Effect of Bactericides on Population Sizes and Spread of Clavibacter michiganensis subsp. michiganensis on Tomatoes in the Greenhouse and on Disease Development and Crop Yield in the Field

Abstract

Chemical applications, with the exception of mancozeb, reduced population sizes and spread of Clavibacter michiganensis subsp. michiganensis among tomato seedlings in the greenhouse and impacted subsequent plant development and yield in the field. While applications of copper hydroxide, copper hydroxide/mancozeb, copper hydroxide/mancozeb (premixed 12 h before spraying), streptomycin, and streptomycin/copper hydroxide to seedlings in the greenhouse did not differ significantly from the inoculated control, the trend was for these treatments to increase the survival of inoculated transplants in the field in comparison to the inoculated control. In the field, inoculated controls produced yields that were 63% (1995) and 51% (1996) of those produced by uninoculated controls. In both years, with the exception of mancozeb in 1995, all treatments resulted in yields similar to those obtained with the uninoculated control. Plant survival and yield in the field were severely affected when transplants had a pathogen population of >/= x 10(8) CFU/g of tissue. All treatments, with the exception of mancozeb, limited C. michiganensis subsp. michiganensis populations to <5.0 x 10(5). None of the treatments significantly reduced the incidence of fruit spotting compared with that of the inoculated control.

In vitro comparative study of six commercial formulates on bacterial black spot of mango in Kolar and Chitradurga district, Karnataka

“…Products containing copper has reported to significantly reduce foliar leaf, fruit spotting produced by this pathogen (Gleason et al, 1993). Copper treatments were more active when mixed with mancozeb, suggesting a synergistic effect because mancozeb alone did not reduce populations or spread (Hausbeck et al, 2000). Such enhanced activity has also been reported on Pseudomonas syringae pv.…”

“…By contrast, streptocycline did reduce leaf symptoms produced by spray inoculation in two independent trials, and the black spots on the leaves and stems in one. Bacillus subtilis were considerably reduced in the field by the application of the antagonist (Okigbo and Osuinde, 2003), differences in disease control according to the inoculation method (Hausbeck et al 2000) reported that streptomycin applied to seedlings inoculated by misting increased their survival after transplant and prevented severe disease symptoms from developing in the field, Streptocycline was best chemical for control (Mishra and Prakash, 1992). In our study, streptomycin was used as a positive control.…”

“…Studies on Xcm chemical control are different variable results. With respect to standard bactericides, secondary infection spread of the pathogen in the field can only be reduced by treating seedlings with streptomycin and copper compounds (Hausbeck et al, 2000). The aim of this study was to (i) screen in vitro a range of antimicrobial agents and their effect against Xcm; in laboratory conditions.…”

Epidemiology and Control of Plant Diseases Caused by Phytopathogenic Bacteria: The Case of Olive Knot Disease Caused by Pseudomonas savastanoi pv. savastanoi

“…An interesting example is the combination of cuprocalcic sulfate plus mancozeb because it has a synergistic effect against several bacterial diseases (Hausbeck et al, 2000;Jones et al, 1991;Marco & Stall, 1983). Currently copper oxychloride is the copper compound most commonly recommended against olive knot disease by the Spanish extension services.…”

Mapping, genetic effects, and epistatic interaction of two bacterial canker resistance QTLs from Lycopersicon hirsutum

“…Both strains had been previously characterized by Rep-PCR and belong to the A and C DNA fingerprint classes, respectively (Francis et al 2001;Louws et al 1998). A loop full of Cmm A226 and C290 cells was transferred to two separate flasks containing 5 ml of nutrient broth yeast extract without glucose (NBY; Hausbeck et al 2000;Schaad 1980) and incubated at 25C, 250 rpm, for 48 h. Each 5-ml culture was then inoculated into 1 l of NBY and incubated at 25C, 250 rpm, for 24 h. The cells were pelleted at 10,000 rpm, 4C, for 10 min, resuspended once in ddH 2 O, centrifuged at 10,000 rpm, 4C, for 10 min, and the remaining pellet resuspended in 25 ml ddH 2 O. The bacterial concentrations were estimated by measuring the transmittance of a 1:4 dilution using a Beckman DU 640 spectrophotometer.…”