Resumo

GUZMAN-PLAZOLA, Remigio A.; FAJARDO-FRANCO, M. Liza; GARCIA-ESPINOSA, Roberto  e  CADENA-HINOJOSA, M. Armando. Epidemic development of tomato powdery mildew and yield of three tomato cultivars in the comarca lagunera, Coahuila, México. Agrociencia [online]. 2011, vol.45, n.3, pp.363-378. ISSN 2521-9766.

Tomato (Solanum lycopersicum) crop in the Comarca Lagunera, Coahuila, Mexico, is affected by powdery mildew (Leveillula taurica). To control this disease intensive spraying of fungicides is carried out in the region. An alternative control strategy is the use of tolerant genotypes. In the present study, an assessment was made of the epidemic development, total yield and commercial quality of three cultivars of the saladette type tomato of indeterminate growth habit (Sun 7705, Sahel and Romana Elite), grown in intensive farming conditions in the open, without application of fungicides in the Comarca Lagunera. The experiments were established in two planting dates during 2006. The experimental design was randomized block with four replications. The results were evaluated by univariate statistical methods and tests of goodness of fit to analytical models. Sahel was more tolerant to disease, recording a greater total yield and yield qualities of the highest economic importance (XXL and XL) than Sun 7705 and Romana Elite. Total yields obtained in the three cultivars were higher in most cases to national average under irrigation. It was estimated that the yields likely to be obtained in the absence of tomato powdery mildew could vary between 82 and 110 t ha^-1. Disease of individual leaves was located in the middle of the canopy and had a predominantly monomolecular dynamics with intrinsic rates mostly below 0.02 lesions lesion^-1 d^-1. The Sahel cultivar appeared to be a good alternative for intensive production of tomato in the region, with low use of fungicides to control powdery mildew.

Palavras-chave : Leveillula táurica; Solanum lycopersicum; epidemic; analytical models; fruit production.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )