combined farm gate value of over $583 million ( USDA-NASS, 2011 ). Bacterial wilt of tomato caused by the soilborne bacterium Ralstonia solanacearum race 1 (biovar 1, phylotype II) is widely distributed in the southeastern United States and causes
Theodore McAvoy, Joshua H. Freeman, Steven L. Rideout, Stephen M. Olson and Mathews L. Paret
Adam F. Wimer, Steven L. Rideout and Joshua H. Freeman
About 4500 acres of fresh market tomato are grown annually on the ESV ( U.S. Department of Agriculture, 2009 ). Bacterial wilt, caused by Ralstonia solanacearum , is an economically important disease of tomato grown on the ESV and throughout the
Ahmad Shah Mohammadi, Elizabeth T. Maynard, Ricky E. Foster, Daniel S. Egel and Kevin T. McNamara
that causes bacterial wilt. Bacterial wilt is a major disease of cucurbits in the United States ( Latin, 1993 ; Smith, 1911 ). Bacteria are introduced to plants when cucumber beetles carrying E. tracheiphila in their gut feed on plants and leave
David H Suchoff, Frank J. Louws and Christopher C. Gunter
showing severe bacterial wilt symptoms at the on-farm location in Salisbury, NC in naturally infested soils. Field layout. Soil type at HCRS was an Orangeburg sandy loam with pH 6.2 and cation exchange capacity (CEC) of 4.0 meq/100 cm 3 . Soil type at PRS
Elsa S. Sánchez, Ermita Hernández, Mark L. Gleason, Jean C. Batzer, Mark A. Williams, Timothy Coolong and Ricardo Bessin
, muskmelon growers rank the cucumber beetle/bacterial wilt complex as their most important pest problem ( Bessin et al., 2003 ; Hoffmann, 1999 ). Striped and spotted cucumber beetles can cause direct feeding damage and vector E. tracheiphila , the causal
Carol A. Bobisud, Susan P. Martin and Terry T. Sekioka
`Healani' tomato (Lycopersicon esculentum Mill.) somaclones were tested in a bacterial wilt (Pseudomonas solanacearum E.F. Smith) infected field. Survival percentages of selected somaclonal lines were from 40% to 100%, while the original `Healani' had a survival rate of 0% and resistant `Kewalo' had 30%. Eighteen bacterial wilt resistant somaclonal lines were selected and tested for retention of horticultural characters in a noninfected field. `Healani' significantly outyielded all tested somaclonal lines in total fruit weight and total number of fruit per plant. `Healani' had greater fruit diameter than seven of the lines, greater width of the outer wall of the fruit pericarp than seventeen of the lines, and fewer locules in the fruit than seven of the lines.
Samuel F. Hutton, John W. Scott and Gary E. Vallad
University of Florida, Fla. 8233, Fla. 8517, and Fla. 8326, were each crossed with Fla. 7946, and Fla. 8233 was also crossed with Fla. 8111B. Both Fla. 7946 and Fla. 8111B are highly susceptible to bacterial spot, and Fla. 7946 has resistance to fusarium wilt
D.O. Chellemi, H.A. Dankers, S.M. Olson, N.C. Hodge and J.W. Scott
Several procedures for evaluating the resistance of tomato (Lycopersicon esculentum Mill.) to bacterial wilt were used to account for diversity in strains of Pseudomonas solanacearum Smith and to approximate resistance under field conditions. Five strains of P. solanacearum from Florida and one from North Carolina were inoculated onto 19 tomato genotypes and one tomatillo (Physalis ixocarpa Brot.) genotype using a stem-puncture technique. Genotypes were also transplanted as seedlings into naturally infested soil. Resistance was evaluated by comparing the response of each genotype to the susceptible cultivars Bonny Best and Sunny. With the stem-puncture technique, the mean incidence of disease ranged from 30% with the strain from North Carolina to 94% with a strain from northern Florida. Significant differences in the resistance of genotypes and pathogenicity of strains were observed. However, no interaction between strain and genotype was observed. Using naturally infested soil, the mean incidence of disease was 51% and significant differences in the resistance of genotypes were also observed. Hawaii 7997, Hawaii 7998, and CRA 66 had the lowest incidence of disease, regardless of inoculation method. The results indicate that assessing pathogen diversity and using a combination of resistance screening techniques can facilitate the evaluation of many genotypes, account for potential regional variability in the pathogen, and differentiate levels of field resistance to tomato bacterial wilt.
Hiromichi Yamazaki and Tsuguo Hoshina
The relationship between Ca nutrition and bacterial wilt development was studied on three tomato (Lycopersicon esculentum Mill.) cultivar seedlings with various degrees of resistance to the disease. Seedlings were transplanted into nutrient solutions with Ca at 0.4, 4.4, or 20.4 mm. One week after initiating the Ca treatment, tomato seedlings were inoculated by wounding the stem with scissors dipped in a suspension of the pathogen (Pseudomonas solanacearum E.F. Smith). Disease development was rapid in `Ponderosa' (a susceptible cultivar) at all Ca concentrations. Increased Ca concentration in the nutrient solution reduced disease severity in `Zuiei' (a moderately resistant cultivar). Resistance was negated at the low Ca concentration in `Hawaii 7998' (a highly resistant cultivar). Pathogen populations in stems decreased with increased Ca concentrations and degrees of resistance.
Gerald E. Brust and Karen K. Rane
Ten muskmelon (Cucumis melo L.) cultivars were tested for their susceptibility to bacterial wilt, caused by Erwinia trucheiphila (Smith) Bergey, Harrison, Breed, Hammer and Huntoon and vectored by the striped cucumber beetle Acalymma vittatum (F). `Superstar', `Rising Star', `Pulsar', `Caravelle', `Cordele', `Legend', `Makdimon', `Galia', `Rocky Sweet', and `Passport' were used in field studies to determine the number of striped cucumber beetles, feeding damage, and incidence of bacterial wilt. `Makdimon' and `Rocky Sweet' hosted significantly more beetles than the other cultivars. These two cultivars and `Legend' and `Cordele' had much more feeding damage and a significantly higher incidence of bacterial wilt than the others. A greenhouse experiment was conducted with seven of the cultivars to test their susceptibility to bacterial wilt when directly inoculated with the causal agent. All cultivars were equally susceptible to the disease when it was introduced directly into the plant. Selective feeding by striped cucumber beetles was probably most responsible for `Makdimon', `Rocky Sweet', `Legend', and `Cordele' having greater incidences of bacterial wilt than the other cultivars.