scholarly journals Evaluation of Essential Oils and Their Components for Broad-Spectrum Antifungal Activity and Control of Late Leaf Spot and Crown Rot Diseases in Peanut

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 375-379 ◽  
Author(s):  
G. Krishna Kishore ◽  
S. Pande ◽  
S. Harish
Keyword(s):  
Leaf Spot ◽  
Foliar Spray ◽  
Crown Rot ◽  
Curvularia Lunata ◽  
Infested Soil ◽  
Clove Oil ◽  
Cercospora Arachidicola ◽  
Cinnamon Oil ◽  
Late Leaf Spot

Clove oil, cinnamon oil, and five essential oil components (citral, eugenol, geraniol, limonene, and linalool) were tested for growth inhibition of 14 phytopathogenic fungi. Citral completely inhibited the growth of Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme, F. pallidoroseum, and Phoma sorghina in paper disc agar diffusion assays. Cinnamon oil, citral, and clove oil as low as 0.01% (vol/vol) inhibited the spore germination of Cercospora arachidicola, Phaeoisariopsis personata, and Puccinia arachidis by >90% in vitro. Limonene and linalool were observed to be the least antifungal against the test fungi and were not used in further studies. Clove oil (1% vol/vol) applied as a foliar spray 10 min before Phaeoisariopsis personata inoculation reduced the severity of late leaf spot of peanut up to 58% when challenge inoculated with 104 conidia ml-1. This treatment was more effective (P = 0.01) than 0.5% (vol/vol) citral, cinnamon oil, or clove oil and 1% (vol/vol) eugenol or geraniol. Seed treatment with the test compounds had no effect on the incidence of crown rot in peanut in Aspergillus niger-infested soil. However, soil amendment with 0.25% (vol/wt) clove oil and cinnamon oil reduced the preemergence rotting by 71 and 67% and postemergence wilting by 58 and 55%, respectively, compared with the nontreated control. These two treatments were more effective (P < 0.01) than geraniol on preemergence rotting, and more effective than citral, eugenol, and geraniol on postemergence wilting. All treatments significantly outperformed the nontreated control but none were as effective as thiram treatment.

scholarly journals Biological Control of Late Leaf Spot of Peanut (Arachis hypogaea) with Chitinolytic Bacteria

2005 ◽  
Vol 95 (10) ◽  
pp. 1157-1165 ◽  
Author(s):  
G. Krishna Kishore ◽  
Suresh Pande ◽  
A. R. Podile
Keyword(s):  
Biological Control ◽  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Specific Activity ◽  
Gel Filtration ◽  
Foliar Spray ◽  
Bacterial Cells ◽  
Late Leaf Spot ◽  
Chitinolytic Bacteria

Late leaf spot (LLS), caused by Phaeoisariopsis personata, is a foliar disease of groundnut or peanut (Arachis hypogaea) with high economic and global importance. Antifungal and chitinolytic Bacillus circulans GRS 243 and Serratia marcescens GPS 5, selected among a collection of 393 peanut-associated bacteria, were applied as a prophylactic foliar spray and tested for control of LLS. Chitin-supplemented application of B. circulans GRS 243 and S. marcescens GPS 5 resulted in improved biological control of LLS disease. Supplementation of bacterial cells with 1% (wt/vol) colloidal chitin reduced lesion frequency by 60% compared with application of bacterial cells alone, in the greenhouse. Chitinsupplemented application of GRS 243 and GPS 5 also resulted in improved and stable control of LLS in a repeated field experiment and increased the pod yields by 62 and 75%, respectively, compared with the control. Chitin-supplemented application of GPS 5 was tested in six onfarm trials, and the increase in pod yields was up to 48% in kharif (rainy season). A 55-kDa chitinase was purified from the cell-free culture filtrate of GPS 5 by affinity chromatography and gel filtration. Purified chitinase of S. marcescens GPS 5 (specific activity 120 units) inhibited the in vitro germination of P. personata conidia, lysed the conidia, and effectively controlled LLS in greenhouse tests, indicating the importance of chitinolysis in biological control of LLS disease by GPS 5.

scholarly journals Late Leaf Spot Severity and Yield of New Peanut Breeding Lines and Cultivars Grown Without Fungicides

Plant Disease ◽  
2017 ◽  
Vol 101 (11) ◽  
pp. 1843-1850 ◽  
Author(s):  
Brian S. Jordan ◽  
Albert K. Culbreath ◽  
Timothy B. Brenneman ◽  
Robert C. Kemerait ◽  
William D. Branch
Keyword(s):  
Leaf Spot ◽  
Vegetation Index ◽  
Field Experiments ◽  
Organic Production ◽  
Canopy Reflectance ◽  
Cercospora Arachidicola ◽  
Early Season ◽  
Late Leaf Spot ◽  
Breeding Lines ◽  
Width Measurements

Peanut (Arachis hypogaea) cultivars with resistance or tolerance to Cercospora arachidicola and/or Cercosporidium personatum, the causes of early and late leaf spot, respectively, are needed for organic production in the southeastern U.S. To determine the potential of new breeding lines for use in such production systems, field experiments were conducted in Tifton, GA, in 2014 and 2015 in which nine breeding lines and two cultivars, Georgia-06G and Georgia-12Y, were grown without foliar fungicide applications. In one set of trials, cultivar Georgia-12Y and most of the breeding lines evaluated had early season vigor ratings, early-season canopy width measurements, final plant populations, and pod yield that were greater than those of standard cultivar Georgia-06G. In those trials, final late leaf spot Florida scale ratings were lower and canopy reflectance measured as the normalized difference vegetation index (NDVI), was higher all the breeding lines than those of Georgia-06G. In another set of trials, two of those same breeding lines had final late leaf spot ratings similar to those of Georgia-12Y in 2014, whereas in 2015, six of those breeding lines had final leaf spot ratings that were lower than those of Georgia-12Y. Yields were similar for Georgia-12Y and all the breeding lines in the Gibbs Farm trials. Across years and breeding lines at the Lang Farm, the relationship between visual estimates of defoliation and NDVI was described by a two sector piecewise regression with NDVI decreasing more rapidly with increasing defoliation above approximately 89%. The utility of NDVI for spot comparisons among breeding lines appears to be limited to situations where there are differences in defoliation. Georgia-12Y and multiple breeding lines evaluated show potential for use in situations such as organic production where acceptable fungicides available for seed treatment and leaf spot control are limited.

Applications of Mixtures of Copper Fungicides and Chlorothalonil for Management of Peanut Leaf Spot Diseases

2001 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
A. K. Culbreath ◽  
T. B. Brenneman ◽  
R. C. Kemerait
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Field Experiments ◽  
Cercospora Arachidicola ◽  
Copper Oxychloride ◽  
Copper Hydroxide ◽  
Cercosporidium Personatum ◽  
Late Leaf Spot ◽  
Copper Fungicides

Management of early leaf spot (Cercospora arachidicola) and late leaf spot (Cercosporidium personatum) of peanut (Arachis hypogaea) in the southeastern U.S. is dependent upon multiple applications of foliar fungicides. Field experiments were conducted from 1997 to 2000 to compare the efficacy of mixtures of copper hydroxide or copper oxychloride and reduced rates of chlorothalonil with that of full rates of chlorothalonil alone or chlorothalonil + propiconazole. In all tests, rates per ha of 0.70 kg of chlorothalonil + 0.70 kg of copper oxychloride or higher provided leaf spot control that was similar (P > 0.05) to that achieved with standard rates of chlorothalonil (0.84 kg/ha) + propiconazole (0.063 kg/ha). Application of chlorothalonil at 0.56 kg/ha + copper oxychloride at 0.56 kg/ha controlled leaf spot as well as (P > 0.05) chlorothalonil alone at 1.26 kg/ha in five of six tests in which that treatment was evaluated. In three of four tests in 1998 and 1999, application of chlorothalonil at 0.63 kg/ha + copper hydroxide at 0.63 kg/ha controlled leaf spot as well as chlorothalonil alone at 1.26 kg/ha. In both tests in 2000, application of chlorothalonil at 0.84 kg/ha + copper hydroxide at 0.63 kg/ha controlled leaf spot as well as chlorothalonil alone at 1.26 kg/ha. There were no consistent yield differences among the chlorothalonil, chlorothalonil + propiconazole, or chlorothalonil + copper treatments. Accepted for publication 8 November 2001. Published 16 November 2001.

scholarly journals Screening of different plant extracts against leaf spot (Cercospora arachidicola and Cercosporidium personatum) of groundnut (Arachis hypogaea L.)

2013 ◽  
Vol 38 (3) ◽  
pp. 491-503 ◽  
Author(s):  
MH Hossain ◽  
I Hossain
Keyword(s):  
Plant Extracts ◽  
Leaf Spot ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Plain Water ◽  
Infected Leaf ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum ◽  
Almost All

A study was undertaken to evaluate effectiveness of foliar spray with 33 plant extracts against leaf spot (Tikka) of groundnut caused by Cercospora arachidicola and Cercosporidium personatum. Bavistin and BAU-Biofungicide were included in the experiment as checks and spray of plain water represented control. Almost all treatments gave considerable reduction in disease incidence and increase in growth parameters, pod and haulm yield compared to control. The most effective materials were Bavistin 50 WP, BAU-Biofungicide, leaf extract of neem, tomato, datura black, and datura white. The materials decreased spot number per leaf, defoliation per plant, incidence of leaf spot, and number of infected leaf per plant by 35.45 -60.07, 42.06-72.20, 51.97–63.58, and 38.33 to 46.89 % and increased pod yield and haulm yield by 64.37-111.41 and 32.35- 74.71 %, respectively. The materials may be recommended against the disease after economic analysis. DOI: http://dx.doi.org/10.3329/bjar.v38i3.16976 Bangladesh J. Agril. Res. 38(3): 491-503, September 2013

Efficacy of Organically Acceptable Fungicides for Management of Early and Late Leaf Spot Diseases on Partially Resistant Peanut Cultivars

2008 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
E. G. Cantonwine ◽  
A. K. Culbreath ◽  
B. B. Shew ◽  
M. A. Boudreau
Keyword(s):  
North Carolina ◽  
Copper Sulfate ◽  
Leaf Spot ◽  
Field Experiments ◽  
Disease Suppression ◽  
Yield Response ◽  
Cercospora Arachidicola ◽  
Late Leaf Spot ◽  
Cupric Hydroxide ◽  
Affect Disease Severity

Field experiments were carried out in Georgia and North Carolina to evaluate the efficacy of fungicides approved for the organic management of early leaf spot, caused by Cercospora arachidicola, and late leaf spot, caused by Cercosporidium personatum, in peanut (Arachis hypogaea) fields planted to cultivars with partial resistance to one or both pathogens. Copper treatments alone or in mixtures resulted in less disease than a non-treated control. In Georgia, sulfur provided some disease suppression, but not as much as treatments with copper sulfate. Neem oil did not affect disease severity. Mean pod yields across years were significantly greater than the non-treated control only for copper sulfate in Georgia and cupric hydroxide in North Carolina. The minimal yield response to treatments suggests that under similar situations, the frequency of copper-based fungicide applications may be reduced with little affect on yield. Accepted for publication 16 January 2008. Published 17 March 2008.

scholarly journals Management of Late Leaf Spot of Peanut with Benomyl and Chlorothalonil: A Study in Preserving Fungicide Utility

Plant Disease ◽  
2002 ◽  
Vol 86 (4) ◽  
pp. 349-355 ◽  
Author(s):  
A. K. Culbreath ◽  
K. L. Stevenson ◽  
T. B. Brenneman
Keyword(s):  
Leaf Spot ◽  
Fungicide Resistance ◽  
Field Experiments ◽  
Resistance Management ◽  
Model System ◽  
Systemic Fungicide ◽  
Cercospora Arachidicola ◽  
Pathogen Population ◽  
Late Leaf Spot ◽  
Sterol Biosynthesis Inhibitor

Recent registration of sterol biosynthesis inhibitor and strobilurin fungicides for control of early (Cercospora arachidicola) and late (Cercosporidium personatum) leaf spot diseases of peanut (Arachis hypogaea) has renewed interest in the potential for loss of disease control due to fungicide resistance. The objectives of this study were to use the systemic fungicide benomyl, the protectant fungicide chlorothalonil, and late leaf spot of peanut as a model system to compare fungicide application strategies for fungicide resistance management. Field experiments were conducted at Tifton and Plains, GA, in 1995 and 1996 to determine the effects of alternate applications, mixtures, and alternating block applications of chlorothalonil and benomyl compared with full-season applications of two rates of chlorothalonil and two rates of benomyl alone on late leaf spot of peanut and on the proportion of the pathogen population resistant to benomyl following the various regimes. Tank mix combinations of half rates of the two fungicides and alternations of the full rates of the two fungicides provided better (P ≤ 0.05) control of late leaf spot than full-season applications of either rate of benomyl alone, and were comparable to full rates of chlorothalonil alone. Neither tank mixes nor alternating sprays prevented an increase in the relative frequency of benomyl-resistant isolates compared with other treatments in which benomyl was used. Both mixtures and alternate applications of chlorothalonil and benomyl were effective for management of leaf spot in fields where benomyl alone did not provide season-long leaf spot control.

Screening Groundnut (Arachis hypogeae) Genotypes for Resistance to Early and Late Leaf Spot Diseases

2019 ◽  
pp. 1-9
Author(s):  
M. S. Alidu ◽  
S. Abukari ◽  
M. Abudulai
Keyword(s):  
Leaf Spot ◽  
Agricultural Research ◽  
Block Design ◽  
Northern Region ◽  
Limiting Factors ◽  
Leaf Spot Disease ◽  
Cercospora Arachidicola ◽  
Late Leaf Spot ◽  
Arachis Hypogaea L ◽  
Significant Difference

Background for the Study: Groundnut (Arachis hypogaea L.) is an important crop both in subsistence and commercial agriculture in Ghana. Early leaf spot (Cercospora arachidicola) and late leaf spot (Cercosporidium personata) are major limiting factors to groundnut productivity in Ghana. Aim: The objective of the study was to screen groundnut genotypes for resistance to Early and Late leaf spot diseases. Study Design: The treatments were arranged in a randomized complete block design and replicated three (3) times. Place and Duration of Study: The research was conducted from May to December 2013 at the Savanna Agricultural Research Institute experimental site at Nyankpala in the Northern Region. The site lies between latitude 9°25´141 North and longitude 0°58’142 West and an altitude of 183 m. Methodology: The land was done using a tractor and field divided into plots of 2 m x 5 m with 1 m interval between plots. Sowing was done on 3rd June 2013. One seed was planted per hole at a depth of approximately 4 cm. Early and late leaf spot ratings were recorded at 30, 60 and 90 days after planting, using a ten-point scale. At pod maturity, plants from the middle two rows of each plot were hand-harvested and weights of the above ground foliage and underground pods were oven-dried to obtain dry haulm weight and pod yield respectively. Data collected were subjected to analysis of variance using Genstat statistical package (12th edition). Means were separated using the least significant difference at 5%. Results: The were significant differences (P < .001) among the groundnut genotypes in terms of severity for both early and late leaf spot diseases. F-Mix, NC 7, PC 79-79, F-Mix × SINK 24 and NKATIE-SARI had lowest score for both early and late leaf spot diseases. Among the 21 groundnut genotypes, F-Mix recorded the highest pods yield of 1100kg/ha and haulm weight of 5867 kg/ha followed by NC 7 with total pods yield of 900 kg/ha and haulm weight of 5373 kg/ha. PC 79-79 had a total pods yield of 666.7 kg/ha and haulm weight of 4867kg/ha. The pods yield of F-Mix × SINK 24 was 533.3 kg/ha and haulm weight of 4600 kg/ha. NKATIE-SARI recorded pods yield of 500 kg/ha and haulm weight of 4633 kg/ha. Conclusions: From the study, the genotypes F-Mix, NC 7, PC 79-79, F-Mix × SINK 24 and NKATIE-SARI were found to be resistance to both early and late leaf spot disease whereas Chinese, Doumbala, GM 120, GM 324 and ICGV 86015 were susceptible to both diseases.

scholarly journals An Emerging Strawberry Fungal Disease Associated with Root Rot, Crown Rot and Leaf Spot Caused by Neopestalotiopsis rosae in Mexico

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2054-2059 ◽  
Author(s):  
Angel Rebollar-Alviter ◽  
Hilda Victoria Silva-Rojas ◽  
Dionicio Fuentes-Aragón ◽  
Uriel Acosta-González ◽  
Merari Martínez-Ruiz ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Root Rot ◽  
Phylogenetic Reconstruction ◽  
Elongation Factor ◽  
Fungal Disease ◽  
Crown Rot ◽  
Internal Transcribed Spacer Region ◽  
Pathogenicity Tests ◽  
Vitro Effect

In the 2017 strawberry season, several transplant losses reaching 50% were observed in Zamora, Michoacán Valley, Mexico, due to a new fungal disease associated with root rot, crown rot, and leaf spot. In this year the disease appeared consistently and increased in the following seasons, becoming a concern among strawberry growers. Thus, the aim of this research was to determine the etiology of the disease and to determine the in vitro effect of fungicides on mycelial growth of the pathogen. Fungal isolates were obtained from symptomatic strawberry plants of the cultivars ‘Albion’ and ‘Festival’ and were processed to obtain monoconidial isolates. Detailed morphological analysis was conducted. Concatenated phylogenetic reconstruction was conducted by amplifying and sequencing the translation elongation factor 1 α, β-tubulin partial gene, and the internal transcribed spacer region of rDNA. Pathogenicity tests involving inoculation of leaves and crowns reproduced the same symptoms as those observed in the field, fulfilling Koch’s postulates. Morphology and phylogenetic reconstruction indicated that the causal agent of the described symptoms was Neopestalotiopsis rosae, marking the first report anywhere in the world of this species infecting strawberry. N. rosae was sensitive to cyprodinil + fludioxonil, captan, iprodione, difenoconazole, and prochloraz.

scholarly journals Rational Use of Fungicide Applications to Maximize Peanut Yield Under Foliar Disease Pressure in West Africa

Plant Disease ◽  
2000 ◽  
Vol 84 (11) ◽  
pp. 1203-1211 ◽  
Author(s):  
F. Waliyar ◽  
Moustapha Adamou ◽  
Aoua Traoré
Keyword(s):  
West Africa ◽  
Leaf Spot ◽  
Field Trials ◽  
Cercospora Arachidicola ◽  
Causal Organism ◽  
Late Leaf Spot ◽  
Pod Yield ◽  
Progress Curve ◽  
The Cost ◽  
Disease Pressure

Foliar diseases caused by Cercospora arachidicola, Cercosporium personatum, and Puccinia arachidis are major constraints to peanut production in the world. Fungicides are among the most efficient available control methods. Field trials were conducted in 1991 and 1992 in Benin and Niger, West Africa, to evaluate the cost effectiveness of fungicide application timings and frequencies on four peanut cultivars. A combination of four timings (40, 55, 70, and 85 days after sowing) was scheduled. Early (causal organism, C. arachidicola) and late (caused by C. personatum) leaf spot were prevalent in both years, but late leaf spot was the more economically important disease as shown by high values of area under the disease progress curve. Application of fungicide reduced late leaf spot incidence and increased pod yield. Pod yield responded to an interaction of number and timing of fungicide applications. With appropriate timing two or three fungicide applications were enough to significantly increase pod yield. Properly timed fungicide sprays can result in substantial monetary gains for peanut farmers in West Africa.

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