Peanut Genotype and Seeding Rate Effects on Spotted Wilt

2012 ◽  
Vol 13 (1) ◽  
pp. 23 ◽  
Author(s):  
A. K. Culbreath ◽  
W. D. Branch ◽  
J. P. Beasley ◽  
R. S. Tubbs ◽  
C. C. Holbrook

Establishing high plant populations helps suppress epidemics of spotted wilt, caused by Tomato spotted wilt virus (TSWV), in peanut (Arachis hypogaea L.). However, seed costs make it desirable to minimize seeding rates used. To determine whether new resistant genotypes can allow use of reduced seeding rates, field experiments were conducted at Tifton, GA, in 2008-2009 in which seven genotypes were combined factorially with two seeding rates, 9.8 and 19.7 seed/m of row. Genotypes included three cultivars (Georgia Green, Georgia-01R, and Georgia-02C) and four advanced breeding lines (GA 052524, GA 052527, GA 052529, and C724-19-25). Across years and genotypes, final incidences of spotted wilt and standardized areas under the spotted wilt disease progress curves were lower, and yields were higher in all other cultivars and breeding lines than in the moderately TSWV-resistant cultivar Georgia Green. Final incidence of spotted wilt was lower in GA 052527 and GA 052529 than in any of the cultivar standards, and yields of all four breeding lines were higher than for any of the three cultivars. Across genotypes, final incidence of spotted wilt and standardized areas under the spotted wilt disease progress curves were lower and yield was higher for the 19.8 seed/m treatment than the 9.8 seed/m. Accepted for publication 30 November 2011. Published 27 February 2012.

2008 ◽  
Vol 35 (2) ◽  
pp. 92-100 ◽  
Author(s):  
S. D. Riniker ◽  
R. L. Brandenburg ◽  
G. G. Kennedy ◽  
T. G. Isleib ◽  
D. L. Jordan

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.


1995 ◽  
Vol 22 (1) ◽  
pp. 76-80 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Albert K. Culbreath ◽  
Craig K. Kvien

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.


2018 ◽  
Vol 19 (3) ◽  
pp. 201-206 ◽  
Author(s):  
W. D. Branch ◽  
A. K. Culbreath

Tomato spotted wilt disease caused by tomato spotted wilt virus (TSWV) is a major peanut (Arachis hypogaea L.) production problem in the United States. TSWV has become endemic since the mid-1980s in the southeastern U.S. peanut production area. ‘Georgia-06G’ is a large-seeded, TSWV-resistant, runner-type peanut cultivar, whereas ‘Georgia Greener’ is a sister line with a smaller seed size than Georgia-06G. Both Georgia-06G and Georgia Greener have greater TSWV general field resistance with higher yields, total sound mature kernels grade, and dollar values than the parents (‘Georgia Green’ and ‘C-99R’), which shows transgressive segregation for these desirable quantitative traits. Therefore, the objective of this 12-year study was to evaluate the higher TSWV host-plant resistance found in the Georgia-06G over time compared with many other runner- and virginia-type peanut cultivars and advanced breeding lines. Despite yearly variability in TSWV and total disease incidence, the data indicate that Georgia-06G exhibited long-term high TSWV and total disease field resistance at midseason and late season, respectively. Georgia-06G was also found to have among the highest pod yield and dollar value every year. The higher general TSWV field resistance of Georgia-06G appears to be consistent across many years and locations, similar to the moderate TSWV resistance in Georgia Green.


2013 ◽  
Vol 14 (1) ◽  
pp. 15 ◽  
Author(s):  
W. D. Branch ◽  
A. K. Culbreath

The release of high-oleic, United States runner and virginia market type peanut (Arachis hypogaea L.) cultivars has been steadily increasing during the past several years. Two planting dates were utilized for disease evaluation and agronomic performance among these newer high-oleic cultivars. The first planting date test was in mid-April to allow for increased incidence of spotted wilt disease caused by Tomato spotted wilt virus (TSWV). The second planting date test was in mid-May to allow for less TSWV and provide more of an optimum time by comparison. Significant differences (P ≤ 0.05) were found within each of the three (3-year) averages among cultivars for TSWV and total disease (TD) incidence, pod yield, and dollar values. Among the virginia-types, Georgia Hi-O/L, Georgia-05E, and Georgia-08V, and runner-types, Georgia-02C and Georgia-09B, consistently had the lowest TSWV and TD incidence and the highest pod yield and dollar values in both the mid-April and mid-May planting date tests. No significant differences were found between the mid-April and the mid-May planting dates when averaged across this 5-year study for TSWV and TD incidence, pod yield, and dollar values. This suggests that the high-level of TSWV-resistance among these newer high-oleic cultivars should have a greater influence than planting dates on agronomic performance. Accepted for publication 8 June 2013. Published 12 August 2013.


2010 ◽  
Vol 37 (1) ◽  
pp. 83-91 ◽  
Author(s):  
W. D. Branch ◽  
S. M. Fletcher

Abstract Maximum (Max) and minimum (Min) peanut (Arachis hypogaea L.) input production tests were conducted for three consecutive years (2004–06) to evaluate agronomic performance and economic return among several runner and virginia genotypes. Mid-April planting dates were used each year. The Max tests included recommended production practices of seeding rate, fertilization, irrigation, and pesticides; whereas, the Min tests excluded irrigation, insecticides, and included only three fungicide sprays. Results showed variation among years, locations, and genotypes for TSWV and total disease incidence, pod yield, gross dollar value, and dollar value return above variable cost. The performance results also show the benefit to growers from agronomic and economic improvement with many of the newly released peanut cultivars in Georgia. Significant differences (P ≤ 0.05) among the peanut genotypes for tomato spotted wilt disease [caused by Tomato spotted wilt virus (TSWV)] where noted. The lowest TSWV incidence was noted for the cultivars Georgia-06G, Georgia Greener, Georgia-07W, Georgia-08V, Georgia-05E, Georgia-03L, Georgia-02C, Georgia-01R, and AP-3. Highest pod yields were found among Georgia-06G, Georgia Greener, Georgia-07W, Georgia-08V, Georgia-05E, and Georgia-01R. In general, the highest average dollar value return above variable cost was found in the Max test as compared to the Min test, and the highest average dollar value return above variable cost including seed cost was found with the runner-type cultivars Georgia-06G and Georgia Greener.


2003 ◽  
Vol 30 (2) ◽  
pp. 108-111 ◽  
Author(s):  
W. D. Branch ◽  
J. A. Baldwin ◽  
A. K. Culbreath

Abstract Tomato spotted wilt virus (TSWV) resistant, runner-type peanut (Arachis hypogaea L.) cultivars are the most important defense to control spotted wilt disease in southeast U.S. peanut production. The objective of this 3-yr (1999–01) study was to evaluate six TSWV-resistant, runner-type cultivars (Southern Runner, Florida MDR 98, C-99R, ViruGard, Georgia Green, and Georgia-OIR) at three different seeding rates (3, 5, and 7 seed/30.5 cm) in single conventional row patterns for possible genotype (GE) × seeding rate (SR) interaction at the Univ. of Georgia, Coastal Plain Experiment Station. The combined split-plot analyses of variance resulted in highly significant (P ≤ 0.01) GE × SR interaction, which indicates that not all six runner-type cultivars performed the same at each of these three seeding rates. A good example was the TSWV-resistant, runner-type peanut cultivar Georgia Green. It performed subpar at the below normal or lowest seeding rate; whereas at the highest seeding rate, Georgia Green and Georgia-OIR produced the highest pod yields and dollar value returns per hectare among all of these runner-type cultivars. TSWV disease incidence was also significantly lower for the TSWV-resistant Georgia Green cultivar at each of the two higher seeding rates compared to the lowest seeding rate.


1993 ◽  
Vol 20 (2) ◽  
pp. 81-84 ◽  
Author(s):  
A. K. Culbreath ◽  
J. W. Todd ◽  
D. W. Gorbet ◽  
J. W. Demski

Abstract The apparent disease progress of spotted wilt, caused by tomato spotted wilt virus, was monitored in the three component lines of Southern Runner peanut (Arachis hypogaea L.), and in cultivars Southern Runner, Florunner and GK-7 in the field in 1990-1992. In all three years, final incidence and area under the disease progress curves were similar among Southern Runner and all three component lines. Final incidence of spotted wilt in Southern Runner and all component lines was less than for Florunner in all three years. AUDPC values were lower in Southern Runner and two of the three component lines than in Florunner. Incidence and AUDPC of spotted wilt in GK-7 was intermediate between Florunner and Southern Runner and its individual components. Disease increase was linear in all component lines and cultivars. Rate of disease progress was similar among Southern Runner and the three component lines. Disease progressed more slowly in Southern Runner and the component lines than in Florunner.


1999 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
A. K. Culbreath ◽  
J. W. Todd ◽  
D. W. Gorbet ◽  
S. L. Brown ◽  
J. A. Baldwin ◽  
...  

Abstract Epidemics of tomato spotted wilt, caused by tomato spotted wilt Tospovirus (TSWV), were monitored in field plots of runner-type peanut (Arachis hypogaea L.) cultivars Georgia Green and Georgia Runner and numerous breeding lines from four different breeding programs as part of efforts toward characterizing breeding lines with potential for release as cultivars. Breeding lines were divided into early, medium and late maturity groups. The tests were conducted near Attapulgus, GA and Marianna, FL in 1997 and in Tifton, GA and Marianna, FL in 1998. Epidemics in some early and medium maturing breeding lines, including some genotypes with high oleic acid oil chemistry, were comparable to those in Georgia Green, the cultivar most frequently used in the southeastern U.S. for suppression of spotted wilt epidemics. No early maturing breeding lines had lower spotted wilt final intensity ratings or higher yields than Georgia Green. However, spotted wilt intensity ratings in some late maturing lines and a smaller number of medium maturing lines were significantly lower than those of Georgia Green. Several of those lines also produced greater pod yields than Georgia Green. Results from these experiments indicated that there is potential for improving management of spotted wilt though development of cultivars that suppress spotted wilt epidemics more than currently available cultivars. There was no indication that differences in spotted wilt ratings corresponded to differences in numbers of thrips adults or larvae.


2020 ◽  
Vol 110 (6) ◽  
pp. 1199-1207 ◽  
Author(s):  
Thomas M. Chappell ◽  
Clarence B. Codod ◽  
Blake W. Williams ◽  
Robert C. Kemerait ◽  
Albert K. Culbreath ◽  
...  

Management of disease affecting peanut in the southeastern United States has benefited from extensive field research identifying disease-associated risk factors since the 1990s. An assessment of risk factors associated with tomato spotted wilt (TSW), caused by tomato spotted wilt virus and spread exclusively by thrips, is available to growers through Peanut Rx, a tool developed to inform peanut management decisions. Peanut Rx provides an assessment of relative TSW risk as an index. The assessment provides information about the relative degree to which a field characterized by a specified suite of practices is at risk of crop loss caused by TSW. Loss results when infection occurs, and infection rates are determined, in part, by factors outside a grower’s control, primarily the abundance of dispersing, viruliferous thrips. In this study, we incorporated meteorological variables useful for predicting thrips dispersal, increasing the robustness of the Peanut Rx framework in relation to variation in the weather. We used data from field experiments and a large grower survey to estimate the relationships between weather and TSW risk mediated by thrips vectors, and developed an addition to Peanut Rx that proved informative and easy to implement. The expected temporal occurrence of major thrips flights, as a function of heat and precipitation, was translated into the existing risk-point system of Peanut Rx. Results from the grower survey further demonstrated the validity of Peanut Rx for guiding growers’ decisions to minimize risk of TSW.


2005 ◽  
Vol 32 (1) ◽  
pp. 20-24 ◽  
Author(s):  
A. K. Culbreath ◽  
D. W. Gorbet ◽  
N. Martinez-Ochoa ◽  
C. C. Holbrook ◽  
J. W. Todd ◽  
...  

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