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.

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.

Yield and Market Quality of Seven Peanut Genotypes as Affected By Leafspot Disease and Harvest Date1

1988 ◽  
Vol 15 (1) ◽  
pp. 9-13 ◽  
Author(s):  
D. A. Knauft ◽  
D. W. Gorbet ◽  
A. J. Norden
Keyword(s):  
Disease Incidence ◽  
Major Effect ◽  
Market Quality ◽  
Cercospora Arachidicola ◽  
Breeding Lines ◽  
Genetic Potential ◽  
Arachis Hypogaea L ◽  
Resistant Lines ◽  
Disease Pressure

Abstract The effects of leafspot disease (causal organisms Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton) on the yield and market quality of peanut (Arachis hypogaea L.) must be understood to more accurately assess genetic potential of breeding lines. Seven peanut genotypes were grown without fungicide application at two locations, Gainesville and Marianna FL, for three years and harvested at three biweekly dates. Consistent pod yields near 5000 kg ha-1 were obtained for leafspot resistant breeding line 94 at Marianna when it was harvested later than 142 days after planting (DAP). Other resistant lines also reached maximum production at late harvests, even though disease incidence increased for all resistant lines. Highest yields of susceptible lines occurred ca. 120 DAP, with the susceptible cultivar Florunner producing over 3400 kg ha-1 at Marianna. Although disease pressure on the susceptible lines was heavy at 120 DAP, pod yields did not decline until later harvests, indicating that a major effect of the leafspot disease was the loss of pods already produced. Increased disease pressure was poorly correlation with seed size or total sound mature kernels in either resistant or susceptible lines.

Etiology of Peanut Pod Rot in Nicaragua: II. The Role of Pythium myriotylum as Defined by Applications of Gypsum and Fungicides

2010 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
Joao Augusto ◽  
Timothy B. Brenneman ◽  
Alexander S. Csinos
Keyword(s):  
Arachis Hypogaea ◽  
Crop Yield ◽  
Sclerotium Rolfsii ◽  
Field Trials ◽  
Stem Rot ◽  
Unknown Etiology ◽  
Pythium Myriotylum ◽  
Arachis Hypogaea L

Peanut (Arachis hypogaea L.) is monocultured in western Nicaragua on loamysand soils, and a pod rot of unknown etiology can greatly reduce crop yield. Pythium myriotylum was frequently isolated from symptomatic pods in fields surveyed at Cosiguina, Leon, and Chinandega regions, although Rhizoctonia and Fusarium were also common. Applications of mefenoxam (0.57 kg a.i./ha), azoxystrobin (0.34 kg a.i./ha), and gypsum (670 kg/ha) at beginning pod and 28 to 35 days later were evaluated in field trials to determine their effects on pod rot and yield. Mefenoxam consistently decreased pod rot incidence and increased yield when disease was severe at Cosiguina. In Leon and Chinandega, azoxystrobin increased yield in fields with little pod rot, apparently by controlling stem rot (Sclerotium rolfsii), but did not decrease pod rot incidence. Application of gypsum had no effect on pod rot incidence or yield, but sometimes increased calcium levels in shells. Pod mycoflora isolations and response to mefenoxam suggest P. myriotylum is the primary cause of peanut pod rot in Nicaragua, especially in Cosiguina, where pod rot incidence was high. Accepted for publication 4 November 2009. Published 15 February 2010.

Activity of Fosthiazate against Meloidogyne arenaria, Frankliniella spp., and Sclerotium rolfsii in peanut1

1993 ◽  
Vol 20 (1) ◽  
pp. 66-71 ◽  
Author(s):  
N. A. Minton ◽  
T. B. Brenneman ◽  
K. Bondari ◽  
G. W. Harrison
Keyword(s):  
Arachis Hypogaea ◽  
Organophosphorus Compound ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Emulsifiable Concentrate ◽  
Arachis Hypogaea L

Abstract The efficacy of fosthiazate, a new organophosphorus compound, against the peanut root-knot nematode (Meloidogyne arenaria (Neal) Chitwood), thrips (Frankliniella spp.), and southern stem rot (Sclerotium rolfsii Sacc.) in peanut (Arachis hypogaea L.) was studied for 2 years at Tifton, Georgia. Different rates and methods of applying granular and emulsifiable concentrate formulations of fosthiazate were compared with rates and methods of applying granular fenamiphos and aldicarb which were included as standard treatments. When compared with untreated controls, all treatments of all compounds increased peanut yield and reduced nematode galls on peanut roots, pods, and pegs and thrips damage to foliage significantly in both years. The treatments, however, varied in their effects on southern stem rot. Peanut yields from plots treated with equal rates of the granular and emulsifiable concentrate formulations of fosthiazate were similar. Yields of plots treated with fosthiazate at different rates compared favorably with those treated with comparable rates of fenamiphos and aldicarb. Fosthiazate increased peanut yield as much as 214% in 1990 and 64% in 1991, but yields varied with rates applied.

Maximizing Economic Returns and Minimizing Stem Rot Incidence with Optimum Plant Stands of Peanut in Nicaragua

2010 ◽  
Vol 37 (2) ◽  
pp. 137-143 ◽  
Author(s):  
J. Augusto ◽  
T. B. Brenneman ◽  
J. A. Baldwin ◽  
N. B. Smith
Keyword(s):  
Field Experiments ◽  
Maximum Yield ◽  
Sclerotium Rolfsii ◽  
Disease Spread ◽  
Stem Rot ◽  
Economic Returns ◽  
Plant Populations ◽  
Significant Yield ◽  
Gross Income ◽  
Disease Pressure

Abstract Peanut growers in Nicaragua use high seeding rates, often greatly in excess of the 19.7 seeds/m recommended for growers in Georgia. Significant yield loss to peanut stem rot (caused by Sclerotium rolfsii) often occurs because of rapid disease spread in high density plant stands. It was hypothesized that lower seeding rates would be beneficial, and field experiments were conducted from 2005 to 2006 in Nicaragua to determine the optimum plant stands for stem rot management, peanut yield, and maximum economic returns. The cultivar Georgia Green was planted in twin rows at seven locations with final stands of 4 to 30 plants/m. Paired plots were either treated or not treated with flutolanil to control stem rot. Stem rot incidence consistently increased with higher peanut plant populations in fields with significant levels (>5%) of stem rot. In fields with more than 5% stem rot incidence, peanut yield and gross income adjusted for seed cost were maximized at within row populations of 12 to 13 and 11 plants/m, respectively, when treated with flutolanil to reduce stem rot. When flutolanil was not applied, yield and gross income adjusted for seed cost were maximized at 10 to 11 and 8 to 10 plants/m, respectively. In locations with low stem rot incidence (<5%), maximum yield and gross income adjusted for seed cost were attained at within row populations of 13 and 12 plants/m, respectively. Nicaraguan growers may maximize their economic return by utilizing seeding rates to obtain final stand counts of 8 to 11 plants/m in fields with severe stem rot and 12 plants/m with low disease pressure.

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 (< 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.

Sign in / Sign up

Export Citation Format

Share Document