Mycosphaerella berkeleyi. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Geographical Distribution ◽  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Seed Transmission ◽  
Diurnal Periodicity ◽  
Late Leaf Spot ◽  
Conidial State ◽  
Carry Over

Abstract A description is provided for Mycosphaerella berkeleyi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Arachis hypogaea. DISEASE: Late leaf spot of groundnut; also called tikka with Mycosphaerella arachidis (CMI Descript. 411). The circular lesions, up to c. 8 mm diam., become very dark brown or black with the chlorotic halos on the upper surface being less distinct and developing later than those of M. arachidis. Mycosphaerella herkeleyi symptoms are most clearly identified by the distinct dark stroma of the conidial state which develops on the undersurface of the leaf; M. arachidis forms conidia on both surfaces and has no such stroma. Severe attacks cause defoliation (13, 74; 17, 651; 35, 342). GEOGRAPHICAL DISTRIBUTION: Widespread with host (CMI Map 152, ed. 3, 1967). TRANSMISSION: In India the air dispersed conidia showed a diurnal periodicity with a peak at 1000 h (50, 1524). Carry over occurs in host debris (41, 76) and seed transmission seems unimportant.

Mycosphaerella arachidis. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Geographical Distribution ◽  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Leaf Surface ◽  
Seed Transmission ◽  
Diurnal Periodicity ◽  
Leaf Surfaces ◽  
Carry Over

Abstract A description is provided for Mycosphaerella arachidis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Arachis hypogaea. DISEASE: Early leaf spot of groundnut: also called tikka with Mycosphaerella berkeleyi (CMI Descript. 412). Lesions circular, 1-10 mm diam., reddish-brown to black on the upper leaf surface and lighter shades of brown on the lower. Distinct chlorotic halos develop early on the upper surface. The lesions tend to be larger than those of M. berkeleyi and the dark stroma of the latter is absent. The conidia form on both leaf surfaces, the conidiophores being somewhat diffuse. Severe attacks cause defoliation (13, 74; 17, 651; 35, 342). GEOGRAPHICAL DISTRIBUTION: Widespread with host (CMI Map 166, ed. 3, 1966). TRANSMISSION: In India the air dispersed conidia showed a diurnal periodicity with a peak at 1000 h (50, 1524), and in USA most conidia were trapped at 1100-1500 h; rain increased numbers (Smith & Crosby, Phytopathology 63: 703-707, 1973). Carry-over occurs in host debris and seed transmission seems unimportant.

Septoria helianthi. [Descriptions of Fungi and Bacteria].

1970 ◽  
Author(s):  
P. Holliday
Keyword(s):  
Helianthus Annuus ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Seed Treatment ◽  
Seed Transmission ◽  
Adaxial Surface ◽  
Young Leaves

Abstract A description is provided for Septoria helianthi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Helianthus annuus, Helianthus grosseserratus and Helianthus rigidus. DISEASE: Leaf spot of sunflower. Yellowish spots up to 1.5 cm develop over the whole lamina, gradually turning necrotic and becoming almost black. The numerous pycnidia are mostly on the adaxial surface. The lesions have a polygonal outline, being sharply delimited by the veins. Infection may begin on the cotyledons and young leaves, spreading to later developing leaves. Severe attacks lead to defoliation and loss in yield. GEOGRAPHICAL DISTRIBUTION: Fairly widespread in E. Europe and the U.S.S.R. in Asia, China, Japan, Australia (Qd.); E. and S. Africa, N. America (CMI Map 468, ed. 1, 1970). TRANSMISSION: Overwintering occurs in host debris. Seed treatment is recommended although seed transmission does not appear to have been demonstrated. Introduction of the fungus into Hungary may have been via seed (43, 2013).

Effect of In-Furrow Application of Fluopyram on Leaf Spot Diseases of Peanut

Plant Disease ◽  
2021 ◽  
Author(s):  
Albert Culbreath ◽  
Robert Kemerait ◽  
Timothy Brenneman ◽  
Emily Cantonwine ◽  
Keith Rucker
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Fungal Pathogens ◽  
Field Experiments ◽  
Resistance Management ◽  
Feeding Damage ◽  
Early Season ◽  
Late Leaf Spot ◽  
Frankliniella Fusca ◽  
Tobacco Thrips

In peanut (Arachis hypogaea) production, in-furrow applications of the pre-mix combination of the SDHI fungicide/nematicide, fluopyram, and the insecticide, imidacloprid are used primarily for management of nematode pests and for preventing feeding damage on foliage caused by tobacco thrips (Frankliniella fusca). Fluopyram is also active against many fungal pathogens. However, the effect of in-furrow applications of fluopyram on early leaf spot (Passalora arachidicola) or late leaf spot (Nothopassalora personata) has not been characterized. The purpose of this study was to determine the effects of in-furrow applications of fluopyram + imidacloprid or fluopyram alone on leaf spot epidemics. Field experiments were conducted in Tifton, GA in 2015, 2016, and 2018-2020. In all experiments in-furrow applications of fluopyram + imidacloprid provided extended suppression of early leaf spot and late leaf spot epidemics compared to the nontreated control. In 2020, there was no difference between the effects of fluopyram + imidacloprid and fluopyram alone on leaf spot epidemics. Results indicated that fluopyram could complement early season leaf spot management programs. Use of in-furrow applications of fluopyram should be considered as an SDHI fungicide application for resistance management purposes.

Cylindrosporium concentricum. [Descriptions of Fungi and Bacteria].

1977 ◽  
Author(s):  
B. C. Sutton
Keyword(s):  
New Zealand ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
South Australia ◽  
Seed Transmission ◽  
Oil Seed ◽  
Oil Seed Rape

Abstract A description is provided for Cylindrosporium concentricum[Pyrenopeziza brassicae]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Brassica spp. (cabbage, cauliflower, broccoli, brussel sprouts, oil seed rape, swedes). DISEASE: Light leaf spot of Brassicae. GEOGRAPHICAL DISTRIBUTION: Europe (UK, Ireland, Netherlands, Germany, Denmark, Norway, Portugal, Rumania, Latvia); Asia (Japan, Philippines); Australia (South Australia, Tasmania); New Zealand. (CMI Map 193, ed. 2, 1975). TRANSMISSION: By splash-dispersed air-borne conidia. No seed transmission has been demonstrated.

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.

Influence of Broadleaf Weeds on Chlorothalonil Deposition, Foliar Disease Incidence, and Peanut (Arachis hypogaea) Yield

1997 ◽  
Vol 11 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Stanley S. Royal ◽  
Barry J. Brecke ◽  
Frederick M. Shokes ◽  
Daniel L. Colvin
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Field Experiments ◽  
Yield Loss ◽  
Disease Incidence ◽  
Weed Biomass ◽  
Late Leaf Spot ◽  
Foliar Disease ◽  
Weed Density ◽  
Weed Plants

Field experiments were conducted at Jay and Marianna, FL in 1988 and 1989 to determine the effects of sicklepod, Florida beggarweed, and common cocklebur density on chlorothalonil deposition to peanut foliage, peanut foliar disease incidence, and peanut yield. At a density of four weed plants per 8 m of row, Florida beggarweed and sicklepod reduced chlorothalonil deposition on peanut foliage by 20%, while common cocklebur reduced fungicide deposition by 34%. At the same density, incidence of the foliar diseases early leaf spot and late leaf spot increased 10% with Florida beggarweed, 14% with sicklepod, and 20% with common cocklebur compared with weed-free peanut. The predicted peanut yield loss from a weed density of four plants per 8 m was 16 to 19% for Florida beggarweed, 23 to 25% for sicklepod, and 31 to 39% for common cocklebur. Weed biomass increased with increasing weed density.

scholarly journals SSR analysis of cultivated groundnut (Arachis hypogaea L.) germplasm resistant to rust and late leaf spot diseases

Euphytica ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 317-330 ◽  
Author(s):  
E. S. Mace ◽  
D. T. Phong ◽  
H. D. Upadhyaya ◽  
S. Chandra ◽  
J. H. Crouch
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Late Leaf Spot ◽  
Ssr Analysis ◽  
Arachis Hypogaea L

scholarly journals Resistance to late leaf spot and rust diseases in ICRISAT’s mini core collection of peanut (Arachis hypogaea L.)

2015 ◽  
Vol 44 (5) ◽  
pp. 557-566 ◽  
Author(s):  
H. Sudini ◽  
Hari D. Upadhyaya ◽  
S. V. Reddy ◽  
U. Naga Mangala ◽  
A. Rathore ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Core Collection ◽  
Late Leaf Spot ◽  
Mini Core Collection ◽  
Rust Diseases ◽  
Arachis Hypogaea L

scholarly journals Recovery of Valencia Groundnut (Arachis hypogaea L.) Traits in Early Segregating and Promising Late Leaf Spot Resistant Populations

2018 ◽  
Vol 18 (1) ◽  
pp. 57-66
Author(s):  
Wilder Wambi
Keyword(s):  
Cluster Analysis ◽  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Diverse Population ◽  
Diverse Populations ◽  
Backcross Population ◽  
Late Leaf Spot ◽  
Arachis Hypogaea L ◽  
Improvement Programs ◽  
Opportunity For Selection

In Uganda, there are no Valencia varieties that are resistant to leaf spot diseases. Introgression of resistance genes into elite lines is always associated with the transfer of undesirable traits from the donor parents. Knowledge of the degree of genetic relationship provides breeders with a more efficient way to identify populations of potential relevance for their plant improvement programs. The objective of this study was to determine the recovery of Valencia groundnut traits in the early segregating and promising late leaf spot (LLS) resistant populations. Four crosses between Valencia lines (P1) and donor lines (P2) were made. The populations that included F1, F2, BC1P1 and BC1P2, together with their parents (P1and P2) of each of the four crosses namely, Valencia C (P1) × ICGV-SM 02501 (P2), Valencia C (P1) × SGV-07009 (P2), NuMex-M3 (P1) × ICGV-SM 02501 (P2) and Redbeauty (P1) × ICGV-SM 03590 (P2) were evaluated. Cluster analysis revealed differences among the generations for the traits analysed with major and sub-clusters, implying that the generations of crosses formed a genetically diverse population that offers possible opportunity for selection. In the cross between NuMex-M3 X ICGV-SM 02501, the populations BC1P1 and F2, exhibited higher (80 %) recovery of the recurrent parental (NuMex-M3) traits. Similarly, the backcross population (BC1P1) to the susceptible elite variety of the Valencia C X ICGV-SM 02501 cross recovered approximately 75% of the recurrent parental traits Valencia C with lower LLS disease score. Such populations could result in higher gain in Valencia traits and LLS resistance when utilized the breeding program. For maximum gain in LLS resistance and recovery of Valencia traits, more selfing and backcrossing can be performed to fix the genes for LLS resistance as well those of Valencia characteristics. Keywords: cluster analysis; Arachis hypogaea; diverse populations

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