were “Maxifort,” “Fortamino,” and “DRO138TX.” Prior to each growing season, a legume cover crop mix was grown and labeled with 15N ammonium sulfate to track tomato N uptake from cover crop residues. There were no significant differences in yield, N uptake and N partitioning in the plants due to rootstock treatments. Leaf analyses suggested that the tomato plants were not N deficient in either year. However, there was a significant difference in total N uptake from cover crop residues between years. This was caused by large differences in N concentration in the cover crop. Plants responded to a lower N availability by producing less vine biomass, while producing the same fruit yield. A budget revealed that the tomato plants accessed a considerable amount of N from the soil below 60 cm of the profile to cover their demand.

How Soil Covers Can Affect the Dynamics of Temperature, Soil Moisture, and Productivity of Creeping Fresh Market Tomatoes?

The aim was to evaluate the influence of soil covers on the dynamics of soil temperature and moisture, canopy air temperature, and yield of creeping fresh market tomatoes. The experiment was carried out in randomized blocks design, using the tomato cultivar Thaise, with 5 treatments, 4 replications, with different soil covers: a) Uncovered soil (conventional planting); b) Mulching (double-sided plastic film - black and white); c) Sorghum; d) Sudan grass and e) Pearl millet), cultivated in Tangará da Serra, Mato Grosso, Brazil. Soil temperature was monitored at depths of 5, 10, 20, and 30 cm and in the crop canopy, using thermocouple sensors of the type "K". Soil moisture was monitored in the 0 to 30 cm layer, using of time-domain reflectometry (TDR) probes. Soil temperature and moisture were evaluated throughout the cycle and, in the end, the total and commercial yield of tomato crop. Soil covers have a positive influence on soil temperature and moisture in the cultivation of creeping fresh market tomatoes so that soil cover with mulching provides the highest soil temperature in the early stages of development and covers with mulching and pearl millet provide the highest values of soil moisture. The highest total and commercial yield of tomato were in the soil cover with mulching, with 110.71 and 75.93 t ha-1, respectively, presenting ideal ranges of temperature and soil moisture, so that the other treatments do not differ from each other, with the average total yield of 91.45 t ha-1.

LoRaWAN based internet of things (IoT) system for precision irrigation in plasticulture fresh-market tomato

Precision irrigation with sensors has proven to be effective for water saving in crop production. An Internet of Things (IoT) system is necessary for monitoring real-time data from sensors and automating irrigation systems. Long-range wide-area network (LoRaWAN), a type of low-power wide-area network (LPWAN), is a low-cost and easily implemented IoT system which can be used for precision crop irrigation. In this study, a LoRaWAN based IoT system was developed and evaluated as a precision irrigation tool on fresh-market tomato production in a plasticulture system. Four irrigation scheduling treatments were designed and tested, including irrigation based on crop evapotranspiration (ET), soil matric potential sensors (Watermark 200SS-5) at -60 kPa (MP60) or -40 kPa (MP40), and GesCoN fertigation decision support system (DSS). The treatments were arranged based on a randomized complete block design with four replicates. System feasibility, irrigation water use efficiency (iWUE), and crop yield were evaluated. Throughout the season, the overall water use efficiencies were 22.2, 26.5, 27.9, and 28.4 kg·m−3 for ET, MP60, MP40, and GesCoN, respectively. The results indicated that treatment MP60 and GesCoN had 15.2 and 22.1% higher marketable fruit yield than ET, while, MP40 had 12.5% lower marketable yield compared to ET. Overall, the LoRaWAN-based IoT system performed well in terms of power consumption, communication, sensor reading, and valve control. These results suggested that the IoT system can be implemented for precision and automatic irrigation operations for vegetable and other horticultural crops with enhancing crop's water use efficiency and sustainability.

Steroidal alkaloid biosynthesis is coordinately regulated and differs among tomatoes in the red-fruited clade.

The tomato (Solanum spp.) clade of Solanaceae features a unique assortment of cholesterol-derived steroidal alkaloids. However, little quantitative data exists reporting the profile and concentration of these alkaloids across diverse fruit germplasm. To address the lack of knowledge regarding the chemical diversity, concentration, and genetic architecture controlling tomato steroidal alkaloids, we quantitatively profiled and genotyped two tomato populations representing diversity in the red-fruited clade. We grew 107 genetically diverse fresh market, processing, landrace, and wild tomato in multiple environments. Nine steroidal alkaloid groups were quantified using ultra-high performance liquid chromatography tandem mass spectrometry. The diversity panel and a biparental population segregating for high alpha-tomatine were genotyped to identify and validate quantitative trait loci (QTL) associated with steroidal alkaloids. Landraces and wild material exhibited higher alkaloid concentrations and more chemical diversity. Average total content of steroidal alkaloids, often dominated by lycoperoside F/G/esculeoside A, ranged from 1.9 to 23.3 mg 100 g-1 fresh wt. across accessions. Landrace and wild cherry accessions distinctly clustered based on elevated concentrations of early or late-pathway steroidal alkaloids. Significant correlations were observed among alkaloids from the early and late parts of the biosynthetic pathway in a species-dependent manner. A QTL controlling multiple, early steroidal alkaloid pathway intermediates on chromosome 3 was identified by genome-wide association studies (GWAS) and validated in a backcross population. Overall, tomato steroidal alkaloids are diverse in the red-fruited clade and their biosynthesis is regulated in a coordinated manner.

A Consensus Genetic Map and Linkage Panel for Fresh-market Tomato

The first consensus genetic map in fresh-market tomato (Solanum lycopersicum) was constructed, combining genetic recombination data from two biparental F2 segregating populations derived from four different fresh-market tomatoes. Each F2 population was nominated by different academic tomato breeding programs located in major fresh-market tomato-producing areas of the United States, and chromosome-wide variation in recombination rates was observed between tomato populations based on the origin of their breeding programs. A consensus map constructed using 335 common single nucleotide polymorphism (SNP) sites found in both populations spanned 737.3 cM across 12 tomato chromosomes, with chromosome 2 containing more than 40% of the total SNPs and chromosomes 4, 5, 7, and 10 together representing less than 10% of the SNPs. There was a high degree of collinearity between the genetic and physical positions of those 335 SNP markers. The integration of 6553 SNP sites that were detected in either of the two populations with 335 common sites resulted in an extended consensus genetic map. The total length of the extended map was estimated to be 1997.9 cM, which was compatible with a previous estimate for large-fruited fresh-market tomato. A linkage panel for fresh-market tomato was also established using the combined dataset of the consensus map of 335 SNP loci and 73 SNP-genotyped core fresh-market tomatoes. An empirical genetic mapping study of the tomato brachytic trait using the linkage panel demonstrated the value of the consensus map and linkage panel for tomato research. The allelic information in the linkage panel will serve as a basis for SNP marker implementation, such as genotyping platforms and genomic association map, in tomato.

Supplemental Fumigant Placement Improves Root Knot and Fusarium Wilt Management for Tomatoes Produced on a Raised-Bed Plasticulture System in Florida's Myakka Fine Sand.

Fresh-market tomatoes are produced on a raised-bed plasticulture system that relies heavily on soil-applied preplant fumigants for the management of soilborne pathogens, nematodes, and weeds. Since the transition from methyl bromide to alternative fumigants, growers have experienced a resurgence of several soilborne pests and pathogens, including root-knot nematode caused by Meloidogyne spp. and Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici race 3. This resurgence is attributed to the inability of the alternative fumigants to effectively disperse through the soil in the same manner as methyl bromide. Two supplemental fumigation strategies, the application of chloropicrin (PIC) below bed edges (herein "supplemental PIC") and broadcast deep-shank applications of 1,3-dichloropropene (1,3-D), were evaluated in conjunction with standard raised-bed applications of Pic-Clor 60, Pic-Clor 80, and Pic 100 covered with a virtually impermeable film or a totally impermeable film. Large-plot replicated studies were conducted in two separate commercial tomato fields with a history of production losses caused by root-knot nematode and Fusarium wilt. Deep-shank 1,3-D applications significantly reduced the recovery of root-knot and total parasitic nematodes across field sites before the preparation of raised beds. Both supplemental PIC and deep-shank 1,3-D reduced root-knot galling and Fusarium wilt incidence, but the latter supplemental treatment statistically had the greatest impact. Fumigant applied within raised beds or plastic film had no significant effect on root-knot galling or Fusarium wilt. Although both supplemental fumigation strategies had a significant effect on pest and disease pressure, neither statistically improved tomato yields based on small subplot harvests. Controlled laboratory experiments confirmed the fungicidal activity of 1,3-D against F. oxysporum f. sp. lycopersici, with 75, 90, 95, and 99% lethal doses corresponding to estimated field application rates of 56.1, 93.5, 121.6, and 184.7 liters/ha, respectively. The results demonstrate how fumigant placement can improve pest and disease control activity with current fumigant alternatives to methyl bromide and further support the broader pesticidal activity of some chemical fumigants.

Sensory Traits and Consumer's Perceived Quality of Traditional and Modern Fresh Market Tomato Varieties: A Study in Three European Countries.

Consumer dissatisfaction with the flavor quality of many modern fresh market tomato varieties has fostered breeders’ interest in sensory quality improvement, and the demand for traditional varieties, which are generally associated with better flavor. To achieve further knowledge on the factors influencing the sensory quality and consumers’ preferences and perception, European traditional and modern fresh market tomato varieties were grown and evaluated in France, Italy, and Spain. Different growing conditions were tested in France (soilless vs. soil) and in Spain (open field vs. greenhouse), while in Italy fruits were evaluated at two ripening stages. Fruit quality was assessed by integrating physicochemical analyses, sensory profiles, and consumer tests. In all three countries, overall modern varieties were perceived as having more intense “tomato flavor” and “overall flavor” than traditional ones. In France and Spain, consumers’ preferences were more oriented towards modern varieties than traditional ones. Significant growing condition effects were found on sensory and physicochemical traits, while the effect on consumers’ overall liking was not significant, largely depending on the genotype. A fair agreement between product configurations from descriptive analysis by trained assessors and Check-All-That-Apply (CATA) questions by consumers was observed. Penalty-lift analysis based on CATA allowed identifying positive and negative drivers of liking.

Field Evaluation of CRISPR-Driven Jointless Pedicel Fresh-Market Tomatoes

Clustered regularly interspaced short palindromic repeats (CRISPR)-driven traits are commonly introduced into tomato (Solanum lycopersicum) in less than a year. Although CRISPR technology is highly suitable for rapid incorporation of new traits into plants with superior breeding backgrounds, the usefulness of these traits must be demonstrated prior to large-scale distribution of any new variety possessing them. The jointless pedicel trait is crucial for stem-free harvest of tomato fruits and is therefore an essential requirement for developing low-labor tomato varieties. We aimed to evaluate the effect of CRISPR-driven jointless pedicel trait on the yield and horticultural traits of fresh-market tomatoes. We conducted field trials during three consecutive seasons using three related genotypes of two elite fresh-market tomatoes, namely a jointed pedicel tomato, a CRISPR-driven jointless pedicel mutant of the jointed pedicel tomato, and a conventionally-bred jointless pedicel near isogenic line (NIL) to the jointed pedicel tomato. Field evaluations confirmed that the total and medium-, large-, or extra-large-size fruit yields of the CRISPR-driven mutants were not statistically different for those corresponding to their backgrounds and that the fruit yield stratified by fruit size might be varied under different growth conditions. We did not observe any negative correlation between the genotype and the fruit/abscission joint detachment force for any of the genotypes under study.

Optimizing Tomato Growth and Productivity Using Nitrogen and Irrigation Application Timing

Soil nutrients and water management practices according to the concept of 4R nutrient stewardship (right rate, right timing, right placement, and right source) can have significant benefits on crop productivity and reduce the negative effects of agricultural practices on the environment. Therefore, this present study evaluated the effects of nitrogen (N) application timing under different irrigation regimes on open-field, fresh-market tomato production in Florida. In this study, 2 N application timings applied at 25% pre-plant with 75% fertigation (BM), and 0 pre-plant with 100% fertigation (NB), were evaluated. The two N application methods were evaluates using three irrigation regimes: full irrigation (FI, 100% ETc), deficit irrigation (DI, 66% ETc), and regulated deficit irrigation (RDI, 66% ETc during the first 4 weeks after transplanting and 100% ETc afterward). The results showed that BM treatment significantly improved early-season tomato growth compared to NB treatment. The results also indicated that under RDI and DI irrigation conditions, tomato root length was lowest (average value of 13%) within the first 15 cm compared to 40% within 15–30 cm and 47% at 30–40 cm soil depths. Similar to plant growth, BM treatment significantly increased tomato yield (average valued 56.00 Mg ha−1) compared to the NB (average value 40.23 Mg ha−1). The application of DI throughout the growing season reduced tomato yield; however, there were no differences in yield under the RDI and FI irrigation regimes. Therefore, based on the results from this study, it can be concluded that, under Florida growing conditions, pre-plant N application is essential for tomato growth and productivity. Additionally, irrigation application using the RDI method could be successfully adopted in Florida tomato production for improved water savings without any negative effects on tomato growth and productivity.

Effect of environmental variability on fruit quality and phytochemical content of soilless grown tomato cultivars in a non-temperature-controlled high tunnel

The present study investigated the influence of environmental conditions (growing regions and/or fruit-harvesting periods) and cultivar on fruit phytochemical content and quality parameters of “salad-type” fresh market tomatoes grown in protected soilless culture under non-temperature-controlled high tunnels. Sixteen high yielding hybrid tomato cultivars of indeterminate growth were grown in three different regions (Tshwane, Eastern and Western regions) of a subtropical highland climate, and the fruits were harvested in three different periods of the growing season for fruit quality analysis. The Eastern region was in general the most ideal environment for increased fruit quality (particularly fruit electrical conductivity) and phytochemical content of soilless grown tomato cultivars in a non-temperature-controlled high tunnel. The fruit electrical conductivity was considerably high in this region, irrespective of its harvesting period. The potential to maximize a certain type of phytochemical or fruit quality parameter was cultivar-dependant. Cultivars responded differently to the changing environment. However, the fruit total soluble solids level of those cultivars showing superior performance was positively influenced by increased levels of thermal time accumulation and minimum relative humidity, while their fruit electrical conductivity level was reduced with increased vapour pressure deficit. On the contrary, the fruit pH level did not seem to be affected by the environment or cultivar type. Therefore, identifying appropriate growing environments for the tomato cultivars is crucial for improved phytochemical content and fruit quality parameters, contributing to nutrition security, improved income generation for farmers and overall societal well-being.

First report of Tomato brown rugose fruit virus infecting tomato in Florida, USA

Florida is a leading producer of fresh-market tomatoes (Solanum lycopersicum) in the US, a $262 million industry for the state. In October 2019, eight tomato plants showing chlorotic, cupped leaves and stunted foliage (Fig. 1) were collected from a c. 1.6 ha community garden in Alachua County, Florida. The symptoms observed were characteristic of Tomato yellow leaf curl virus (TYLCV). Samples were tested by PCR using TYLCV-specific primers by Navot et al. (1992). Three samples tested positive for TYLCV. Lateral flow immunoassay tests (“immunostrip assays”; Agdia, USA) for Pepino mosaic virus and Cucumber mosaic virus were negative. However, an immunostrip for Tobacco mosaic virus (TMV) gave a faint positive result for one of three TYLCV-positive sample, suggesting a mixed infection. Tobamovirus-like rigid rod-shaped particles of ∼300 nm in length, were also observed in leaf dips from this plant using an LVEM5 transmission electron microscope (DeLong America, USA). Tests for common tobamoviruses, i.e. TMV, Tomato mosaic virus, Tomato mottle mosaic virus, (Sui et al., 2017), Tobacco mild green mosaic virus (Cohen et al., 2006), and Tomato brown rugose fruit virus (ToBRFV) (Ling et al., 2019) were conducted using specific primers in RT-PCR with total RNA extracted using RNeasy® Plant Mini kits (Qiagen, Germany). Additionally, conventional PCR primers, DPI-782(5859nt-5879nt) = 5′-TAGCGAAGTGTGGAAACCTG-3′ and DPI-783(6154nt-6183nt) = 5′-GGTGCAGAGGACCATTGTAA-3′ (amplicon size of 342 bp), and primers and probes for a real-time RT-PCR Taqman assay DPI-784(6029nt-6049nt) = 5′-CCGAAACGTTAGACGCTACTC-3′, DPI-785(6106nt -6127nt) = ACCTGTTCCTTTGACCAA TTCT-3′, and DPI-787(6060nt-6083nt) TaqMan probe = 5′-ATG CAACGGTGGCTATAAGGA-3’) from the coat protein ∼5800-6130 nt region were developed for ToBRFV. Six of eight samples, including three TYLCV-positive samples, were positive for ToBRFV. The sequenced PCR products (GenBank Accession No. MW322766) were 98 to 99 % identical to ToBRFV isolates from Jordan and Mexico (KT383474, MK319944). The identification of ToBRFV was further confirmed by USDA-APHIS-PPQ-S&T laboratory (Laurel, Maryland, USA) by RT-PCR and sequencing. The Ct values of the real-time assay were in the range of 27 to 31. The weak positive result from the immunostrip, relatively high Ct values and co-infection with TYLCV suggest that ToBRFV was present in a low titre in these samples. ToBRFV was also detected in tomatoes imported from Mexico and for sale in grocery stores in Naples and Gainesville by University of Florida and Florida Department of Agriculture and Consumer Services (FDACS) around the same time (Batuman et al., 2020), Immediately following the survey, all solanaceous plants in the organic garden were destroyed. FDACS is taking all precautionary measures to test tomatoes produced in Florida. Further studies are needed to better understand the risk factors from this virus in Florida. The authors would like to thank Department of Plant Industry (DPI), Florida Department of Agriculture and Consumer Services (FDACS) for all assistance with the project.

COMPARATIVE ANALYSIS OF NET INCOMES FOR SUPPLY CHAIN ACTORS OF FRESH TOMATO IN BAUCHI STATE, NIGERIA

The study compared the net farm income of fresh tomato supply chain actors (SCAs) among central, western and northern zones of Bauchi State. Primary data were collected with the use of a structured questionnaire. Simple random sampling technique was used to select 658 supply chain actors (producers, wholesalers, and retailers). The data collected were analysed using farm budgeting technique and analysis of variance (ANOVA). The result reveals net incomes of N186025.35, N321883.48 and N 66858.45 for producers, wholesalers and retailers, respectively. Also, the study shows returns per naira invested on every one naira as N0.78, N0.29 and N0.2, minimum net incomes of N -314058.33, N -2499400, N-80250.00 and maximum net incomes of N979826.67, N 4929150.00, N 368050.0 for producers, wholesalers and retailers, respectively. The result shows significant differences in the net incomes of wholesalers and produce; wholesalers and retailers; and between retailers and producers at p < 0.05 and P<0.01 was observed. The result further reveals minimum costs incurred as N115122.50, N253450.00, N73470.00 and maximum costs incurred as N 805658.33, N4026350.00 and N 725570.00 for the SCAs. The result indicated significant differences in costs incurred between wholesalers and producers, wholesalers and retailers at P<0.01. The study concluded that fresh tomato production and marketing in the study area was profitable among the supply chain actors. It can also be said that there was significant differences in both the net incomes obtained and costs incurred by the supply chain actors among the zones. The study recommends that decisions on fresh tomato production and marketing be adjusted and re-established so as to optimise their profits. Also, SCAs can sell their products online by registering their product and location. This will allow easy access of the product by customers and it will help broaden fresh tomato market, which in turn will increase the income of the supply chain actors in the study area.