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 First Report of Alternaria Leaf Spot of Almond Caused by Species in the Alternaria alternata Complex in California

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 558-558 ◽  
Author(s):  
B. L. Teviotdale ◽  
M. Viveros ◽  
B. Pryor ◽  
J. E. Adaskaveg
Keyword(s):  
Alternaria Alternata ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Prunus Dulcis ◽  
Leaf Spot Disease ◽  
Yield Losses ◽  
Mature Leaves ◽  
Branching Chains ◽  
Paper Towels ◽  
Industry Conference

A new leaf spot disease of almond (Prunus dulcis [Mill.] D. Webb) was observed in California in the late 1980s and was first associated with severe defoliation in the mid-1990s (1). Orchards in areas with frequent summer dews, high humidity, and little air movement sustained severe defoliation, resulting in yield losses often exceeding 50%. Symptoms occur only on leaf blades in late spring and summer. Lesions develop as small, circular, tan spots 1 to 3 mm in diameter that may enlarge to 5 to 20 mm in size. Semicircular lesions frequently develop along the leaf margins and tips. The centers of mature lesions become black with fungal sporulation. The fungi isolated from the margins of sporulating and non-sporulating lesions were identified as three species in the Alternaria alternata complex: A. alternata, A. arborescens, and A. tenuissima (2,3). Cultures grown in the dark on potato dextrose (PDA) or potato-carrot agar are grayish white to olivacious green in the former two species and dark gray and wooly in the latter species. On 5% PDA, cultures of all three species produced catenulate dictyospores that were granular to punctate (-verrucose), pale yellowish to brown or black, and had visible apical and basal pores. Conidial morphology depended on chain position; apical conidia ranged from ovoid to ellipsoid, whereas basal conidia were elliptical to obclavate. Average conidial dimensions of A. alternata and A. arborescens ranged from 20 to 28 × 8 to 10 μm. Conidia of A. alternata were produced in acropetal succession in branching chains on single, short suberect conidiophores. A. arborescens produced conidia similarly but mostly in dichotomously branching chains on short to long conidiophores. Average conidial dimensions of A. tenuissima ranged from 20 to 34 × 8 to 12 μm and they were produced in simple chains with one or two branches forming occasionally. In preliminary studies, the optimum temperature for mycelial growth on PDA for all three species ranged from 24 to 28°C. Fifty mature leaves on each of four 7- or 8-year-old almond cv. Butte trees were inoculated at 2- to 3-week intervals from mid-spring through summer in 1999 and 2000. Leaves were sprayed with aqueous suspensions containing 105 conidia per milliliter for one isolate each of A. alternata and A. arborescens and two isolates of A. tenuissima or with sterile distilled water. The shoots were covered for 72 h with plastic-lined brown paper bags containing wet paper towels. Leaves were examined for infection after 7 and 14 days. All isolates were pathogenic and produced non-sporulating lesions similar to those observed in natural infections. No symptoms were observed on noninoculated control plants. Disease incidence was low (<15%) until late June 1999 and July 2000. Inoculations in summer produced increasingly more infections, reaching incidences of 40 to 52% in September 1999 and 18 to 80% in August 2000. References: (1) J. E. Adaskaveg. 1994. Pages 5–7 in Proceedings of the 22nd Annual Almond Industry Conference. 1994. (2) J. Rotem. 1994. The genus Alternaria. Biology, Epidemiology, and Pathogenicity. APS Press, St. Paul, MN. (3) E. G. Simmons. Mycotaxon 70:325–369, 1999.

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

In-Vitro Efficacy of Different Fungicides Against Leaf Spot of Marigold Caused by Alternaria alternata

2021 ◽  
Vol 1 (1) ◽  
pp. 1-4
Author(s):  
Keyword(s):  
Lower Limit ◽  
Alternaria Alternata ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Colony Growth ◽  
Good Effect ◽  
Upper Limit ◽  
Disease Occurrence ◽  
Chemical Fungicides

This study was carried out to study the in-vitro efficacy of different chemical fungicides leaf spot of marigold, caused by Alternaria alternata. The results of present study showed that the disease incidence from various locations of district Hyderabad Sindh was observed Ghangra Mori 35%, TandoHyder 30%, Rahooki 25%, Moosa Khatyan20%, and Hosri 15%. Upper limit disease occurrence was observed from Ghangra Mori and lower limit sickness was recorded from Hosri. The chemical fungicide Nativo observed 43%, 25.5% and 18.5% linear colony growth of Alternaria alternata at 100, 200 and 400 ppm, respectively. Aliete observed 52, 31.5 and 21 respectively. Carbandazm observed 52.5, 29.5 and 21mm respectively and Mancozeb observed 51, 28.5 and 20mm respectively. Lower limit growth of Alternaria alternata were judge in 400 ppm instead Nativo pursuited by Mancozeb, Carbandazm and Aliete, separately. In control there was 90mm was recorded. It was concluded that chemical fungicide ‘Nativo’ were full effective to stop the disperssion of Alternaria alternata in 400 ppm. Anytime the plant infusion, Neem infusion show good effect opposite linear colony growth of Alternaria alternata on 6% solution

Seasonal variation in lucerne foliar diseases and cultivar reaction to leaf spot pathogens in the field in southern Queensland

1993 ◽  
Vol 33 (3) ◽  
pp. 343 ◽  
Author(s):  
MJ Inch ◽  
JAG Irwin ◽  
RA Bray
Keyword(s):  
Seasonal Variation ◽  
Genetic Variability ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Breeding Line ◽  
Disease Reaction ◽  
Foliar Diseases ◽  
Foliar Pathogens ◽  
Major Pathogens

Detailed assessments were made of leaf and stem disease incidence and severity on 16 lucerne cultivars and lines over 10 months in the field near Gatton, Queensland (27�34'S., 152�17'E.). The 4 major pathogens encountered were Leptosphaerulina trifolii, Uromyces striatus, Pseudopeziza medicaginis, and Cercospora medicaginis. The diseases caused by these pathogens showed a seasonality in occurrence. Both U. striatus and P. medicaginis were more severe on older shoots, whereas L. trifolii caused highest disease levels on shoots sampled 2 weeks after cutting. The relative rankings of the lucerne entries changed across pathogens, but breeding line MSA showed the best resistance to rust, L. trifolii, and P. medicaginis. This work has indicated that there is genetic variability in disease reaction to foliar pathogens which could be exploited in the development of cultivars for subtropical Queensland.

scholarly journals Avances en la selección de fuentes de resistencia a las principales enfermedades del frijol común (Phaseolus vulgaris L.) en Costa Rica.

2006 ◽  
Vol 11 (2) ◽  
pp. 25 ◽  
Author(s):  
Carlos M. Araya ◽  
Rodolfo Araya
Keyword(s):  
Leaf Spot ◽  
Core Collection ◽  
Breeding Program ◽  
Colletotrichum Lindemuthianum ◽  
Angular Leaf Spot ◽  
Phaseolus Vulgaris L ◽  
Sources Of Resistance ◽  
Disease Reaction ◽  
Growing Seasons ◽  
Experimental Plots

In this research a broad set of bean genotypes were evaluated in the search for sources of resistance to both, anthracnose (Colletotrichum lindemuthianum) and angular leaf spot (Pahaeoisriopsis griseola). The germplasm evaluated came from the National Bean Breeding Program and international nurseries from CIAT: VIFURE, VIPADOGEN and CORE COLLECTION. Experimental plots were establised in Puriscal (1017 masl), Alajuela (814 masl) and Fraijanes (1650 masl), during the 97-98 and 98-99 growing seasons. Experimental plots were single or two rows from two to six m in length depending on seed availability. Disease reaction was scored at six and eight weeks after seeding using a 1 to 9 severity scale. Only genotypes showing 1-3 disease reaction for anthracnose and 1-4 for angular leaf spot were selected. In the germplas from the National Bean Breeding Program nine lines resistant to both pathogens were identified, of those, five lines were specifically resistant to anthracnose and two angular leaf spot. In the VIPADOGEN from CIAT, 25 lines were resistant to anthracnose and only two were resistant to both diseases. These materials also displayed adaptation to either drought or low soil fertility. The CORE COLLECTION nursery provided 82 lines resistant to anthracnose, 12 lines resistant to angular leaf spot and 26 lines were resistant to both pathogens. The most outstanding sources of resistance to anthracnose and angular leaf spot will be made available in a regional nursery.

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

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.

scholarly journals Effect of fungicide on disease incidence and yield of bean (Phaseolus vulgaris L.) infected with Isariopsis griseola Sacc. and Ascochyta phaseolorum Sacc.

1969 ◽  
pp. 127-134
Author(s):  
Rocío Rodríguez ◽  
Pedro L. Meléndez
Keyword(s):  
Phaseolus Vulgaris ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Angular Leaf Spot ◽  
Leaf Spot Disease ◽  
Phaseolus Vulgaris L ◽  
Foliar Diseases ◽  
Spot Disease

Two foliar diseases of beans, Phaseolus vulgaris L., namely angular leaf spot and ascochyta leaf spot, caused by Isariopsis griseola and Ascochyta phaseolorum, respectively, were effectively controlled with chemicals. Biweekly applications of mancozeb and chlorothalonil (1.12, 2.48 and 4.48 kg/ ha) effectively protected the foliage of bean cultivars Bonita and Naranjito against attacks by both pathogens. Cultivar Bonita responded better to treatments than cv. Naranjito in terms of yield. Some dosages of mancozeb and chlorothalonil increased yield of cv. Bonita affected by angular leaf spot. Yield increases in plots treated with benomyl increased only when the highest rate of this chemical was used. Even at the lowest dosages, the three chemicals tested increased yield in cv. Bonita affected by the ascochyta leaf spot disease.

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