Systemic acquired resistance to manage the Mexican papita viroid in tomato crop (Solanum lycopersicum L.)

Abstract

Objective: To determine the effect of honey, silver nanoparticle, silicon, ethyl extract of bougainvillea (Bougainvillea sp.) and commercial products Actigard^® and Messenger Gold^® in healthy tomato plants and in plants infected with the Mexican papita viroid (MPVd), produced under greenhouse in hydroponic system.

Design/methodology/approach: Healthy and MPVd inoculated Pai-Pai tomato plants were sprayed with different treatments: water, honey, silver nanoparticle, silicon, bugambilia ethyl extract (Bougainvillea spp.), Actigard^® and Messenger Gold^®. The evaluated variables were height, stem diameter and severity per plant, as well as the total harvest per treatment. With severity, the area under the disease progress curve (AUDPC) was determined. The experimental design was completely randomized with 14 treatments and 20 repetitions. The experimental unit was 1 tomato plant. Analysis of variance and multiple comparisons of means were analyzed. Tukey's test with a 5% significance level was analyzed as a posthoc method.

Results: Plants inoculated with Messenger Gold^® and water had the highest AUDPC. Honey and silver had the lowest AUDPC and the lowest final severities. The final severity in inoculated plants was significantly different (p = 0.0050). Regarding stem diameter, treatments had significant differences (p <.0001) but with height, no differences was found between the treatments (p = 0.0681).

Limitations on study/implications: Only one tomato variety was used in the present experiment, so the response with other varieties to the same treatments may be different.

Findings/conclusions: The bee honey proved to be the best inducer of acquired systemic resistance against MPVd. The silver nanoparticle caused the decrease in severity in plants inoculated with MPVd. The bougainvillea extract and the silver nanoparticle favored the performance in non-inoculated plants.

Keywords: Bougainvillea, silver nanoparticle, honney, silicon.