Diversity and occurrence of major diseases of vegetables and fruit crops during spring season at Aanbukhaireni rural municipality of Tanahun district, Nepal

A survey has been conducted to assess the diversity and occurrence of major vegetables and fruits cultivated in Aanbukhaireni rural municipality of Tanahun district, Nepal during spring season of 2019.The surveyed areas were Satrasayaphant, Baradiphant and Dumridanda villages of ward no 1, Yeklephant, Markichowk and Pateni villages of ward no2 , Gaadapani village of ward no 3, Saakhar village of ward no 4 and Ghummaune village of ward no. 5. The surveyed area consists of upper tropical and sub tropical climate. The total no of farmers field selected for the survey was 34, 32, 24, 17 and 21 from ward no 1,2,3,4 and 5 respectively.The major vegetables cultivated during survey period in the surveyed area were bean, bitter-gourd, brinjal, chilli, cowpea, cucumber, okra, pumpkin, sponge-gourd, tomato, snake-gourd and bottle-gourd. Similarly, the fruits found in the region were banana, papaya, grapes, mango, litchi, peach, guava, lemon, mandarin orange etc. The major diseases of vegetables noticed were early blight, late blight, cercospora leaf spot, powdery mildew, downey mildew, fruit rot, bacterial wilt, bacterial spot, leaf curl and mosaic. In case of fruits, sigatoka leaf spot, panama wilt, black rot, algal leaf spot, canker, root rot, foot rot, sooty mold, red rust, anthracnose, rust, mosaic, alternaria leaf spot, downey mildew and leaf curl were the major diseases. The higher disease incidence (70%) and severity (48%) in vegetables were recorded in ward no 2 where as the lower incidence (45.2%) and severity (37.71%) were found in ward no 4. Similarly, the higher fruit disease incidence (70.24%) and severity (51.27%) in ward no 1 followed by ward no 2 with disease incidence and severity of 66.79% and 45.14% respectively. The reasons for those results are low educational level, lack of best bet technology, no proper irrigation and fertilizer, unavailability of pesticides for controlling the diseases. This study will be useful to identify the major diseases of vegetables and fruits of terai and inner terai region of Nepal and applying control measure, looking for the best possible solutions.

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Diagnosis and prescription for Cercospora leaf spot of chilli

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v13i2.28779 ◽

2016 ◽

Vol 13 (2) ◽

pp. 191-196

Author(s):

MS Islam ◽

K Fatema ◽

KMB Alam ◽

MB Meah

Keyword(s):

Leaf Spot ◽

Plant Disease ◽

Disease Incidence ◽

Cost Ratio ◽

Cercospora Leaf Spot ◽

Benefit Cost Ratio ◽

Benefit Cost

The experiments were carried out during 2009 to 2013 on diagnosis and prescriptions for management of Cercospora leaf spot of chilli. The studies were undertaken in 250 growers field of five upazillas viz. Mymensingh sadar, Kushtia sadar, Kumarkhali, Chandina and Sher-e-Bangla Nagar. The highest disease incidence (38.6%) and severity (17.4%) of Cercospora leaf spot of chilli was recorded. Cercospora capsici produced leaf spot of chilli. The prescription given by Plant Disease Diagnostic Clinic (PDDC) was effective in the farmers field against the disease. Cercospora leaf spot of chilli is the most important diseases of spices in Bangladesh as the diseases significantly reduce the quality and yield. Prescription was Bavistin-50 DF @ 1g/l sprayed 4 times at 15 days interval for management of Cercospora leaf spot of chilli. The practices reduced the incidence by 72.82%, severity by 65.60%. The yield increased by 35.11%. Benefit cost ratio (BCR) was 3.34.J. Bangladesh Agril. Univ. 13(2): 191-196, December 2015

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Effect of Production System and Pruning on Temporal Development of Cercospora depazeoides and on Berry Yield in Black Elderberry Orchards

Plant Disease ◽

10.1094/pdis-93-6-0625 ◽

2009 ◽

Vol 93 (6) ◽

pp. 625-631 ◽

Cited By ~ 1

Author(s):

I. J. Holb ◽

J. M. Gáll ◽

B. Fodor

Keyword(s):

Leaf Spot ◽

Production Systems ◽

Disease Incidence ◽

Organic Production ◽

Integrated System ◽

Disease Development ◽

Temporal Development ◽

Cercospora Leaf Spot ◽

Organic System ◽

Disease Progress

In a 2-year study, the temporal development of Cercospora leaf spot (Cercospora depazeoides) and berry yield were evaluated in two production systems (integrated and organic) and in two winter pruning treatments (trees pruned to four and eight scaffolds) in two black elderberry (Sambucus nigra) orchards in Hungary. Under organic production, leaf spot onset occurred 2 to 4 weeks earlier (mid- and late July) in both years and both orchards compared with the integrated program. Disease then continuously progressed until the final assessment date (late September) in both years, reaching a maximum final disease incidence of 15.9% in the integrated system and of 38.2% in the organic system. In general, disease progress after late August was greater on trees pruned to eight scaffolds than on trees pruned to four scaffolds in both production systems. Both final disease incidence and area under the disease progress curves (AUDPC) were significantly lower (P < 0.001) in the integrated treatments compared with organic ones. Across all treatments, both disease measures were significantly (P < 0.05) lower on trees pruned to four scaffolds compared with trees pruned to eight scaffolds. However, when the effect of pruning on final disease incidence and AUDPC was analyzed separately for integrated and organic systems, pruning caused uniformly significant differences in disease development only for the organic system. Berry yield was significantly higher (P < 0.05) in the integrated system compared with the organic system, but pruning showed no significant effect on yield. Overall, pruning to four scaffolds resulted in consistently lower disease development in organic production compared to integrated. Thus, winter pruning may be useful as a Cercospora leaf spot management practice in organic elderberry orchards.

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Development of a Sequential Sampling Plan using Spatial Attributes of Cercospora Leaf Spot Epidemics of Table Beet in New York

Plant Disease ◽

10.1094/pdis-07-20-1619-re ◽

2021 ◽

Author(s):

Daniel Winter Heck ◽

Julie R Kikkert ◽

Linda Hanson ◽

Sarah Jane Pethybridge

Keyword(s):

New York ◽

Leaf Spot ◽

Disease Incidence ◽

Sequential Sampling ◽

Sampling Plan ◽

Classification Models ◽

Cercospora Leaf Spot ◽

Sample Number ◽

Sequential Sampling Plan ◽

True Value

Sampling strategies that effectively assess disease intensity in the field are important to underpin management decisions. To develop a sequential sampling plan for the incidence of Cercospora leaf spot (CLS), caused by Cercospora beticola, 31 table beet fields were assessed in New York. Assessments of CLS incidence were performed in six leaves arbitrarily selected in 51 sampling locations along each of the three to six linear transects per field. Spatial pattern analyses were performed, and results were used to develop sequential sampling estimation and classification models. CLS incidence (p) ranged from 0.13 to 0.92 with a median of 0.31, and beta-binomial distribution, which is reflective of aggregation, best described the spatial patterns observed. Aggregation was commonly detected (>95%) by methods using the point-process approach, runs analyses, and autocorrelation up to the fourth spatial lag. For SADIE, 45% of the datasets were classified as a random pattern. In the sequential sampling estimation and classification models, disease units are sampled until a prespecified target is achieved. For estimation, the goal was sampling CLS incidence with a preselected coefficient of variation (C). Achieving the C = 0.1 was challenging with less than 51 sampling units, and only observed on datasets with an incidence above 0.3. Reducing the level of precision, i.e. increasing C to 0.2, allowed the preselected C be achieved with a lower number of sampling units and with an estimated incidence (p̂) close to the true value of p. For classification, the goal was to classify the datasets above or below prespecified thresholds (pt) used for CLS management. The average sample number (ASN) was determined by Monte Carlo simulations, and was between 20 and 45 at disease incidence values close to pt, and approximately 11 when far from pt. Correct decisions occurred in over 76% of the validation datasets. Results indicated these sequential sampling plans can be used to effectively assess CLS incidence in table beet fields.

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Determining the Sources of Primary and Secondary Inoculum and Seasonal Inoculum Dynamics of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽

10.1094/pdis-09-18-1694-re ◽

2019 ◽

Vol 103 (5) ◽

pp. 951-958

Author(s):

Shan Lin ◽

Francesca Peduto Hand

Keyword(s):

Leaf Spot ◽

Fungal Pathogens ◽

Disease Incidence ◽

Fruit Rot ◽

Plant Production ◽

Mature Fruit ◽

Average Temperature ◽

Leaf Spots ◽

Maximum Minimum

Fruit rot of deciduous holly, caused by species of the genera Alternaria, Colletotrichum, Diaporthe, and Epicoccum, is affecting plant production in Midwestern and Eastern U.S. nurseries. To determine the sources of inoculum, dormant twigs and mummified fruit were collected, and leaf spot development was monitored throughout the season from three Ohio nurseries over two consecutive years. Mummified fruit was the main source of primary inoculum for species of Alternaria and Epicoccum, whereas mummified fruit and bark were equally important for species of Colletotrichum and Diaporthe. Brown, irregular leaf spots developed in the summer, and disease incidence and severity increased along with leaf and fruit development. Coalesced leaf spots eventually resulted in early plant defoliation. When tested for their pathogenicity on fruit, leaf spot isolates were able to infect wounded mature fruit and induce rot symptoms, which indicated that leaf spots could serve as a source of secondary inoculum for fruit infections. In addition, spore traps were used to monitor seasonal inoculum abundance in the nurseries. Fruit rot pathogens were captured by the spore traps throughout the season, with peak dissemination occurring during flowering. In this study, we also attempted to understand the role of environmental factors on leaf spot development. Although leaf spot incidence and severity were negatively correlated to mean maximum, minimum and average temperature, a decrease in temperature also coincided with leaf senescence. The role of temperature on leaf spot development should be further studied to fully interpret these results.

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Compatibility of Mancozeb 75 WP with some plant extracts in the integrated management of Cercospora leaf spot disease of okra (Abelmoschus esculentus (L.) Moench)

Ghana Journal of Agricultural Science ◽

10.4314/gjas.v55i2.3 ◽

2020 ◽

Vol 55 (2) ◽

pp. 26-38

Author(s):

V.O. Dania ◽

N. E. Sam

Keyword(s):

Leaf Spot ◽

Sandy Loam ◽

Integrated Management ◽

Disease Incidence ◽

Block Design ◽

Foliar Spray ◽

Leaf Spot Disease ◽

Syzygium Aromaticum ◽

Cercospora Leaf Spot ◽

Combined Application

The use of synthetic mancozeb fungicide has not been effective in the control of okra leaf spot (Pseudocercospora abelmoschi) disease amidst critical issues of environmental concerns. Therefore, this study evaluated the compatibility of mancozeb 75 WP with some botanicals in the integrated management of the disease. Laboratory assay was a 3×4×2 factorial laid out in a completely randomized design with three replications, while the field experiment was a randomized complete block design with 14 treatments. Four extract concentrations, 15, 30, 45 and 50% w/v and 0.5 g/l Mancozeb 75 WP were evaluated. The application of Syzygium aromaticum extract at 50% w/v concentration had the highest mycelial growth reduction of 71.89% of the pathogen. The soil textural class was sandy loam and treatments effect on okra growth indices did not differ significantly (p>0.05). The highest pod yield of 15.48 t/ha-1 was obtained in treatment inoculated with P. abelmoschi. but treated with a combination of S. aromaticum and Mancozeb. The same treatment had the lowest disease incidence of 4.01%, while combined application of C. papaya, S. aromaticum and Mancozeb recorded significantly (p<0.05) lower disease severity among inoculated plants. Therefore, this combination is recommended as foliar spray on okra in place of Mancozeb.

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The Biocontrol of Soil Transmitted Cercospora capsici with Lactobacillus plantarum

Journal of Advances in Microbiology ◽

10.9734/jamb/2019/v18i330173 ◽

2019 ◽

pp. 1-8

Author(s):

Oluwafemi M. Adedire ◽

Ayotunde Pitan ◽

Adekunle O. Farinu ◽

Wuraola F. Ogundipe

Keyword(s):

Leaf Spot ◽

Growth Parameters ◽

Control Measure ◽

Seed Priming ◽

Severity Index ◽

Leaf Spot Disease ◽

Pepper Plant ◽

Cercospora Leaf Spot ◽

Spot Disease ◽

Source Of Infection

Microbial diseases of pepper (Capsicum species) are the most significant factors contributing to the loss of this economically important vegetable crop. Leaf spot disease caused by Cercospora capsici is one of the major constraints to pepper production in Nigeria. The disease is reportedly introduced through infected seeds. However, the development of Cercospora leaf spot on plants propagated from fungicide-treated seeds suggests an alternative perennial source of infection and also necessitates the development of an efficient, safe control measure. C. capsici was isolated from infected pepper plant through the direct plating method and subsequently characterised. Treated pepper seeds (with L. plantarum) were planted in C. capsici inoculated soil, while the emergence, seedling growth parameters and severity of leaf spot were observed. The severity index of Cercospora leaf spot on pepper plants (observed at the 20th day after planting) was significantly lower on L. plantarum treated plant set (0.07) than on pepper without seed treatment. Seed emergence rate index increased from 11.11 to 15.33% /day of untreated to treated pepper seeds sown in infected soil respectively, while the mean emergence time of untreated seeds (8.32 days) was significantly higher in C. capsici infected soil. It could therefore be deduced that seed priming with L. plantarum improved the seedling vigor and resistance of pepper to leaf spot disease caused by C. capsici.

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Occurrence of Different Kinds of Diseases in Sesame Cultivation in Myanmar and Their Impact to Sesame Yield

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v38i430309 ◽

2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Yu Yu Min ◽

Koki Toyota

Keyword(s):

Powdery Mildew ◽

Leaf Spot ◽

Leaf Roll ◽

Stem Rot ◽

Yield Reduction ◽

Yield Losses ◽

Bacterial Leaf Spot ◽

Cercospora Leaf Spot ◽

Charcoal Rot ◽

Leaf Curl

We surveyed diseases of sesame in 10 farmers’ fields at Nay Pyi Taw, Myanmar and did interviews 25 farmers for the occurrence of diseases and its impact on yield in Magway, the major sesame growing area in Myanmar. We found phyllody, charcoal rot (root and stem rot), Alternaria leaf blight, powdery mildew, and leaf curl, based on on-site symptoms and their microscopic observation in Nay Pyi Taw. The disease incidence ranged from 5% to 30% in phyllody, from 10% to 30% in charcoal rot (root and stem rot) and 10% to 40% in Alternaria blight, while leaf curl and powdery mildew were not observed abundantly. According to interviews conducted in Magway, 60% of the farmers suffered from phyllody disease symptoms, 80% from charcoal rot, 48% from Cercospora, 28% bacterial leaf spot and 24% diseases with the symptoms of leaf roll. Most farmers (84%) noticed combinations of diseases symptoms either phyllody or charcoal rot/black and stem rot or Cercospora leaf spot and/or bacterial leaf spot. Yield losses ranged from 5 to 50% by phyllody, from 10 to 75% by charcoal rot (root and stem rot), from 5 to 50% by Cercospora leaf spot, and 5% by bacterial leaf spot. Other abnormal symptoms such as discoloring of root, seedling death and leaf yellowing were also observed and the yield losses ranged from 5 to 50%.There were no significance relations between the actual yield and yield losses estimated by each disease. A half of farmers (54%) burnt the crop residues after harvest, while 45% directly buried them in their fields including plant parts infected with diseases. Although there was no difference in sesame yield between these two practices, the average yield was higher by 15% in farmers with the burnt practice. Only a few farmers applied fungicides. Potential constraints to cause yield reduction and necessary actions to increase sesame yield are discussed.

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Bioefficacy of Plant Extracts to Control Cercospora Leaf Spot of Mungbean (Vigna radiata)

International Journal of Agricultural Research Innovation and Technology ◽

10.3329/ijarit.v3i1.16094 ◽

2013 ◽

Vol 3 (1) ◽

pp. 60-65 ◽

Cited By ~ 1

Author(s):

MN Uddin ◽

MA Bakr ◽

MR Islam ◽

MI Hossain ◽

A Hossain

Keyword(s):

Plant Extracts ◽

Leaf Spot ◽

Agricultural Research ◽

Disease Incidence ◽

Contributing Factors ◽

Cercospora Leaf Spot ◽

Neem Extract ◽

Neem Leaves ◽

Similar Disease ◽

Indigenous Plant

The experiment was conducted at Bangladesh Agricultural Research Institute farm, Joydebpur, Gazipur during March to July 2007 to evaluate the bioefficacy of some plant extracts in controlling Cercospora leaf spot of mungbean. Six indigenous plant species i.e. Neem leaves extract (1:4 w/v), Garlic cloves extract (1:5 w/v), Biskatali leaves extract (1:4 w/v), Alamanda leaves extract (1:6 w/v), Arjun leaves extract (1:4 w/v) and Debdaru leaves extract (1:5 w/v) were used in this experiment. The experiment was laid out in RCBD with seven treatments and four replications. Data on disease incidence, severity, yield contributing characters and yield of mungbean were recorded. Naturally, infection of the disease was considered in this experiment. The lowest disease incidence (7.33%) at 60 DAS was found in T1. Lowest and similar disease severity (PDI= 4.55) was found in T2 and T3 at the same DAS. Neem extract treated plots gave better response in yield (1.26 t ha-1) and all the yield contributing parameters like inflorescences plant-1 (13.45), tallest plant (51.44 cm), the maximum number of pods plant-1 (26.81), length of pod (8.56 cm), number of seeds pod-1 (12.64) and 1000 seeds weight (27.33 g) followed by T2 and T3. The highest disease incidence (26.50%) and disease index (13.65%) were recorded in treatment T7 at 60 DAS. Yield and all yield contributing factors were lowest in same treatment. The results of the experiment suggested that the use of neem leaves extracts are effective for minimizing Cercospora leaf spot incidence, severity and increasing yield of mungbean. Int. J. Agril. Res. Innov. & Tech. 3 (1): 60-65, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.16094

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Survey on Nigerian Castor Germplasm for Potential Resistant Genotypes to Cercospora Leaf Spot

Notulae Scientia Biologicae ◽

10.15835/nsb11310441 ◽

2019 ◽

Vol 11 (3) ◽

pp. 440-446

Author(s):

Bolaji Zuluqurineen SALIHU ◽

Mathew Omoniyi ADEBOLA ◽

Maryam Alfa KABARAINI ◽

Sunkanmi Tokunbo GBADEYAN ◽

Adijat Abolore AJADI ◽

...

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Block Design ◽

Damage Index ◽

Principal Component ◽

Average Score ◽

Economic Damage ◽

Limiting Factor ◽

Cercospora Leaf Spot ◽

Resistant Genotypes

Fungal diseases cause a lot of economic damage in castor and in some instances; it is a limiting factor to commercial cultivation of the crop. In the present study, survey on castor germplasm for sources of resistant genes to Cercospora leaf spot was carried out at National Cereals Research Institute Badeggi, Nigeria. The genotypes were grown in a resolvable incomplete block design with three replications. The results obtained revealed high variability of host resistance among the genotypes. Percentage disease incidence ranged between 16.67% and 100%. A range between 1.43 score and 4.17 scores with average score of 2.89 were recorded for disease severity among the genotypes. Highest (95.92%) and lowest (13.03%) damage index were observed in the genotypes Acc. 059 and Acc. 022 respectively. The Principal component (PC) 1 to 4 explained 100% of the variability in the germplasm. PC1 explained 69.72% of the variability with the major contributory parameters being the disease incidence, severity and damage index. Significant negative correlations were recorded between the seed yield and all the three disease indices. The result of cluster analysis revealed six cluster groups among the germplasm with cluster membership ranging between 4 and 40 members. The cluster I contained members (Acc. 002, Acc. 017, Acc. 022, Acc. 026, Acc. 027, Acc. 048 and Acc. 061) with low average disease incidence, severity and damage index. The results reported here could serve as a basis for further screening of the potential resistant genotypes under controlled condition to develop resistant lines.

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First Report of Botrytis cinerea Causing Leaf Spot on Strawberry in Florida

Plant Disease ◽

10.1094/pdis-05-21-1082-pdn ◽

2021 ◽

Author(s):

Marcus Vinicius Marin ◽

Natalia A. Peres

Keyword(s):

Botrytis Cinerea ◽

Leaf Spot ◽

Fungicide Resistance ◽

Disease Incidence ◽

Deionized Water ◽

Fruit Rot ◽

Tween 20 ◽

Isolation Medium ◽

First Report ◽

Leaf Spots

During the 2020-2021 Florida strawberry season (October to April), strawberry (Fragaria × ananassa) plants showing leaf spots were observed on samples submitted to the Diagnostic Clinic at the University of Florida’s Gulf Coast Research and Education Center. Disease incidence was up to 5% and observed on four different farms in Plant City, FL on cultivars SensationTM Florida127 and Florida Brilliance. All the samples were submitted early in the season (November) and shared the same nursery source in California. Symptoms consisted of circular or irregular lesions with purple or brown halos, eventually developing leaf blight with sporulation at the center on advanced lesions. Diseased tissues (0.5 mm2) were surface disinfested with 10% bleach solution for 90 s, rinsed twice in sterile deionized water, and plated on general isolation medium (Amiri et al. 2018). Plates were incubated at 25°C and a 12-h photoperiod. A fungus producing white mycelia with sparse sporulation of Botrytis-like spores was consistently isolated. Isolates were single-spored and grown on HA medium to induce sporulation (Leroch et al. 2013). Three isolates (20-291, 20-293, and 20-295) were selected for identification and pathogenicity assays. Resulting cultures on HA had profuse sporulation resembling gray mold. Conidia (n=50) were round to ellipsoid ranging from 9 to 14.6 μm long (Avg=10.8, SD=1.3) and 6.3 to 9.5 μm wide (Avg=7.7, Sd=0.7). No sclerotia formation was observed on GI and HA medium. Based on morphology, the pathogen was tentatively identified as Botrytis cinerea (Hong et al. 2001; Jarvis 1977). DNA was extracted from the same three isolates using the FastDNA kit (MP Biomedicals, Solon, OH), and the heat shock protein (HSP60), RNA polymerase II-binding (RPB2), and glyceraldehyde 3-phosphate dehydrogenase (G3PDH) genes were amplified (Staats et al. 2004). Sequences were deposited in GenBank (accession nos. MZ288746 - MZ288754). BLASTn searches revealed that isolates were 100% identical to B. cinerea reported causing leaf spot on strawberry in California; accession numbers MK919494 (HSP60, 996/996 bp), MK919495 (RPB2, 1131/1131 bp), and MK919496 (G3PDH, 877/877 bp). To test for pathogenicity, four one-month-old plants of 'Florida Brilliance' were used per isolate and control treatment. Spores were harvested from two-week-old cultures grown on HA medium, and the suspension adjusted to 106 spores/mL in a solution of 0.1% of Tween 20. Plants were spray inoculated until run-off and kept inside clear plastic boxes for 48 h. Control plants were sprayed with sterile deionized water. Afterward, plants were kept in a misting table in the greenhouse with a water regime of 3 s every 10 min during the day. Disease incidence was evaluated weekly, and the experiment repeated once. Two weeks after inoculation, leaf spots were observed in all inoculated plants, while controls remained healthy. Fungi morphologically identical to the original isolates were re-isolated from the diseased tissues. To our knowledge, this is the first report of B. cinerea causing leaf spot on strawberry in Florida. This disease was recently reported in California (Mansouripour and Holmes 2020), which is where the transplants originated from. Considering the disease was observed early in the Florida season, it is likely that it was introduced with transplants from the nursery. This pathogen is also the causal agent of Botrytis fruit rot, which is considered a major disease of strawberry, and a previous study has shown that populations resistant to multiple fungicides are introduced with transplants (Mertely et al. 2018, Oliveira et al. 2018). While Botrytis leaf spot is currently considered rare and of minor significance (Mansouripour and Holmes 2020), it could contribute to the spread of fungicide resistance to from nursery to strawberry fruit production fields. Efforts should be implemented to monitor its occurrence and spread considering the high variability and fungicide resistance profile of this pathogen.

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