• The Journal of Bigdata
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• v.9 no.1
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• pp.61-73
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• 2024

Class imbalance is one of the significant challenges in deep learning tasks, particularly pronounced in areas with limited data. This study proposes a new approach that utilizes minimal labeled data for effectively classifying tomato leaf diseases. We introduced a recursive learning method using the YOLOv8 model. By utilizing the detection predictions of images on the training data as additional training data, the number of labeled data is progressively increased. Unlike conventional data augmentation and up-down sampling techniques, this method seeks to fundamentally solve the class imbalance problem by maximizing the utility of actual data. Based on the secured labeled data, tomato leaves were extracted, and diseases were classified using the EfficientNet model. This process achieved a high accuracy of 98.92%. Notably, a 12.9% improvement compared to the baseline was observed in the detection of Late blight diseases, which has the least amount of data. This research presents a methodology that addresses data imbalance issues while offering high-precision disease classification, with the expectation of application to other crops.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.143-150
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• 2007

A new virus-like disease of tomato showing chlorotic spots, malformation and necrosis on leaves, and chlorotic blotching, rings, and necrosis on fruits was observed around Sacheon, Gyeongsangnam-do, Korea in 2004. Host range analysis could not differentiate 4 field isolates collected from tomatoes showing different symptoms but identified them as Tomato bushy stunt virus (TBSV). TBSV-tsf2 isolate induced symptoms in indicator plants similar to those caused by the TBSV-C, -S and -Nf. As the isolate could not systemically infect Chenopodium quinoa, the isolate might belong to the previously described TBSV-S isolate. TBSV-tsf2 isolate caused similar cytological alterations that were similar to that generally caused by previously reported TBSV isolates. TBSV-tsf2 isolate, however, could be considered to belong to new strain of TBSV because masses of small electron-dense patches that were not observed from the previously described TBSV. The complete nucleotide sequences of the genomic RNA of 4739 nt excluding non-translated sequences at both termini have been determined and compared to sequences of other TBSV strains. The complete nucleotide sequence identity among TBSV isolates was 98.9% to 99.7%, and to the other tombusviruses ranged from 80.8% to 94.9%. Comparison of the amino acid sequences all five ORFs with those of other TBSV strains shows a similar genomic organization, and high percentage of amino acid sequence homology with TBSV-Nf than TBSV-S isolate. Since the TBSV symptoms were only observed in Sacheon fields where imported seeds from Japan were planted, the TBSV incidence probably caused by the planting contaminated tomato seeds and thus require more through quarantine procedure to prevent settlement of TBSV in Korea. Altogether, these results support that the Korean isolate of TBSV infecting tomato might be new strain.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.376-383
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• 2022

The current study, which consisted of two independent studies (laboratory and greenhouse), was carried out to project the hypothesis fungi-spray scheduling for leaf mold and gray leaf spot in tomato, as well as to evaluate the effect of temperature and leaf wet duration on the effectiveness of different fungicides against these diseases. In the first experiment, tomato leaves were infected with 1 × 10⁴ conidia·mL^-1 and put in a dew chamber for 0 to 18 hours at 10 to 25℃ (Fulvia fulva) and 10 to 30℃ (Stemphylium lycopersici). In farm study, tomato plants were treated for 240 hours with diluted (1,000 times) 30% trimidazole, 50% polyoxin B, and 40% iminoctadine tris (Belkut) for protection of leaf mold, and 10% etridiazole + 55% thiophanate-methyl (Gajiran), and 15% tribasic copper sulfate (Sebinna) for protection of gray leaf spot. In laboratory test, leaf condensation on the leaves of tomato plants were emerged after 9 hrs. of incubation. In conclusion, the incidence degree of leaf mold and gray leaf spot disease on tomato plants shows that it is very closely related to formation of leaf condensation, therefore the incidence of leaf mold was greater at 20 and 15℃, while 25 and 20℃ enhanced the incidence of gray leaf spot. The incidence of leaf mold and gray leaf spot developed 20 days after inoculation, and the latency period was estimated to be 14-15 days. Trihumin fungicide had the maximum effectiveness up to 168 hours of fungicides at 12 hours of wet duration in leaf mold, whereas Gajiran fungicide had the highest control (93%) against gray leaf spot up to 144 hours. All the chemicals showed an around 30-50% decrease in effectiveness after 240 hours of treatment. The model predictions in present study could be help in timely, effective and ecofriendly management of leaf mold disease in tomato.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.21-27
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• 1999

Nonpathogenic mutants of Xanthomonas campestris pv. glycines were generated with Omegon-Kim to isolate genes essential for pathogenicity and inducing hypersensitive response (HR). Three nonpathogenic multants and two mutants showing slow symptom development were isolated among 1,000 colonies tested. From two nonpathogenic mutants, 8-13 and 26-13, genes homologous to hrcC and hrpF of X. campestris pv. vesicatoria were identified. The nonpathogenic mutant 8-13 had a mutation in a gene homologous to hrpF of X. campestris pv. vesicatoria and failed to cause HR on pepper plants but still induced HR on tomato leaves. The nonpathogenic mutant 26-13 had an insertional mutation in a gene homologous to hrcC of X. campestris pv. vesicatoria and lost the ability to induce HR on pepper leaves but still caused HR on tomato plants. Unlike other phytopathogenic bacteria, the parent strain and these two mutants of X. campestris pv. glycines did not cause HR on tobacco plants. a cosmid clone, pBL1, that complemented the phenotypes of 8-13 was isolated. From the analysis of restriction enzyme mapping and deletion analyses of pBL1, a 9.0-kb Eco RI fragment restored the phenotypes of 8-13. pBL1 failed to complement the phenotypes of 26-13, indicating that the hrcC gene resides outside of the insert DNA of pBL1. One nonpathogenic mutant, 13-33, had a mutation in a gene homologous to a miaA gene encoding tRNA delta (2)-isopentenylpyrophosphate transferase of Escherichia coli. This indicated that tRNA modifications in X. campestris pv. glycines may be required for expression of genes necessary for pathogenicity. The mutant 13-33 multiplied as well as the parent strain did in the culture medium and in planta, indicating that loss of pathogenicity is not due to the inability of multiplication in vivo.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.173-180
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• 2007

The full-length cDNA of LeAPR1 encoded a protein of 461 amino acid residues, which contained homology with phosphoadenosine phosphosulphate reductase (PAPS reductase) in N-terminal and an adenylylsulfate reductase in N-term and C-terminal. Analysis of the deduced amino acid sequence of LeAPR1 revealed that it shares high sequence identity with potato StAPR (96% identity)(Gene bank accession no. CDC44841). We found that multiple copies of LeAPR1 gene are present in the tomato genome through southern blot using genomic DNA was digested with 3 different restriction enzymes. The expression of LeAPR1 was also examined in various organs and its expression was also detected at high levels in roots and stems. Only high amounts of LeAPR1 transcripts were detected at high transcripts in the leaves at time 0, and then reduced as the plant stressed by the NaCl and abscisic acid (ABA). After 24h treatment of NaCl and ABA were showed increasing patterns of LeAPR1 gene. Time course of LeAPR1 gene expression was examined under oxidative stresses from metyl viologen (MV) and hydrogen peroxide ($H_2O_2$). In the presence of 10 mM $H_2O_2$ and $50\;{\mu}M$ MV, the levels of LeAPR1 transcript in leaves decreased after 1 h, and then increased strongly, peaked at 24 h. Our results indicated that LeAPR1 may play a role function of circadian regulation involved in abiotic stresses signaling pathways.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.173-179
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• 2003

This study was established to control the overgrowth of cucumber and tomato plug seedlings by controlling of irradiation timings light intensities of red (R) light. Compared with the control, end-of-day (EOD) timing of R irradiation significantly reduced the seeding heights by 21.3% and 14.2% in cucumber and tomato, respectively. In addition, both plant seedlings treated with R light at EOD timing had the thickest stem diameter. Tomato seedlings treated with R light at EOD showed th highest chlorophyll content and the smallest leaf size. Dry weights of above ground plant tissue in both plant seedlings were significantly reduced by EOD R light treatment. And both plant seedlings treated with EOD treatment had the lowest T/R ratio, and the highest compactness rates. The increased intensities of R light resulted in the shorter plant heights in cucumber and tomato plant seedlings. It also reduced the length of hypocotyls and internodes and the size of leaves in the both seedlings. Elevated R light intensities tended to increase the stem diameter and chlorophyll contents. Dry weights of above ground plant tissue and roots in both plant seedlings were reduced by the elevated R irradiation. Cucumber seedlings treated with 2 and 8 $mol{\cdot}m^{-2}{\cdot}s^{-1}$ and tomato seedlings treated with 8 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ had significantly lower T/R ratio the other treatments tested.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.32-39
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• 2012

Efficacy of different control methods was evaluated for disease management of tomato bacterial wilt caused by $Ralstonia$ $solanacearum$. All six chemical pesticides applied to the bacterial suspension showed $in$ $vitro$ bactericidal activities against $R.$ $solanacearum$. Minimal inhibitory concentrations (MICs) of copper hydroxide (CH), copper hydroxide-oxadixyl mixture (CH+O), and copper oxychloride-dithianon mixture (CO+D) were all 200 ${\mu}g/ml$; MIC of copper oxychloride-kasugamycin (CO+K) mixture was 100 ${\mu}g/ml$; MICs of both streptomycin- validamycin (S+V) and oxine copper-polyoxine B mixture (OC+PB) were 10 ${\mu}g/ml$. Among these chemical pesticides, treatment of the detached tomato leaves with the 5 pesticides (1 mg/ml), except for OC+PB delayed early wilting symptom development caused by the bacterial inoculation ($10^6$ and $10^7$ cfu/ml). Four pesticides, CH, CH+O, CO+K and S+V, showed disease protection in pot analyses. Six plant essential oils, such as cinnamon oil, citral, clove oil, eugenol, geraniol and limonene, differentially showed their antibacterial activities $in$ $vitro$ against $R.$ $solanacearum$ demonstrated by paper disc assay. Among those, cinnamon oil and clove oil exert the most effective activity for protection from the wilt disease caused by the bacterial infection ($10^6$ cfu/ml). Treatment with cinnamon oil and clove oil also suppressed bacterial disease by a higher inoculum concentration ($10^7$ cfu/ml). Clove oil could be used for prevention of bacterial wilt disease of tomato plants without any phytotoxicity. Thus, we suggest that copper compounds, antibiotics and essential oils have potency as a controlling agent of tomato bacterial wilt.

• Research in Plant Disease
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• v.11 no.2
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• pp.213-216
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• 2005

Tomato spotted wilt virus (TSWV) occurred abruptly with a high incidence rate in 14 vegetable crops in Anyang area, Gyunggido in 2004. TSWV was identified by the symptoms on the indicator plants, immunocaptured reverse transcription-polymerase chain reaction (IC/RT-PCR), virion captured (VC)RT-PCR and RT-PCR using total RNA from the infected plants. Vegetable crops infected with TSWV included table tomato, cherry tomato, red pepper, lettuce, chicory, red leaf chicory, red mustard, dragon tongue, treviso, potato, perilla, sesame, pumpkin, and ssamchoo (hybrid of oriental cabbage and cabbage). The incidence of TSWV in fields ranged from 30 to $100\%$. TSWV usually produced necrosis, wilt and/or severe mosaic with typical single or double ring spots on the leaves. TSWV could be detected in Frankliniella occidentalis collected from the crops in the fields with $90\%$ rate by IC/RT-PCR.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.266-274
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• 2010

This study aim to investigate fundamentally the growth and physiological responses of tomato plants in responses to two different levels of water deficit, a weak drought stress (-25 kPa) and a severe drought stress (-100 kPa) in soil. The two levels of water deficit were maintained using a micro-irrigation system consisted of soil sensors for the real-time monitoring of soil water content and irrigation modules in a greenhouse experiment. Soil water contents were fluctuated throughout the 30 days treatment period but differed between the two treatments with the average -47 kPa in -25 kPa set treatment and the -119 kPa in -100 kPa set treatment. There were significant differences in plant height between the two different soil water statuses in plant height without differences of the number of nodes. The plants grown in the severe water-deficit treatment had greater accumulation of biomass than the plants in the weak water-deficit treatment. The severe water-deficit treatment (-119 kPa) also induced greater leaf area and leaf dry weight of the plants than the weak water-deficit treatment did, even though there was no difference in leaf area per unit dry weight. These results of growth parameters tested in this study indicate that the severe drought could cause an adaptation of tomato plants to the drought stress with the enhancement of biomass and leaf expansion without changes of leaf thickness. Greater relative water content of leaves and lower osmotic potential of sap expressed from turgid leaves were recorded in the severe water deficit treatment than in the weak water deficit treatment. This finding also postulated physiological adaptation to be better water status under drought stress. The drought imposition affected significantly on photosynthesis, water use efficiency and stomatal conductance of tomato plants. The severe water-deficit treatment increased PSII activities and water use efficiency, but decreased stomatal conductance than the weak water-deficit treatment. However, there were no differences between the two treatments in total photosynthetic capacity. Finally, there were no differences in the number and biomass of fruits. These results suggested that tomato plants have an ability to make adaptation to water deficit conditions through changes in leaf morphology, osmotic potentials, and water use efficiency as well as PSII activity. These adaptation responses should be considered in the screening of drought tolerance of tomato plants.