New Sources of Cylindrocladium Black Rot Resistance among Runner-Type Peanut Cultivars

2012 ◽  
Vol 39 (1) ◽  
pp. 38-42 ◽  
Author(s):  
W. D. Branch ◽  
T. B. Brenneman
Keyword(s):  
Test Site ◽  
Field Trials ◽  
Black Rot ◽  
Breeding Lines ◽  
Cylindrocladium Parasiticum ◽  
Arachis Hypogaea L ◽  
Combined Test ◽  
History Of ◽  
Peanut Cultivars ◽  
Wilt Virus

Abstract Cylindrocladium Black Rot (CBR) caused by Cylindrocladium parasiticum Crous, Wingfield, & Alfenas syn. C. crotalariae (Loos) Bell & Sobers is a major disease problem in southeast U.S. peanut (Arachis hypogaea L.) production. Field trials were conducted for two-years (2008-09) at a test site (Gibbs Farm) that has a long history of continuous peanut production near the Univ. of Georgia, Coastal Plain Expt. Station, Tifton, GA to evaluate for CBR resistance among new runner-type peanut cultivars. All plots were artificially inoculated with microsclerotia of C. parasiticum after planting each year. Significant differences (P≤0.05) were found among the cultivars and advanced breeding lines for both CBR resistance and tomato spotted wilt virus (TSWV) resistance which was also present each year, but the predominant disease was CBR. Georgia Greener, Georgia-06G, Georgia-07W, Georgia-02C, and Carver were consistently found to be the most CBR resistant; whereas, C-99R and Tifguard were the most susceptible each year. In separate CBR tests conducted in 2009 and 2010 at a different location (Blackshank Farm), Georgia Greener also had the least difference, and Tifguard had the greatest difference, between C. parasiticum inoculated versus non-inoculated plots for pod yield. These combined test results demonstrate that useful levels of CBR resistance are currently available in promising new runner-type peanut cultivars.

Variation Among Virginia Market-Type Peanut Genotypes in Susceptibility to Tomato Spotted Wilt Virus Vectored by Thrips (Thysanoptera: Thripidae)

2008 ◽  
Vol 35 (2) ◽  
pp. 92-100 ◽  
Author(s):  
S. D. Riniker ◽  
R. L. Brandenburg ◽  
G. G. Kennedy ◽  
T. G. Isleib ◽  
D. L. Jordan
Keyword(s):  
North Carolina ◽  
Tomato Spotted Wilt Virus ◽  
Field Tests ◽  
Breeding Line ◽  
Breeding Lines ◽  
Tomato Spotted Wilt ◽  
Foliar Symptoms ◽  
Arachis Hypogaea L ◽  
Highly Correlated ◽  
Wilt Virus

Abstract Tomato spotted wilt virus (TSWV), a thrips-vectored tospovirus, is an important pathogen of peanut (Arachis hypogaea L.). Development of tolerant cultivars has proven to be one of the most promising methods to manage the disease. Twenty-four genotypes of virginia market-type peanut were monitored in field tests for thrips damage, and TSWV incidence and severity during 2004 and 2005 in North Carolina. The cultivar Gregory had a higher density of adult thrips in foliage than any other genotype, while breeding lines N01057 and N03054E had the lowest density. No significant correlation was detected between thrips density or injury and TSWV incidence. Line N03036EJ had the greatest TSWV incidence, but did not differ from cultivars Gregory or Perry in incidence. Line N00033 had the least TSWV incidence and differed from the cultivars Gregory and Perry. The occurrence of late-season chlorosis or peanut yellowing death (PYD) was highly correlated with TSWV infection (P < 0.0001). Breeding line N02051ol had the greatest incidence of PYD, but did not differ statistically from Gregory or Perry. Lines N03023EF and N01083 had the least PYD incidence. Plants infected with TSWV not expressing foliar symptoms were found in far greater abundance than plants that were infected and symptomatic. Line N03036EJ had the greatest proportion of infected but asymptomatic plants; line N03054E had the least. Susceptible lines are more likely to become infected, rather than just more likely to show spotted wilt symptoms.

scholarly journals Control of Seed Transmission of Cylindrocladium parasiticum in Peanut with Seed Treatment Fungicides

2003 ◽  
Vol 30 (2) ◽  
pp. 128-133
Author(s):  
D. L. Glenn ◽  
P. M. Phipps ◽  
R. J. Stipes
Keyword(s):  
Seed Treatment ◽  
Standard Treatment ◽  
Seed Transmission ◽  
Field Trials ◽  
Selective Medium ◽  
Significant Suppression ◽  
Greenhouse Trial ◽  
Cylindrocladium Parasiticum ◽  
Untreated Check ◽  
Peanut Cultivars

Abstract Seeds of peanut cultivars VA 98R and NC-V11 with speckled testae were treated with fungicide and assayed on a selective medium to determine the viability of Cylindrocladium parasiticum. The fungus was isolated from 78 and 90% of the untreated speckled seed of the respective cultivars. Seed treatment with captan + pcnb + carboxin, fludioxonil, captan, and thiophanate methyl significantly reduced recovery of the pathogen in both cultivars. Speckled seed of VA 98R and NC-V11 were treated with fungicides and planted in greenhouse and/or field trials in Suffolk, VA. Plants became infected with C. parasiticum after treated and untreated speckled seed were planted in steam-treated soil in the greenhouse. In one trial, seed treatment with fludioxonil, tebuconazole, and LS 176 significantly reduced taproot colonization by C. parasiticum compared to the untreated check. In a second greenhouse trial, only fludioxonil provided significant suppression of disease. In the field, treatment with fludioxonil, thiram, and tebuconazole significantly lowered Cylindrocladium black rot (CBR) incidence compared to the untreated check. Thiram significantly reduced taproot colonization compared to all treatments except fludioxonil. Based on the present study, the addition of thiram and/or fludioxonil to the standard treatment of captan + pcnb + carboxin may offer the best protection against seed transmission of C. parasiticum.

No-Pesticide Preliminary Yield Trials in Peanut1

2001 ◽  
Vol 28 (1) ◽  
pp. 21-24 ◽  
Author(s):  
W. D. Branch ◽  
S. M. Fletcher
Keyword(s):  
Field Tests ◽  
Cercospora Arachidicola ◽  
Breeding Lines ◽  
Net Returns ◽  
Endemic Diseases ◽  
Leaf Spots ◽  
Arachis Hypogaea L ◽  
Alternative Approach ◽  
Wilt Virus ◽  
Yield Trials

Abstract Pest-resistant peanut (Arachis hypogaea L.) cultivars are critically important to reduce the increasing cost of production. Current pesticides used in the U.S. are effective but very expensive. The objective of this study was to evaluate several advanced Georgia breeding lines when grown without nematicides, fungicides, or insecticides. Preliminary yield trials without pesticides were conducted for 3 yr (1996-98) at the Univ. of Georgia, Coastal Plain Exp. Sta. under irrigation. However, preplant and occasionally post-applied herbicides were used for weed control. Thrips damage was noticeably uniform and severe early in the growing season each year, but plants seemingly recovered by midseason. Probably the most endemic diseases in the Southeast are both early and late leaf spots [Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton, respectively] and tomato spotted wilt virus (TSWV). Results from replicated field tests strongly suggest that it would be economically feasible to significantly reduce pesticide cost by growing multiple pest-resistant advanced Georgia breeding lines as compared to the five check cultivars Florunner, GK-7, Southern Runner, Florida MDR 98, and Georgia Browne. However, dollar values were variable and low with no pesticides because of the overall reduction in yield. An alternative approach for greater net returns possibly may be achieved by only reducing currently recommended input costs rather than eliminating pesticides with pest resistant cultivars.

scholarly journals Peanut Peg Strength and Associated Pod Yield and Loss by Cultivar

2017 ◽  
Vol 44 (2) ◽  
pp. 77-82 ◽  
Author(s):  
R. B. Sorensen ◽  
R.C. Nuti ◽  
C.C. Holbrook ◽  
C.Y. Chen
Keyword(s):  
Arachis Hypogaea ◽  
Breeding Lines ◽  
Late Season ◽  
Pod Yield ◽  
Harvest Dates ◽  
Arachis Hypogaea L ◽  
Peanut Cultivars ◽  
Stems And Leaves

ABSTRACT Peanut (Arachis hypogaea L.) peg strength and associated pod yield and digging loss were documented for nine cultivars and two breeding genotypes across three harvest dates (early, mid, and late season) at two Southwest Georgia locations during 2010 and 2011. Cultivars selected were Georgia Green, Georgia Greener, Georgia-02C, Georgia-06G, Georgia-07W, Georgia-09B, Georgia-10T, Florida-07, Tifguard, and advanced breeding lines EXP27-1516 and TifGP-2. Prior to digging, a minimum of three peanut plants from each plot were selected and excess stems and leaves were removed with scissors leaving individual peanut pegs and pods with about 5-cm of stem. Each peanut pod was placed in a “U” shaped metal bracket attached to an electronic force gauge and the stem was pulled manually until the pod detached. After digging and combining, a tractor-mounted scavenger machine was used to collect pods remaining in the soil. Peg strength was greater at Dawson (6.14 N) compared to Tifton (5.28 N) in 2010 but were similar in 2011 (4.51 and 4.39 N, respectively). Dawson had consistently higher yields (5326 kg/ha) and lower pod loss (562 kg/ha) compared with Tifton (3803 kg/ha and 936 kg/ha, respectively). Peanut cultivars with greater peg strength across locations were Georgia-06G, Florida-07, and Georiga-02C. Cultivar Georiga-06G showed the greatest yield across locations and years. Other cultivars may have had stronger peg strength, greater pod yield, or lower pod loss but none were more consistent than these three cultivars across years, locations, and harvest dates.

Inheritance of Dry Matter Deposition and Free Arginine Level in Maturing Peanuts, Arachis hypogaea L

1977 ◽  
Vol 4 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Peter Y. P. Tai ◽  
Clyde T. Young
Keyword(s):  
Dry Matter ◽  
Correlation Coefficients ◽  
Transgressive Segregation ◽  
Quantitative Character ◽  
Partial Dominance ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
Peanut Cultivars ◽  
Broadsense Heritability ◽  
Arginine Level

Abstract Nine F2 families from crosses among six peanut cultivars and breeding lines were used to investigate the inheritance of dry matter deposition and free arginine as a parameter of maturity. Results indicated that dry matter was a quantitative character governed by multiple genes, whereas free arginine level seemed to be controlled by two major genes with partial dominance for the low arginine character. Marked transgressive segregation of F2 families below the lower dry matter parents and above the higher arginine parents was found in most of the nine crosses of various genotypes. Broad sense heritabilities were lower for the dry matter (38 to 78%) than for the level of arginine (60% to 93%). The higher broadsense heritability of the free arginine level in these peanut cultivars examined lends theoretical support to the use of the arginine maturity index (AMI) as a measure of maturation. Correlation coefficients between dry matter and AMI varied from − .198 to − .946.

scholarly journals Seed Transmission of Cylindrocladium parasiticum in Peanut

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 362-370 ◽  
Author(s):  
B. L. Randall-Schadel ◽  
J. E. Bailey ◽  
M. K. Beute
Keyword(s):  
Seed Treatment ◽  
Seed Transmission ◽  
Black Rot ◽  
Seed Industry ◽  
Commercial Seed ◽  
Cylindrocladium Parasiticum ◽  
History Of ◽  
Important Means ◽  
Peanut Production

Seedborne Cylindrocladium parasiticum has been reported in peanuts and the possibility of seed transmission postulated; however, seed transmission has not been documented. Cinnamon brown speckles on peanut testae were correlated with isolation of C. parasiticum. Microscopy indicated that seed were colonized by cinnamon brown colored hyphae and microsclerotia interspersed in and on lightened areas of testa. Speckled seed from commercial seed lots (cultivars NC 7, NC 10C) were planted, with or without a chemical seed treatment (1992, captan + carboxin + dicloran [45:18:15% of product]; 1993 to 1995, captan + PCNB + carboxin [45:15:10% of product]), in fumigated fields with no history of peanut production. Asymptomatic seed from noninfested seed lots (cultivar NC-V 11 or NC 7) were checks for soilborne inoculum. C. parasiticum was isolated from all symptomatic seed lots prior to planting (percentage ranged from 4 to 45%) but was not isolated from asymptomatic seed. Seed transmission occurred from seed both with chemical seed treatment (0.25 to 2.75%) and without seed treatment (0.25 to 6.0%), but not in all years. Asymptomatic seed planted 2.5 cm from speckled seed increased the number of plants with Cylindrocladium black rot from two- to sixfold, illustrating the ability of disease to spread from colonized seed to uninfected plants. It was concluded that seed transmission of C. parasiticum is an important means by which this disease is spread within the seed industry.

scholarly journals Evaluation of Virginia-type Peanut Cultivars for Resistance to Southern Corn Rootworm1

1994 ◽  
Vol 21 (2) ◽  
pp. 88-91
Author(s):  
T. A. Coffelt ◽  
D. A. Herbert
Keyword(s):  
North Carolina ◽  
Soil Types ◽  
Corn Rootworm ◽  
Breeding Lines ◽  
Diabrotica Undecimpunctata Howardi ◽  
Arachis Hypogaea L ◽  
Southern Corn Rootworm ◽  
Production Area ◽  
Peanut Cultivars ◽  
New Cultivars

Abstract Southern corn rootworm (SCRW) (Diabrotica undecimpunctata howardi Barber) is the most damaging soil insect to peanut (Arachis hypogaea L.) in the Virginia-North Carolina production area. New cultivars and advanced breeding lines have not been evaluated for resistance to SCRW. The objective of this 3-yr study was to evaluate three new cultivars (NC-V 11, VA-C 92R, and Agra Tech VC-1) and an advanced breeding line (VA 861101) for resistance to SCRW. NC 6 and NC 9 were used as resistant and susceptible checks, respectively. Pod damage, yield, market grade, and dollar value were obtained for each plot. Agra Tech VC-1, VA-C 92R, and VA 861101 had less total pod damage from SCRW than NC 9. VA 861101 produced significantly higher yields and value per ha than all cultivars on soil types conducive to SCRW damage. Insecticidetreated plots had significantly higher value per ha and lower total pod damage than untreated plots. Results from this study indicate that VA 861101 may be an acceptable replacement for NC 6. Agra Tech VC-1 is the most resistant of the newly released cultivars, but this is not reflected in higher yields.

Response of Eight Peanut (Arachis hypogaea L.) Cultivars to the Herbicide AC 263,222

1995 ◽  
Vol 22 (1) ◽  
pp. 76-80 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Albert K. Culbreath ◽  
Craig K. Kvien
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Field Experiments ◽  
Stem Rot ◽  
Lower Percentage ◽  
Tomato Spotted Wilt ◽  
Arachis Hypogaea L ◽  
Main Effect ◽  
Peanut Cultivars ◽  
Ac 263,222 ◽  
Wilt Virus

Abstract Field experiments conducted in 1992 and 1993 in Georgia evaluated the response of the peanut cultivars Florunner, Georgia Runner, Goldkist GK 7, NC 7, NC-V11, Southern Runner, Sunrunner, and AgraTech VC-1 to AC 263,222 applied early-postemergence (EPOST) at 71 g ha-1. Visual injury, which was less than 13%, was independent of cultivar, and injury was not evident on any cultivar midseason. AC 263,222 slightly reduced canopy width consistently on all cultivars. The only significant effect on percentage fancy pods, medium, No. 1, sound splits, damaged, and other kernels was the main effect of cultivar. There was a significant cultivar, AC 263,222, and cultivar-by-AC 263,222 effect on extra large kernels (ELK) and jumbo kernel percentages. Southern Runner and NC-V11 had significantly lower percentage jumbo and ELK, respectively when treated with AC 263,222. In addition, Florunner and Sunrunner also had numerically less percentage jumbo kernels. Reductions in percentages of ELK and jumbo were probably the result of AC 263,222-induced maturity delays. However, these reductions were not reflected in peanut yields. The occurence of late and early leaf spot, tomato spotted wilt virus (TSWV), and southern stem rot was independent of both cultivar and AC 263,222.

Screening of Virginia-Type Peanut Breeding Lines for Resistance to Cylindrocladium Black Rot and Sclerotinia Blight in the Greenhouse

2008 ◽  
Vol 35 (1) ◽  
pp. 18-24 ◽  
Author(s):  
J. E. Hollowell ◽  
T. G. Isleib ◽  
S. P. Tallury ◽  
S. C. Copeland ◽  
B. B. Shew
Keyword(s):  
Disease Incidence ◽  
Field Performance ◽  
Black Rot ◽  
Block Designs ◽  
Breeding Lines ◽  
Sclerotinia Blight ◽  
Cylindrocladium Parasiticum ◽  
Production Area ◽  
Mist Chamber ◽  
Greenhouse Assay

Abstract Cylindrocladium black rot (CBR) caused by Cylindrocladium parasiticum and Sclerotinia blight caused by Sclerotinia minor are two economically important diseases of peanut (Arachis hypogaea) in the Virginia-Carolina production area. Developing cultivars with resistance to both diseases requires screening of new peanut breeding lines for resistance. Because field evaluations of resistance to these diseases often fail to produce usable results, greenhouse protocols were used to screen breeding lines and cultivars for resistance. For CBR, two seeds of a genotype were planted in a “cone-tainer” filled with a planting medium artificially infested with 25 microsclerotia of C. parasiticum per g of medium. After approximately 8 wk, the roots were washed and rated for degree of decay on a 0–5 proportional scale (0  =  no decay to 5  =  completely decayed). For Sclerotinia blight, plants were inoculated at 6 wk after planting by pushing a plug of potato dextrose agar (PDA) colonized by S. minor and protected from desiccation in a BEEM embedding capsule onto a freshly cut petiole on the main stem of the plant. Inoculated plants were placed in a mist chamber to maintain the high humidity necessary for infection. Lesion lengths were measured 4, 5, 6, and 7 days after inoculation, and areas under the disease progress curves (AUDPC) were calculated. All tests were conducted as incomplete block designs with six replications for CBR tests and four replications for Sclerotinia blight tests. Adjusted entry means were computed from each year's tests and used in summary analyses. Of the 125 breeding lines and checks tested at least once from 2003 through 2006, 51 were tested in at least two years, 34 in at least three years, and 15 lines were tested in all four years. Of the 15 lines tested in all four years, registered germplasm line N96076L had the lowest AUDPC for Sclerotinia blight (58 mm days), but had the greatest CBR root decay score (4.1 decay rating units). Several closely related breeding lines descended from a cross of N96076L and NC 12C were not significantly different from the most resistant line for either disease with scores ranging from 2.2–3.0 decay rating units for CBR and 63–99 mm days for Sclerotinia blight. Correlations of multiple-year greenhouse assay means with field disease incidence means were 0.83 for CBR and 0.35 for Sclerotinia blight. The greenhouse assay for CBR was a reasonably good predictor of field performance, but the assay for Sclerotinia blight was less reliable as a predictor.

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