Wilt incidence in tomato genotypes (Solanum lycopersicum) in different production systems under shade mesh

Abstract

The objective of this work was to identify the agent associated with wilting disease and evaluate the incidence in nine commercial tomato genotypes: six genotypes with undetermined growth (Cid, Sun 7705, Moctezuma, Cuauhtémoc, Ramses and Aníbal) and three of determined growth (Palomo, Pony express and Toro). The genotypes were evaluated in four shadow mesh production systems: directly on soil, and tezontle substrate in 37x37, 40x40 and 40x45 cm polyethylene plastic bags. The wilt disease incidence was evaluated at 114 days in 3,476 plants. According to morphological characteristics in vitro in PDA medium and humid chamber, only one fungus of the Fusarium genus was isolated from 18/20 plants whereas Fusarium and Rhizoctonia solani were isolated in 2/20. The highest incidence was observed in genotypes Cid (20.1%), Moctezuma (22.4%) and Sun 7705 (29.7%) and the lowest on determined growth genotypes. The 37x37 cm bag production system had the highest wilting disease incidence (25.9%) with 74.3 t ha-1 yield; while in 40x45 cm bags the incidence was lowest (4.7%). In the four production systems, the lowest yield was obtained in Sun 7705 genotype ranging in 59.7 - 70.6 t ha-1.