The bioactivity and efficacy of benzovindiflupyr against Corynespora cassiicola, the causal agent of cucumber Corynespora leaf spot

Plant Disease ◽  
2021 ◽  
Author(s):  
Jiamei Zhu ◽  
Xiuhuan Li ◽  
Lingyan Zhang ◽  
Yangyang Gao ◽  
Wei Mu ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Integrated Management ◽  
Disease Incidence ◽  
Field Trials ◽  
Corynespora Cassiicola ◽  
Atp Production ◽  
Control Failure ◽  
Efficient Alternative ◽  
The Mean ◽  
And Control

Corynespora cassiicola, which causes Corynespora leaf spot, results in considerable yield loss of cucumber grown in greenhouses. Frequent reports of reduced efficacy and control failure of fungicides warrant new, efficient alternative chemistries. In the present study, the sensitivity of C. cassiicola to benzovindiflupyr was evaluated using a collection of 81 isolates collected from Shandong, China. The mean EC50 values for mycelial growth, spore germination and germ tube elongation of C. cassiicola were 0.69 ± 0.44, 0.12 ± 0.063 and 0.13 ± 0.076 µg mL-1, respectively. Benzovindiflupyr treatment led to a reduced respiration rate and ATP production of C. cassiicola and decreased spore pathogenicity by 21.9% on average. Additionally, detached cucumber leaves sprayed with fungicides before or after inoculation were used to assess the efficacy of benzovindiflupyr against C. cassiicola. Benzovindiflupyr (150 µg mL-1) exhibited preventive and curative efficacies of 86.9% and 77.1%, respectively. Benzovindiflupyr at 150 g a.i. ha-1 provided over 70% efficacy in field trials performed in 2018 and 2019, which was significantly higher than that of the reference fungicides fluopyram and fluxapyroxad at the same dose. Furthermore, the yield of commercial cucumber increased as disease incidence decreased. Our findings pave the way for the introduction of benzovindiflupyr in the integrated management of Corynespora leaf spot.

scholarly journals In-Furrow Applications of Metalaxyl and Phosphite for Control of Pink Rot (Phytophthora erythroseptica) of Potato in New Brunswick, Canada

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Khalil I. Al-Mughrabi ◽  
Rick D. Peters ◽  
H. W. (Bud) Platt ◽  
Gilles Moreau ◽  
Appanna Vikram ◽  
...  
Keyword(s):  
New Brunswick ◽  
Disease Incidence ◽  
Field Trials ◽  
Russet Burbank ◽  
Viable Option ◽  
Potato Plants ◽  
Pink Rot ◽  
Phytophthora Erythroseptica ◽  
Sensitive Isolate ◽  
The Mean

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.

scholarly journals Screening of French Bean (Phaseolus vulgaris L.) Genotypes against Alternaria Leaf Spot Caused by (Alternaria alternata) under Dryland Conditions of Kashmir

2021 ◽  
pp. 25-30
Author(s):  
Sabiya Bashir ◽  
Mohammad Najeeb Mughal ◽  
Zahida Rashid ◽  
Shabeena Majid ◽  
Sabeena Naseer ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Disease Incidence ◽  
French Bean ◽  
Phaseolus Vulgaris L ◽  
Dryland Agriculture ◽  
Disease Reaction ◽  
The Mean ◽  
Selection For ◽  
Resistant Genotypes

Sixty-three genotypes of  french bean was screened against leaf spot (Alternaria  alternata) in sick plots at Research Farm of Dryland Agriculture Research Srinagar, Rangreth during  Kharif  2018 and 2019. The highest mean disease incidence ranged from 0.00 to 85.00 per cent  with  the mean disease intensity ranged from 0.00 to 53.26 per cent .One genotype namely  ‘Local Pulwama’ was highly susceptible in their disease reaction. Among the screened germplasm, ‘Highly Resistant’ genotypes was SKU-R-601, SKUA-R-105, SKU-R-927, DARS-25, DARS-66, DARS-R-615,  while as ‘Susceptible’ genotypes was  DARS-8, DARS-12,  DARS-11, SKUAST-R-155, SKU-R-928, DARS-7, DARS-R-4, Bhaderwah (L),  Local  Kupwara black and Raj Jawala. Local Pulwama was found to be a highly susceptible (HS) genotype.  Twenty nine genotypes namely., DARS-16, DARS-9, DARS-54, DARS-39, VL-125, DARS-63, ENTO-504, SKUAST-204,SKU-R-925, DARS-60, DARS-109, DARS-43, DARS-44, SKU-R-23, DARS-4, DARS-74, SKU-R-105, DARS-40, DARS-23, DARS-18, SKU-R-71, WB-341, SKU-R-605, Uri local, Shopian (L), SKU-R-23, DARS-71, SSGB-729, DARS-R-19 showed resistant reaction to disease. The selection for resistance was based on the reaction of varieties on leaves.

scholarly journals Oral Administration of Lactobacillus Strains Isolated from Breast Milk as an Alternative for the Treatment of Infectious Mastitis during Lactation

2008 ◽  
Vol 74 (15) ◽  
pp. 4650-4655 ◽  
Author(s):  
E. Jiménez ◽  
L. Fernández ◽  
A. Maldonado ◽  
R. Martín ◽  
M. Olivares ◽  
...  
Keyword(s):  
Breast Milk ◽  
Clinical Signs ◽  
Control Group ◽  
Control Groups ◽  
Lactobacillus Salivarius ◽  
Probiotic Group ◽  
Efficient Alternative ◽  
The Mean ◽  
And Control ◽  
Infectious Mastitis

ABSTRACT In this study, 20 women with staphylococcal mastitis were randomly divided in two groups. Those in the probiotic group daily ingested 10 log10 CFU of Lactobacillus salivarius CECT5713 and the same quantity of Lactobacillus gasseri CECT5714 for 4 weeks, while those in the control one only ingested the excipient. Both lactobacillus strains were originally isolated from breast milk. On day 0, the mean staphylococcal counts in the probiotic and control groups were similar (4.74 and 4.81 log10 CFU/ml, respectively), but lactobacilli could not be detected. On day 30, the mean staphylococcal count in the probiotic group (2.96 log10 CFU/ml) was lower than that of the control group (4.79 log10 CFU/ml). L. salivarius CECT5713 and L. gasseri CECT5714 were isolated from the milk samples of 6 of the 10 women of the probiotic group. At day 14, no clinical signs of mastitis were observed in the women assigned to the probiotic group, but mastitis persisted throughout the study period in the control group women. In conclusion, L. salivarius CECT5713 and L. gasseri CECT5714 appear to be an efficient alternative for the treatment of lactational infectious mastitis during lactation.

Assessing resistance to spring black stem and leaf spot of alfalfa caused by Phoma spp.

2004 ◽  
Vol 84 (1) ◽  
pp. 311-317 ◽  
Author(s):  
H. Wang ◽  
S. F. Hwang ◽  
K. F. Chang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Leaf Spot ◽  
Similar Pattern ◽  
Disease Incidence ◽  
Field Trials ◽  
Disease Reaction ◽  
Detached Leaf ◽  
Controlled Conditions ◽  
Detached Leaves ◽  
Phoma Sclerotioides

The disease reaction of alfalfa (Medicago sativa) cultivars to spring black stem was evaluated in field trials and greenhouse experiments. In field trials, differences in cultivar reaction to leaf spot (predominantly spring black stem) were observed in 9 of 16 station years. The reaction of certain cultivars was consistent across most trials, but other cultivars were quite variable. Under controlled conditions, one isolate each of Phoma sclerotioides and P. exigua produced symptoms on alfalfa leaves that were similar to those caused by P. medicaginis. These results indicate that P. medicaginis is not the only pathogen responsible for symptoms of spring black stem on alfalfa in the prairie region. In a detached-leaf study, one isolate each of P. medicaginis, P. sclerotioides and P. exigua produced leaf lesions on all 18 alfalfa cultivars assessed. Disease incidence in Absolute, Algonquin, Pickseed 3006 and Anik (M. sativa subsp. falcata) was lower than in 630 and AC Blue J. Inoculation of eight selected cultivars using a range of spore concentrations under controlled conditions showed a similar pattern; all three isolates produced leaf lesions on all eight cultivars. Ino culation with conidial suspensions of P. medicaginis resulted in a lower disease incidence on Absolute than on Beaver. Key words: Medicago sativa, Medicago sativa subsp. falcata, Phoma medicaginis, P. sclerotioides, P. exigua, detached leaves.

scholarly journals Sources of variation in a field evaluation of the incidence and severity of olive leaf spot

2005 ◽  
Vol 58 ◽  
pp. 273-277 ◽  
Author(s):  
E.O. Obanor ◽  
M. Walter ◽  
E.E. Jones ◽  
M.V. Jaspers
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Field Evaluation ◽  
Leaf Spot Disease ◽  
Olive Leaf ◽  
Mean Values ◽  
Spot Disease ◽  
Sources Of Variation ◽  
The Mean ◽  
Over Time

Incidence ( infected leaves) and severity (number of lesions/leaf) of olive leaf spot disease caused by Spilocaea oleagina were assessed every 2 weeks on 20 trees in a Canterbury olive grove for 12 weeks during summer 2003/04 All the trees were infected by olive leaf spot disease (OLS) and although disease incidence and severity varied between trees (Plt;0001) it did not vary between branches over time (P0088) There was a strong correlation (R20869) between disease incidence and severity It was estimated that at least five trees and 50 leaves/tree were required to correctly estimate the mean values of the parameters measured Throughout the duration of the experiment no new leaf lesions formed and although old lesions increased in size (Plt;0001) spore numbers decreased from 5104 to 1102 conidia/cm2 of lesion and viability of conidia declined from 55 to 10

Dark leaf spot (Alternaria brassicicola) on Chinese cabbage: temporal spread and its influencing factors

2002 ◽  
Vol 53 (10) ◽  
pp. 1095 ◽  
Author(s):  
L. Y. Chen ◽  
T. V. Price
Keyword(s):  
Chinese Cabbage ◽  
Wind Direction ◽  
Leaf Spot ◽  
Irrigation System ◽  
Disease Incidence ◽  
Field Trials ◽  
Alternaria Brassicicola ◽  
Disease Spread ◽  
Average Wind ◽  
Temporal Spread

Temporal spread of dark leaf spot on Chinese cabbage was studied in experimental plots for 2 years. The effect of row orientation, the orientation of inoculated plants, and irrigation system on disease incidence and the effect of average wind direction on disease spread were investigated. A line source of inoculum in each plot was used for the 1993–94 summer and the 1994 spring–summer field trials, and 3 line sources for a 1995 autumn field trial. Disease progressed more rapidly in the 1993–94 summer than in the 1995 autumn. Disease epidemic did not develop in the 1994 spring–summer when environmental conditions were unfavourable. Disease incidence was higher in plots with row orientation parallel to the average wind direction than in plots with row orientation at right angles to the average wind direction for both the 1993–94 summer and the 1995 autumn trials. In summer 1993–94, across-row inoculation resulted in higher disease incidence than row inoculation did. No difference in disease incidence occurred between channel irrigation and overhead irrigation plots. Secondary infections always occurred adjacent to the source of inoculum and disease spread was influenced by the prevalent wind direction.

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

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.

Dark leaf spot (Alternaria brassicicola) on Chinese cabbage: spatial patterns

2005 ◽  
Vol 56 (7) ◽  
pp. 699 ◽  
Author(s):  
L. Y. Chen ◽  
T. V. Price ◽  
M. J. Silvapulle
Keyword(s):  
Chinese Cabbage ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Field Trials ◽  
Alternaria Brassicicola ◽  
Disease Spread ◽  
Distance Class ◽  
Maximum Information ◽  
Spatial Spread ◽  
Core Cluster

The spatial spread of dark leaf spot caused by Alternaria brassicicola on Chinese cabbage was characterised over 2 years. The study was conducted in 2 field trials using ordinary runs, mapping, spatial autocorrelation, and 2-dimensional distance class analyses. Diseased plants were generally clustered and cluster orientation coincided with the line of inoculation. Disease spread was greater within than across rows. The maximum number of spatial lags with significantly positive autocorrelations occurred when disease incidence levels reached 20–80% in summer 1993–94. Core cluster size generally increased with disease incidence. Two-dimensional distance class analysis was the best analytical method among those used in describing spatial spread of the disease as it did not only provide maximum information but also considered missing data.

scholarly journals Evaluation of a Disease Warning System for Phomopsis Cane and Leaf Spot of Grape: A Field Study

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1239-1246 ◽  
Author(s):  
M. Nita ◽  
M. A. Ellis ◽  
L. L. Wilson ◽  
L. V. Madden
Keyword(s):  
Leaf Spot ◽  
Shoot Growth ◽  
Disease Incidence ◽  
Warning System ◽  
Field Evaluation ◽  
Weather Conditions ◽  
Relative Difference ◽  
Phomopsis Viticola ◽  
The Mean ◽  
Vitis Spp

A field evaluation of a warning system for Phomopsis cane and leaf spot of grape (Vitis spp.), caused by Phomopsis viticola, was conducted in Ohio over 3 years (2002 to 2004) by applying fungicides and fungicide-adjuvant combinations based on predicted infection events. Three different criteria for risk—light, moderate, and high—were evaluated with the warning system. The warning system is based on measured weather conditions (temperature and wetness duration following rain) and a model for risk of leaf and internode infection. Vines were sprayed with fungicides based on either the warning system or a calendar-based 7-day protectant program, from 2.5-cm shoot growth (Eichhorn-Lorenz [E-L] stage 7) to the end of the broom (E-L stage 27). Fungicides were tested with or without an adjuvant (JMS Stylet-Oil or Regulaid). In the controls, the mean percentage of leaves and internodes with infections ranged from 36 to 100%, the number of lesions per leaf ranged from 1 to 28, and percentage of internodes covered by lesions ranged from 1 to 12%. Both the calendar-based protectant treatment (based on use of mancozeb) and the warning system treatment based on spraying in response to light or moderate predicted infection events (especially with mancozeb + Regulaid) resulted in significantly less disease incidence and severity compared with the controls. The mean percent control (relative difference in disease between a treatment and the control) was higher for the protectant schedule (˜55% and ˜80% for incidence and severity, respectively, based on application of mancozeb) than for the warning system (˜36% and ˜60% for incidence and severity, respectively, based on application of mancozeb + Regulaid), but there were two to three times more fungicide applications with the protectant schedule than with the warning system.

scholarly journals An Outbreak of Leaf Spot Caused by Corynespora cassiicola on Korean Raspberry in Korea

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 762-762 ◽  
Author(s):  
J.-H. Kwon ◽  
D.-W. Kang ◽  
Y.-S. Kwak ◽  
J. Kim
Keyword(s):  
New York ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Its Region ◽  
Pathogenic Fungi ◽  
Corynespora Cassiicola ◽  
Leaf Spots ◽  
Causal Pathogen ◽  
Recent Occurrence

In September and October 2010, leaf spots were observed on Korean raspberry (Rubus crataegifolius Bunge) plants in farmers' fields in Hapcheon, Gyeongnam Province, South Korea. Disease incidence ranged from 50 to 80% among fields. Circular- to irregular-shaped spots surrounded by yellow halos occurred frequently on the leaves of Korean raspberry plants. Brown spots became dark with wavy borders and ranged from 20 to 300 mm in diameter. Infected leaves became chlorotic, blighted, and eventually died. Fungal hyphae covered the lesions with abundant conidia and conidiophores. Fresh leaf specimens were collected from infected plants and the putative causal pathogen was isolated onto potato dextrose agar (PDA). A total of 30 isolates of the fungus were collected from diseased plants collected in the field. Fungal colonies were gray to brown on PDA. Colonies formed conidia, 38 to 210 × 8 to 20 μm, which were solitary or catenary, obclavate to cylindrical, smooth, straight or curved, and subhyaline to pale brown or brown. Conidiophores, 98 to 840 × 4 to 12 μm, were slightly or conspicuously swollen at apex, single, simple, straight or slightly flexuous, pale to midbrown, smooth, septate, thick, monotretic, and determinate or in tufts. Morphological characteristics of the fungal specimens were similar to descriptions of Corynespora cassiicola (1). A representative isolate of the pathogen was used to inoculate leaves of Korean raspberry plants for pathogenicity testing. Five leaves of a 3-month-old potted plant were sprayed with a suspension of conidia in water. Conidia were harvested from PDA cultures and adjusted to 2 × 104 conidia/ml with a hemocytometer. Five leaves sprayed with sterile distilled water served as controls. Inoculated plants were placed in a humid chamber with 100% relative humidity at 30°C for 24 h and then moved to a greenhouse. Symptoms similar to those observed in the farmers' fields developed on the inoculated leaves within 12 days, whereas the controls remained asymptomatic. The causal fungus was reisolated from the lesions of inoculated plants to satisfy Koch's postulates. To confirm the identity of the fungus, the complete internal transcribed spacer (ITS) rDNA region was amplified and sequenced (3). Amplification of the ITS region generated a 559-bp sequence (GenBank Accession No. JQ340026) with 100% similarity to sequences of C. cassiicola in GenBank (Accession No. GU138988) causing leaf spot on cassava (2). Based on the symptoms, morphological characteristics, pathogenicity, and molecular identification, this fungus was identified as C. cassiicola (1). To our knowledge, this is the first report of leaf spot caused by C. cassiicola on Korean raspberry. The recent occurrence of leaf spot on Korean raspberry suggests that C. cassiicola is spreading widely and posing a serious threat to these plants in Korea. References: (1) M. B. Ellis et al. No. 303 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Surrey, Kew, UK, 1971. (2) X.-B. Liu et al. Plant Dis. 94:916, 2010. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, Inc., New York, 1990.

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