Evaluation of Groundnut Segregating Population for Resistance to Sclerotium rolfsii. using an Efficient Field Screening Technique

2021 ◽  
Author(s):  
Santoshkumar Pujer ◽  
Babu N. Motagi ◽  
P.V. Kenchanagoudar ◽  
M.V.C. Gowda
Keyword(s):  
Oil Content ◽  
Phenotypic Variability ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Positive Association ◽  
Test Weight ◽  
Stem Rot ◽  
High Frequencies ◽  
Moderate Resistance ◽  
Segregating Population

Background: Stem rot of groundnut caused by Sclerotium rolfsii Sacc. is one of the major constraint to groundnut production in many countries and yield losses upto 10-25% were recorded. Screening of groundnut genotypes for resistance to stem rot under field conditions is complicated by the non-uniform spatial distribution of the pathogen.Methods: A total of 165 segregants derived from TAG 24 and R 9227 were evaluated for resistance to stem and pod rot during rainy and summer seasons by using sick plot technique. The field is artificially inoculated at 30 days interval.Result: Among different parameters, maximum phenotypic variability and heritability were observed for disease at 30, 60, 90 days after sowing. The strong negative associations were observed for disease incidence and plant population and positive association were observed for test weight and pod weight per plant. The higher number of superior segregants was observed for pod weight per plant followed by oil content and test weight as compared to both the parents. Generally, high frequencies of desirable segregants were observed for oil content combined with pod weight per plant followed by test weight and pod weight per plant. Out of 165 lines, only six lines showed moderate resistance to Sclerotium rolfsii with good yield attributing characters, further these lines can be utilized in future breeding programme.

A Comparison of Disease Assessment Methods for Southern Stem Rot of Peanut

2002 ◽  
Vol 29 (1) ◽  
pp. 66-71 ◽  
Author(s):  
S. L. Rideout ◽  
T. B. Brenneman ◽  
K. L. Stevenson
Keyword(s):  
Alternative Assessment ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Correlation Coefficients ◽  
Assessment Method ◽  
Assessment Methods ◽  
Alternative Methods ◽  
Stem Rot ◽  
Disease Assessment ◽  
Time Required

Abstract Southern stem rot (caused by the soilborne fungus Sclerotium rolfsii Sacc.) of peanut (Arachis hypogaea L.) traditionally has been assessed based on the percentage of infected 30.5-cm row segments, commonly referred to as disease incidence. Several alternative disease assessment methods were evaluated in four fungicide trials during the growing season (aboveground ratings) and immediately after peanut inversion (belowground ratings). Pearson's correlation coefficients compared disease assessments and yields for all trials. Across all disease assessment methods, belowground assessments at inversion showed a stronger correlation with yield than in-season aboveground assessments. Several of the alternative assessment methods showed a stronger negative correlation with yield than did the traditional disease incidence rating. However, none of the alternative methods were consistently more precise across all assessment dates and trials. There was a significant positive correlation between many of the alternative methods and the traditional disease incidence method. Furthermore, none of the alternative methods was better than the traditional method for detecting differences among fungicide treatments when subjected to ANOVA and subsequent Waller-Duncan mean separation tests (k-ratio = 100). Based on comparisons of the time required to assess disease intensity, the traditional disease assessment method was found to be the most time efficient method of those tested in this study.

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.

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.

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.

scholarly journals CULTURAL, MORPHOLOGICAL AND PATHOGENICITY CHARACTERS OF SCLEROTIUM ROLFSII CAUSING STEM ROT IN GROUNDNUT

2021 ◽  
Vol 21 (no 1) ◽  
Author(s):  
Sutha Raja Kumar ◽  
R. Arulselvi A ◽  
Rex Immanuel R ◽  
John Chrsitopher D. ◽  
Jaiganesh V. ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Tamil Nadu ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Cent Disease

The present studies were undertaken to investigate the cultural, morphological and pathogenicity characters of Sclerotium rolfsii. Maximum per cent disease incidence was recorded in Nadiyappattu followed by Sivapuri, Kammapuram, Killai, Kurinjipadi, Parangipettai, Chathiram and Puthuchathiram in the decreasing order of merit of Cuddalore district, Tamil Nadu. The native isolates of S. rolfsii were isolated from the respective locations and designated as (SR1 to SR9). All the isolated showed variations with respect to colony character, mycelial growth, no of sclerotia, colour of sclerotia, shape and arrangement of sclerotia. Among the nine isolates of S. rolfsii collected from different groundnut growing areas of Cuddalore district, the isolate (SR5) collected from Nadiyappattu was found to be more virulent and recorded the maximum incidence followed by SR8 collected from Sivapuri. Maximum susceptibility was recorded when the plants are about 45 days showing disease incidence of upto 79.86 per cent.

scholarly journals Effects of Row Pattern, Seeding Rate, and Inoculation Date on Fungicide Efficacy and Development of Peanut Stem Rot

Plant Disease ◽  
2007 ◽  
Vol 91 (3) ◽  
pp. 273-278 ◽  
Author(s):  
L. E. Sconyers ◽  
T. B. Brenneman ◽  
K. L. Stevenson ◽  
B. G. Mullinix
Keyword(s):  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Critical Factor ◽  
Field Studies ◽  
Stem Rot ◽  
Relative Efficacy ◽  
Seeding Rate ◽  
Plant Populations ◽  
Fungicide Efficacy ◽  
Infested Field

Two field studies were conducted in 2000, 2001, and 2002 to determine the effects of row pattern (91.4-cm single or 20.3-cm twin) and seeding rate (single: 12.5, 17.4, or 22.6 seed m-1or twin: 6.2, 8.9, or 11.5 seed m-1) on peanut stem rot (Sclerotium rolfsii) development. The first study was conducted in a naturally infested field and relative efficacy of azoxystrobin (Abound 2.08 F, applied at a rate of 0.3 kg a.i. ha-1 at 60 and 90 days after planting [DAP]) also was evaluated. In this study, stem rot incidence was significantly greater (P < 0.05) in single rows planted at high seeding rates than in twin rows planted at any of the seeding rates. Row pattern did not affect azoxystrobin efficacy, and disease incidence was nearly half as much in twin rows treated with fungicide than incidence in single rows treated with fungicide. In the second field study, individual peanut plants in fumigated plots were inoculated once with S. rolfsii at 50, 70, or 90 DAP. Stem rot incidence at harvest was significantly greater on plants inoculated 50 DAP than plants inoculated 70 or 90 DAP. The incidence of spread to adjacent rows was higher in plots where plants were inoculated at 50 than at 90 DAP. Plants inoculated 90 DAP had less disease at harvest, but often developed more severe symptoms within the first week after inoculation compared with plants inoculated 50 or 70 DAP. Symptoms were more severe in single than in twin rows, and at the higher seeding rates. Data from these studies suggest that the physical spacing between plants is a critical factor in stem rot development both on individual plants and in plant populations.

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.

Occurrence and distribution of cowpea damping-off and stem rot and associated fungi in Benin

2004 ◽  
Vol 142 (5) ◽  
pp. 561-566 ◽  
Author(s):  
A. ADANDONON ◽  
T. A. S. AVELING ◽  
M. TAMO
Keyword(s):  
Cultural Practices ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Pythium Ultimum ◽  
Common Species ◽  
Wide Distribution ◽  
Stem Rot ◽  
Damping Off ◽  
Ecological Zones ◽  
Republic Of Benin

Damping-off and stem rot of cowpea is an important soil-borne disease worldwide. Cowpea fields were randomly chosen in each agro-ecological zone in Benin and surveyed in 2001 and 2002 to determine the occurrence of the diseases throughout the country. Diseased plants, prevailing environmental conditions and cowpea grower cultural practices were recorded and causal agents associated with the disease identified. Results indicated that damping-off and stem rot were distributed throughout Benin. The disease incidence was higher in the South (0·074) and Centre zones (0·063) than in the other zones (<0·02) in the country. Among factors influencing the disease incidence, cultural practices such as sole crop and no-till systems appeared to be most important. Isolated fungi included Sclerotium rolfsii, Fusarium spp., Pythium ultimum, Rhizoctonia solani, Phoma sp., Rhizopus sp. and Trichoderma harzianum. None of the Fusarium, T. harzianum or Rhizopus sp. isolates were pathogenic in the greenhouse. Pythium ultimum, R. solani and Phoma sp. were infrequently isolated and few isolates caused the disease symptoms in the greenhouse. However, this is the first report of Phoma sp. causing damping-off and stem rot of cowpea in Benin. Sclerotium rolfsii was by far the most common species isolated from all the agro-ecological zones and all isolates were pathogenic on cowpea in the greenhouse. Sclerotium rolfsii was considered to be the main causal agent of cowpea damping-off and stem rot in the Republic of Benin due to its wide distribution, high incidence and predominance on plants with damping-off and stem rot symptoms.

scholarly journals Comparison of Soil Insecticides Alone and In Combination With PCNB for Suppression of Southern Stem Rot of Peanut1

1988 ◽  
Vol 15 (1) ◽  
pp. 35-38 ◽  
Author(s):  
A. K. Hagan ◽  
J. R. Weeks ◽  
J. A. McGuire
Keyword(s):  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Field Trials ◽  
Disease Suppression ◽  
Stem Rot ◽  
Yield Response ◽  
Control Disease ◽  
Soil Insecticides

Abstract The soil insecticides, chlorpyrifos 15G (2.2 kg a.i./ha), ethoprop 15G (3.3 kg a.i./ha), and fonofos (2.2 kg a.i./ha) were compared with pentachloronitrobenzene (PCNB) 10G (11.2 kg a.i./ha) and PCNB (11.2 kg a.i./ha) + insecticide combinations for suppression of southern stem rot caused by Sclerotium rolfsii on peanut in a series of field trials in 1985, 1986, and 1987 in southeastern Alabama. Stem rot loci counts were reduced each year by chlorpyrifos and two of three years of ethoprop, and fonofos compared to the non-treated control. Disease suppression with chlorpyrifos and ethoprop was similar all three years and two of three years with fonofos to that with the fungicide PCNB. Significant differences (P = 0.05) in yield were noted only in 1986 between each of the soil insecticides and the non-treated control. PCNB and PCNB + insecticide combinations with the exception of PCNB + ethoprop in 1985 significantly increased yields over the non-treated control each year. PCNB + insecticide combinations generally provided better disease suppression and/or yield response than each insecticide but not PCNB applied alone. When data were pooled for all 3 years, all treatments significantly reduced disease incidence and significantly increased yield except fonofos and ethoprop.

Response of Peanut Cultivars to Full and Reduced Spray Programs of Tebuconazole for Control of Southern Stem Rot1

2001 ◽  
Vol 28 (1) ◽  
pp. 5-8 ◽  
Author(s):  
B. A. Besler ◽  
W. J. Grichar ◽  
O. D. Smith ◽  
A. J. Jaks
Keyword(s):  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Yield Response ◽  
Moderate Disease ◽  
Peanut Cultivars ◽  
Disease Pressure

Abstract Eleven commercially grown peanut cultivars were evaluated for disease and yield response to two and four applications of tebuconazole under moderate disease pressure (&lt; 12 hits/12.2 m) by southern stem rot (Sclerotium rolfsii). The incidence of southern stem rot was reduced in all cultivars when treated with two and four sprays of tebuconazole. Tamrun 96 and Southwest Runner had the lowest disease incidence. Cultivars responded with higher yields when sprayed with two and four applications of tebuconazole compared to the unsprayed plots. Peanut grade (SMK + SS) was not affected by tebuconazole. Georgia Runner and Tamrun 96 produced the highest grade while Southwest Runner was the lowest.

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