Intervals and Number of Applications of Acibenzolar-S-Methyl for the Control of Bacterial Spot on Processing Tomato

Abstract

Acibenzolar-S-methyl (ASM) is a plant activator that triggers systemic acquired resistance that is labeled for use in Brazil for managing tomato bacterial spot. The aim of this study was to define the optimum relationship between interval and number of applications of ASM for the most efficacious control of bacterial spot on processing tomato. Four intervals between applications (4, 7, 10, and 14 days) and four application frequencies (4, 6, 8, and 10 applications) were evaluated in five trials performed between 2010 and 2011 in Brasília, Distrito Federal, and in Morrinhos, in the state of Goiás. Copper hydroxide (CH) was applied after ASM applications to complete 13 applications per growing season. Two check treatments were added: standard CH weekly applications and untreated. The following variables were evaluated: severity of bacterial spot, yield, percentage of ripe and rotten fruit, soluble solids content, and the benefit/cost ratio. Disease severity varied between treatments in three trials and yield varied in two trials. A greater number of applications resulted in a reduction of bacterial spot, and the ideal interval between applications was between 8 to 10 days. However, there was a reduction in yield with 10 ASM applications. The temporal effect of ASM applications on bacterial spot severity was evaluated under greenhouse conditions. Reduction in disease severity was observed up to 6 days following ASM application. Additionally, the weekly treatment of seven applications of ASM followed by six applications of CH was compared with a standard program of CH under commercial production conditions in Itaberaí, Goiás, where bacterial spot occurred naturally. The program with ASM and CH resulted in significantly less foliar disease severity than the standard program, which did not result in yield gains. In addition, no differences were detected between the two programs for soluble solids content, industrial yield, plant height, and percentage of ripe and rotten fruit.

A centenary for bacterial spot of tomato and pepper

“…The new compound 3‐indolylacetonitrile significantly reduces bacterial spot on tomato and enhances the efficacy of copper‐based chemicals, for example, Kocide 3000, against the pathogen (Liu et al, 2019 ). Two random peptide mixture compounds (random combination of l ‐phenylalanine and l ‐ or d ‐lysine along the 20‐mer chain length of the peptides) as well as plant activators, for example, ASM, that trigger SAR against the bacterial spot pathogen gave promising results in field conditions (Pontes et al, 2016 ; Topman et al, 2018 ).…”

The Immune Receptor Roq1 Confers Resistance to the Bacterial Pathogens Xanthomonas, Pseudomonas syringae, and Ralstonia in Tomato

“…Copper sulfate and antibiotics such as streptomycin have been used to control Xanthomonas species and P. syringae but have adverse environmental impacts and many strains have evolved tolerance to these chemicals (Kennelly et al, 2007;Griffin et al, 2017). Applying chemicals that induce systemic acquired resistance, such as acibenzolar-S-methyl, can provide partial control but increases production cost and can depress crop yields when used repeatedly (de Pontes et al, 2016).…”

The efficacy of acibenzolar-S-methyl (ASM) in inducing resistance against Fusarium graminearum sensu stricto in wheat (Triticum aestivum L.)

“…The higher ASM concentrations (0.075 g/L and 0.0563 g/L) were more effective when applied at anthesis whereas the lower ASM concentrations (0.0375 g/L and 0.019 g/L) were more effective when applied at the late boot stage. Disease protection usually begins between 4 to 6 days after ASM application on tomatoes (27). Therefore, it was expected that earlier application [at late boot (14 days before anthesis in this study)] would provide more disease reduction.…”