scholarly journals Precipitação pluvial e épocas de pulverização para controle das manchas foliares (>i/ii/ii/i< L.)

2019 ◽  
Author(s):  
José Ricardo Macedo Pezzopane
Keyword(s):  
Arachis Hypogaea ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum

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.

Control of Early and Late Leafspot on Two Peanut Cultivars1

1983 ◽  
Vol 10 (1) ◽  
pp. 17-21 ◽  
Author(s):  
F. M. Shokes ◽  
D. W. Gorbet ◽  
L. F. Jackson
Keyword(s):  
Disease Control ◽  
Arachis Hypogaea ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum ◽  
Pod Yield ◽  
Arachis Hypogaea L ◽  
T1 And T2 ◽  
Disease Pressure

Abstract The effectiveness of four fungicides for control of Cercospora arachidicola Hori (CA) and Cercosporidium personatum (Berk and Curt.) Deighton (CP) on Arachis hypogaea L. ‘Florunner’ and ‘Early Bunch’ was evaluated in 1978 and 1979. Chlorothalonil (3.5 liters/ha) + flowable sulfur on a 10-day schedule (T1) gave the best control of both leafspots. Chlorothalonil alone (2.3 liters/ha) on a 14-day schedule (T2) provided better disease control and higher pod yields than three other fungicide treatments on both cultivars in 1979. With reduced disease pressure in 1980, triphenytin hydroxide + flowable sulfur and mancozeb + flowable sulfur were almost as effective as T1 and T2 in maintaining high pod yield on Florunner. Yields were significantly less both years on Early Bunch for all treatments other than T1 and T2. The incidence of CA leafspot was low both years and CP was the predominant leafspot pathogen. Significantly higher numbers of CP lesions were observed on Early Bunch than on Florunner at 70 and 90 days after planting (DAP) in 1979 and at 110 DAP in 1980. Numbers of CA lesions on the two cultivars were not significantly different. Average pod yields across fungicide treatments of the two cultivars were not significantly different in 1979 or 1980. Differences in disease levels and pod yields were greater among fungicide treatments than between cultivars.

Management of Leaf Spot Diseases of Peanut With Prothioconazole Applied Alone or in Combination With Tebuconazole or Trifloxystrobin

2008 ◽  
Vol 35 (2) ◽  
pp. 149-158 ◽  
Author(s):  
A. K. Culbreath ◽  
R. C. Kemerait ◽  
T. B. Brenneman
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Field Experiments ◽  
Yield Response ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum ◽  
Late Leaf Spot ◽  
Similar Series

Abstract Field experiments were conducted in Tifton and Plains, GA in 2001–2007 to determine the efficacy of prothioconazole on early leaf spot (Cercospora arachidicola) and late leaf spot (Cercosporidium personatum) of peanut (Arachis hypogaea). In five of six experiments, application of one or both rates (0.18 and 0.20 kg ai/ha) of prothioconazole in sprays 3–6 (chlorothalonil at 1.26 kg ai/ha in sprays 1, 2, and 7) provided leaf spot control superior to tebuconazole (0.23 kg ai/ha) in a similar regime, and superior to chlorothalonil at 1.26 kg ai/ha applied full season (seven times) in four of six experiments. In a similar series of six experiments, application of 0.085 kg ai/ha of prothioconazole + 0.17 kg ai/ha of tebuconazole provided better leaf spot control than tebuconazole (0.23 kg ai/ha) applied in regimes similar to those described above. Leaf spot control with prothioconazole + tebuconazole was similar to chlorothalonil applied at 1.26 kg ai/ha full season in five of eight experiments, but was less effective in the remaining three experiments. Fungicide effects on yield were inconsistent, but in all experiments, yield response with either rate of prothioconazole was similar to or greater than that obtained with 0.23 kg ai/ha tebuconazole on the same schedule. In a third series of four experiments, full-season (seven sprays) application of mixtures of prothioconazole at 0.063 kg ai/ha with trifloxystrobin at 0.063 kg ai/ha gave similar or better leaf spot control than chlorothalonil full season.

scholarly journals Potencial produtivo de linhagens de amendoim do grupo ereto precoce com e sem controle de doenças foliares

Bragantia ◽  
2001 ◽  
Vol 60 (2) ◽  
pp. 101-110 ◽  
Author(s):  
IGNÁCIO JOSÉ DE GODOY ◽  
SÉRGIO ALMEIDA DE MORAES ◽  
ANDREA ROCHA ALMEIDA DE MORAES ◽  
FRANCISCO SEIITI KASAI ◽  
ANTONIO LÚCIO MELLO MARTINS ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum ◽  
Arachis Hypogaea L

Avaliaram-se o potencial produtivo, o rendimento de grãos após descascamento e a massa de grãos de onze linhagens de amendoim (Arachis hypogaea L.) do programa de melhoramento do Instituto Agronômico e da cultivar IAC-Tatu-ST, com e sem controle de doenças foliares. O material genético classifica-se no grupo ereto precoce (A. hypogaea subsp. fastigiata, Waldron). Seis experimentos foram desenvolvidos na época das águas, no Núcleo de Agronomia da Alta Mogiana e na Estação Experimental de Agronomia de Pindorama, em 1994/95, 1995/96 e 1996/97, em esquema com duas parcelas subdivididas, em blocos ao acaso com quatro repetições, em que as parcelas principais consistiram em tratamentos com e sem o controle químico das doenças. As parcelas tratadas foram pulverizadas periodicamente com 3,0 L.ha-1 do fungicida chlorothalonil para controle da mancha-castanha e da mancha-preta (Cercospora arachidicola e Cercosporidium personatum) e da verrugose (Sphaceloma arachidis). A ausência de controle químico resultou em significativas reduções, até de 60%, na produção de todos os genótipos. Com as doenças controladas, as linhagens IAC 5, IAC 21, IAC 22 e IAC 81-12 apresentaram maior potencial produtivo, atingindo 5.000 kg.ha-1 em dois dos experimentos. As linhagens IAC 81-7 e IAC 88-1 apresentaram os melhores desempenhos relativos entre as médias de ambientes com e sem controle químico. As doenças causaram reduções até de 14% no peso médio dos grãos, sobretudo nas linhagens IAC 5, IAC 21 e IAC 22, cujos grãos são de maior tamanho médio. Não foram observadas diferenças significativas em rendimento de grãos entre os tratamentos, na maioria dos ambientes; essa característica mostrou, também, ser pouco influenciada pela presença das doenças.

Tank Mix Combinations of Propiconazole and Chlorothalonil for Control of Leaf Spot Diseases of Peanut

1995 ◽  
Vol 22 (2) ◽  
pp. 101-105 ◽  
Author(s):  
A. K. Culbreath ◽  
T. B. Brenneman ◽  
K. L. Reynolds ◽  
J. M. Hammond ◽  
G. B. Padgett
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Field Experiments ◽  
Quadratic Functions ◽  
Cercospora Arachidicola ◽  
Spot Intensity ◽  
Linear Quadratic ◽  
Cercosporidium Personatum ◽  
Arachis Hypogaea L ◽  
Non Linear

Abstract Field experiments were conducted in one location in 1993 and two locations in 1994 to determine the effects of propiconazole and chlorothalonil tank mix combinations on severity of early (Cercospora arachidicola) and late (Cercosporidium personatum) leaf spot diseases of peanut (Arachis hypogaea L.). In all tests, 10 treatments consisted of 0 and 63 g a.i./ha of propiconazole and 0, 0.315, 0.63, 0.945, and 1.26 kg a.i./ha of chlorothalonil arranged factorially. In 1993, final leaf spot intensity ratings decreased according to nonlinear quadratic functions of chlorothalonil concentrations applied with and without propiconazole. No improvement in leaf spot control was evident with the addition of more than 0.945 kg a.i./ha of chlorothalonil with 63 g a.i./ha of propiconazole. In 1994, conditions were more conducive for leaf spot development. At the Plains location, final leaf spot intensity ratings decreased according to non-linear quadratic functions of chlorothalonil concentrations alone. Leaf spot intensity ratings decreased linearly with increasing rates of chlorothalonil when applied with 63 g a.i./ha of propiconazole. At Tifton, final leaf spot intensity ratings decreased linearly with increasing rates of chlorothalonil with or without propiconazole. Leaf spot intensity ratings were lower on plants treated with tank mixes of chlorothalonil and propiconazole compared to those treated with chlorothalonil alone. Pod yields increased linearly or according to quadratic functions of rates of chlorothalonil with or without propiconazole in both years and all locations. Across all rates of chlorothalonil, yields were higher from plants treated with propiconazole than those treated with the respective rates of chlorothalonil alone.

Isolation of the Phytoalexin Medicarpin from Leaflets of Arachis hypogaea and Related Species of the Tribe Aeschynomeneae

1985 ◽  
Vol 40 (5-6) ◽  
pp. 313-316 ◽  
Author(s):  
R. N. Strange ◽  
J. L. Ingham ◽  
D. L. Cole ◽  
M. E. Cavill ◽  
C. Edwards ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Arachis Hypogaea ◽  
Related Species ◽  
Natural Infection ◽  
Spore Suspension ◽  
Cercospora Arachidicola

Abstract A phytoalexin produced by the leaflets of seven cultivars of Arachis hypogaea (groundnut) after natural infection by Cercospora arachidicola or Phoma arachidicola has been characterised as the isoflavonoid (+)-medicarpin (3-hydroxy-9-methoxypterocarpan). Treatment of excised ground­nut leaflets with an aqueous solution of CuSO4 or with a spore suspension of the fungus Helmin-thosporium carbonum has also been found to stimulate medicarpin biosynthesis.

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

Effect of In-Furrow and Early-Season Banded Applications of Fungicides on Incidence of Early Leaf Spot of Peanut

2015 ◽  
Vol 16 (4) ◽  
pp. 225-229
Author(s):  
Albert K. Culbreath ◽  
Robert C. Kemerait ◽  
Yun-Ching Tsai ◽  
Timothy B. Brenneman ◽  
Katherine L. Stevenson ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Field Experiments ◽  
Disease Incidence ◽  
Cercospora Arachidicola ◽  
Early Season ◽  
Fungicide Application

Field experiments were conducted in Tifton, GA, in 2012-2014 to determine the effect of in-furrow applications of prothioconazole and early-season banded applications of prothioconazole or pyraclostrobin on incidence of early leaf spot (Cercospora arachidicola) of peanut (Arachis hypogaea). In each year, border rows were planted in May as a source of inoculum for plants in the treatment plots. Plots were planted in August or September after epidemics of early leaf spot were severe in the border plots. Fungicide application regimes included two rates (100 and 200 g a.i./ha) of prothioconazole applied in-furrow at planting, and 200 g a.i./ha of prothioconazole or 164 g a.i./ha of pyraclostrobin applied concentrated in a 30-cm band 21 days after planting (DAP). Incidence (percent of leaflets with one or more leaf spot) of early leaf spot was monitored until 54 to 57 days after planting in each year. In all years, disease incidence was below 10% at 28 DAP in plots treated with 200 g a.i./ha of prothioconazole in-furrow compared to over 40% in nontreated plots at the same time. In-furrow applications of 100 g a.i./ha of prothioconazole were less effective, but suppressed leaf spot incidence compared to the control. Banded applications of either fungicide at 21 DAP resulted in a decrease in leaf spot incidence, and prevented increase in leaf spot incidence for 19 days or longer. Accepted for publication 30 November 2015. Published 3 December 2015.

The Choice of Groundnut (Arachis hypogaea) Varieties by Smallholders in South-east Tanzania. I. Observations on Different Varieties

1986 ◽  
Vol 22 (3) ◽  
pp. 269-278 ◽  
Author(s):  
S. R. Preston ◽  
J. H. Simons ◽  
B. R. Taylor
Keyword(s):  
Arachis Hypogaea ◽  
Seed Dormancy ◽  
Moisture Stress ◽  
Yield Losses ◽  
Cercosporidium Personatum ◽  
Varietal Differences ◽  
Puccinia Arachidis ◽  
Short Season

SUMMARYSmallholders in south-east Tanzania grow the groundnut Red Mwitunde (Arachis hypogaea ssp. hypogaea), a long-season variety with seed dormancy, although earlier maturing varieties with no seed dormancy (ssp. hypogaea and fastigiata) usually yielded better in trials, particularly when late sown. Small-seeded, short-season varieties established better in the field than Red Mwitunde and other large-seeded varieties, especially under moisture stress. Trials with selective fungicides to estimate yield losses from leafspots (mainly Cercosporidium personatum) and rust (Puccinia arachidis), jointly and separately, showed no consistent varietal differences.

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