Partial resistance of Southern Runner, Arachis hypogaea, to stem rot caused by Sclerotium rolfsii1

1990 ◽  
Vol 17 (2) ◽  
pp. 65-67 ◽  
Author(s):  
T. B. Brenneman ◽  
W. D. Branch ◽  
A. S. Csinos
Keyword(s):  
Arachis Hypogaea ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Field Tests ◽  
Stem Rot ◽  
Pod Yield ◽  
Industry Standard ◽  
Arachis Hypogaea L ◽  
The Mean ◽  
Disease Loci

Abstract The susceptibility of 16 peanut (Arachis hypogaea L.) genotypes (eight Virginia and eight runner types) to southern stem rot (Sclerotium rolfsii Sacc.) was evaluated in field tests over three years. Mean disease incidence for all cultivars was 10.0, 15.4 and 16.4 disease loci per 12.2 m row and average yields were 3488, 2826 and 3569 kg/ha in 1986, 1987 and 1988, respectively. Disease incidence averaged 14.3 disease loci per 12.2 m of row for both market types. The mean yield for the eight Virginia types was 3287 kg/ha versus 3214 for the eight runner types. Culitvars within market types varied significantly in disease incidence and pod yield. Of the Virginia types, NC 6 and Florigiant were the most susceptible with NC 9, VA 81B and Early Bunch being the most resistant. Incidence of stem rot in runner cultivars was high except for Southern Runner and Langley which had about 50% less disease than the most susceptible entries. There was a highly significant correlation (P≤0.01) between yields and disease incidence all three years. Overall, Southern Runner had the lowest disease incidence and highest pod yield of any cultivar. Compared to Florunner, the current industry standard for runner types, Southern Runner had about 50% less disease and yields were 1346 kg/ha higher.

Potential for Improved Control of Southern Stem Rot of Peanut with Resistance and Fungicides1

1985 ◽  
Vol 12 (1) ◽  
pp. 4-7 ◽  
Author(s):  
B. B. Shew ◽  
M. K. Beute ◽  
J. E. Bailey
Keyword(s):  
North Carolina ◽  
Disease Resistance ◽  
Arachis Hypogaea ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Arachis Hypogaea L ◽  
Disease Loci ◽  
Moderate Resistance

Abstract Potential for improved control of southern stem rot caused by Sclerotium rolfsii Sacc.on peanut (Arachis hypogaea L.) was evaluated by combining moderate resistance with fungicide use. Various fungicides including carboxin, oxycarboxin, propiconazol, OAC 3890, and PCNB were applied to peanut lines NC 8C, NC Ac 18016, and Florigiant in North Carolina during 1980, 1981, and 1982. Consistently fewer disease loci occurred on NC Ac 18016 than on NC 8C or Florigiant. At least one fungicide reduced stem rot incidence in two of three years tested, but fungicide use did not result in greater yields. Effects of disease resistance and fungicides on suppression of stem rot development were additive.

scholarly journals Reaction of Select Peanut (Arachis hypogaea L.) Lines to Southern Stem Rot and Pythium Pod Rot Under Varied Disease Pressure

1989 ◽  
Vol 16 (1) ◽  
pp. 9-14 ◽  
Author(s):  
O. D. Smith ◽  
T. E. Boswell ◽  
W. J. Grichar ◽  
C. E. Simpson
Keyword(s):  
Arachis Hypogaea ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Resistant Parent ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
Significant Yield ◽  
Considerable Resistance ◽  
Disease Pressure

Abstract Eight breeding lines, three parents, and the cultivar Florunner were compared under two levels of disease pressure induced by Sclerotium rolfsii Sacc., or Pythium myriotylum Drechs. at each of two locations for three years to ascertain the effectiveness of the host plant resistance to each pathogen. Varied disease pressures were created by application of fungicides and supplement of fungal inoculum. Mean Florunner pod yields varied more than 1000 kg/ha as a result of the S. rolfsii treatments but the yields of the resistant TxAG-3 were not affected. Disease incidence, as measured by frequency of S. rolfsii infection sites and diseased pods, was much higher for Florunner than TxAG-3. Breeding lines for which TxAG-3 was a parent sustained significant yield reductions. The disease incidence in these lines was higher than the resistant parent, equal or less than Tamnut 74, their other parent, and less than Florunner. The grades of TxAG-3 and its derivatives were lower than Florunner. Pod rot incidence differed for the P. myriotylum treatments but pod yields were not different. TxAG-3 and Toalson sustained less pod disease than Florunner and Tamnut 74. The percent of diseased pod tissue for one derivative of Toalson was lower than Toalson and TxAG-3, and that of one TxAG-3 derivative was equal to its best parent. The breeding lines varied in reaction to the two diseases and some lines showed considerable resistance to both organisms.

Control of Southern Stem Rot and Rhizoctonia Limb Rot of Peanut with Flutolanil

1987 ◽  
Vol 14 (2) ◽  
pp. 55-58 ◽  
Author(s):  
A. S. Csinos
Keyword(s):  
Rhizoctonia Solani ◽  
Arachis Hypogaea ◽  
Sclerotium Rolfsii ◽  
Foliar Spray ◽  
Stem Rot ◽  
Initial Development ◽  
Arachis Hypogaea L ◽  
Disease Loci

Abstract Flutolanil (SN 84364) was evaluated in vitro against Sclerotium rolfsii and Rhizoctonia solani AG-4. ED50 values were < 0.01 and < 0.1 μg/mL for S. rolfsii and R. solani, respectively, while Pentachloronitrobenzene (PCNB) had ED50 values of < 0.1 and < 1.0 μg/mL, respectively. Concentrations of flutolanil at 0.1 μg/mL greatly reduced sclerotia and sclerotia initial development of S. rolfsii. Field evaluations were conducted near Tifton, GA, during 1983–86 for control of southern stem rot (S. rolfsii) and Rhizoctonia limb rot (R. solani AG 4) on peanut (Arachis hypogaea L.). Flutolanil 50 WP applied as a banded (40 cm) foliar spray at rates of 1.12 – 5.6 kg ai/ha at pegging (about 60 days post seeding) significantly (P = 0.05) decreased both disease loci numbers caused by S. rolfsii and percentage of vines infected with R. solani. Yields were increased significantly (P = 0.05) in all treatments over the four years of trials. Flutolanil 7 G was significantly (P = 0.05) less effective in controlling southern stem rot and increasing yield than the 50 WP formulation.

scholarly journals Early-Season Fungicide Programs for Peanut Disease Management

2018 ◽  
Vol 19 (1) ◽  
pp. 103-106 ◽  
Author(s):  
Y. C. Tsai ◽  
T. B. Brenneman
Keyword(s):  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Planting Dates ◽  
Early Season ◽  
Yield Increase ◽  
Industry Standard ◽  
Spring Temperatures ◽  
The Mean ◽  
Standard Cultivar

The efficacy of early-season prothioconazole applications on stem rot (Sclerotium rolfsii) epidemics of peanut (Arachis hypogaea) planted on different dates was evaluated to better understand stem rot development and obtain more consistent disease control. The industry standard cultivar (Georgia-06G) was planted on four different dates at about 2-week intervals starting 25 April of both 2012 and 2013. Plots were either not treated or treated with prothioconazole (0.16 kg a.i./ha) at 21 or 35 days after planting (DAP) applied in a 30-cm band. All plots received chlorothalonil (2.09 kg a.i./ha) for leaf spot control. The mean final stem rot incidence in nontreated plots for planting dates 1 to 4 were 32, 15, 13, and 9% in 2012 and 25, 13, 24, and 6% in 2013, respectively. Final incidence of stem rot in plots treated with prothioconazole followed a similar pattern, but disease incidence was reduced by an average of 36 and 46% in 2012 and 4 and 14% in 2013 for the 21 and 35 DAP applications, respectively. Pod yields in nontreated plots for planting dates 1 to 4 (chlorothalonil only) were 6,446, 6,578, 5,479, and 2,613 kg/ha in 2012 and 2,914, 6,456, 5,399, and 3,123 kg/ha in 2013, respectively. Prothioconazole-treated plots (at either 21 or 35 DAP) averaged 475 and 600 kg/ha higher yield than nontreated plots in 2012 and 2013, respectively, but the differences between these two timings were not significant (P > 0.10). Both 2012 and 2013 had relatively cooler spring temperatures and lower risk of early stem rot. The efficacy and yield increase from the early prothioconazole application may have been greater in a warmer spring.

Peanut plants in Queensland infected with tomato spotted wilt virus

1961 ◽  
Vol 12 (2) ◽  
pp. 239 ◽  
Author(s):  
K Helms ◽  
NE Grylls ◽  
GS Purss
Keyword(s):  
Arachis Hypogaea ◽  
Tomato Spotted Wilt Virus ◽  
Disease Incidence ◽  
Infective Virus ◽  
Tomato Spotted Wilt ◽  
Arachis Hypogaea L ◽  
Tagetes Minuta ◽  
New Hosts ◽  
The Mean ◽  
Wilt Virus

A disease of peanut (Arachis hypogaea L.) in Queensland, previously referred to as "chlorosis", was identified as being caused by the tomato spotted wilt virus. Symptoms of the disease on peanut are described. Erigeron bonariensis L., Tagetes minuta L., and Trifolium subterraneurn L. are recorded as new hosts. The disease was not seed-transmitted, although seeds developed lesions and were malformed. Infective virus was found in tissues of the integuments of immature seed. The maximum disease incidence recorded in an individual crop was 5.5%. The mean seed yield of diseased plants was 12.7 g per plant, whereas that of healthy plants was 128.2 g.

Peanut (Arachis hypogaea L.) Response to Bradyrhizobia Inoculant Applied In-furrow with Agrichemicals

2010 ◽  
Vol 37 (1) ◽  
pp. 32-38 ◽  
Author(s):  
David L. Jordan ◽  
P. Dewayne Johnson ◽  
Rick L. Brandenburg ◽  
Joel Faircloth
Keyword(s):  
North Carolina ◽  
Nitrogen Fixation ◽  
Adverse Effects ◽  
Arachis Hypogaea ◽  
Disease Incidence ◽  
Commercial Fertilizer ◽  
Pod Yield ◽  
Arachis Hypogaea L ◽  
Biological Nitrogen ◽  
Fertilizer Solutions

Abstract Bradyrhizobia is often applied in the seed furrow when peanut is planted to ensure nodulation and subsequent biological nitrogen fixation (BNF). Several fungicides, insecticides, and fertilizer solutions are registered for in-furrow application in peanut while others or currently being evaluated for possible use. The effect of these products on efficacy of Bradyrhizobia inoculant has not been thoroughly investigated. Research was conducted in North Carolina and Virginia to determine peanut response to in-furrow application of Bradyrhizobia inoculant alone or with the fungicides azoxystrobin, boscalid, pyraclostrobin, propiconazole plus trifloxystrobin, and tebuconazole; the insecticide imidacloprid; and the commercial fertilizer Asset® RTU. Peanut yield did not differ in three experiments during 2002 when inoculant was applied alone or with the fungicides azoxystrobin, boscalid, pyraclostrobin, propiconazole plus trifloxystrobin, or tebuconazole. In experiments from 2004–2007, pod yield was lower when inoculant was applied with azoxystrobin, pyraclostrobin, tebuconazole, and fertilizer in three of 11, six of 11, three of 8, and three of 11 experiments, respectively, when compared with inoculant alone. Imidacloprid did not affect peanut yield. Pod yield was not improved by any of the fungicide, insecticide, or fertilizer treatments when compared with inoculant alone. These experiments (2004–2007) were conducted in fields without previous peanut plantings or where rotations were long enough to minimize disease incidence. Although benefits of disease control were not defined in these experiments, these data suggest that adverse effects on inoculant can occur when co-applied with azoxystrobin, pyraclostrobin, tebuconazole, and fertilizer.

Effects of Chlorpyrifos on Pod Damage, Disease Incidence, and Yield in Two Peanut Fungicide Programs1

1993 ◽  
Vol 20 (2) ◽  
pp. 102-106 ◽  
Author(s):  
J. W. Chapin ◽  
J. S. Thomas
Keyword(s):  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Field Tests ◽  
Economic Incentive ◽  
Stem Rot ◽  
Ergosterol Biosynthesis ◽  
Insecticide Treatment ◽  
Insect Management ◽  
Net Return ◽  
Production Areas

Abstract The benefits of chlorpyrifos (Lorsban 15G) soil insecticide treatment in standard (chlorothalonil) and developmental (tebuconazole) peanut fungicide programs were compared in five field tests over a 3-yr period. Chlorpyrifos treatment reduced incidence of southern stem rot (Sclerotium rolfsii) and insect pod injury, while increasing yield in the standard fungicide program. In contrast, chlorpyrifos treatment did not measurably affect stem rot incidence or yield in the tebuconazole program, and insect pod injury was reduced in only one of three years. Tebuconazole reduced Rhizoctonia limb rot (R. solani AG-4) and stem rot incidence, and decreased pod injury relative to the standard chlorothalonil program. Tebuconazole increased yield 804 kg/ha (716 lb/ac) over the standard fungicide. Chlorpyrifos increased yield 503 kg/ha (448 lb/ac) for a net return of $315/ha ($128/ac) in the standard fungicide program. However, in the developmental program, chlorpyrifos increased yield only 79 kg/ha (70 lb/ac) for a net return of -$2/ha (-$1/ac). Labeling of ergosterol biosynthesis inhibitor (EBI) fungicides such as tebuconazole would significantly affect peanut insect management in some production areas by reducing the economic incentive for preventative treatments of organophosphate insecticides.

A Comparison of Methods of Evaluating Resistance to Cylindrocladium crotalariae in Peanut Field Tests1

1983 ◽  
Vol 10 (2) ◽  
pp. 66-69 ◽  
Author(s):  
C. C. Green ◽  
M. K. Beute ◽  
J. C. Wynne
Keyword(s):  
Disease Resistance ◽  
Arachis Hypogaea ◽  
Efficient Method ◽  
Root Rot ◽  
Field Tests ◽  
Black Rot ◽  
Mean Square ◽  
Comparison Of Methods ◽  
Arachis Hypogaea L ◽  
The Mean

Abstract Three methods presently used to evaluate disease resistance in peanut (Arachis hypogaea L.) to Cylindrocladium black rot (CBR) were compared to identify the most efficient method to screen peanut lines in field tests. Forty randomly selected F2 families in the F5 generation from a cross of the CBR-resistant source NC 3033 with NC 6 and the two parents were evaluated for percent dead and diseased plants, root rot index and microsclerotia/g of root. Significant differences were detected between the parents (p = 0.05) and among segregates (familes) (p = 0.01) for percent dead and diseased plants only. Error components exceeded the mean square values for differences among segregates for the root rot index and microsclerotia/g of root resulting in no significant differences among entries for these traits and low to no correlations among traits. Percent dead and diseased plants was concluded to be the best of the three methods for screening peanut lines in the field for CBR resistance.

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