Abstract

IRIBARREN, María Josefina; GONZALEZ, Beatriz Angela  and  FILIPPINI, Susana. Phytophthora cactorum distribution in a soil profile cultivated with strawberry (Fragaria x ananassa). Summa phytopathol. [online]. 2012, vol.38, n.1, pp. 17-23. ISSN 0100-5405.  http://dx.doi.org/10.1590/S0100-54052012000100003.

Phytophthora cactorum is the causal agent of leather rot, which has led to significant losses in strawberry (Fragaria x ananassa) crops. This pathogen persists as oospores mainly formed in infected fruits, which remain in the soil surface. The study was carried out to investigate, after plantation removal and soil tillage, the spatial distribution of the remaining P. cactorum oospores in a representative lot for strawberry cultivation in the northeast region of the Buenos Aires province, Argentina. Sampling was performed in three blocks located along a transect diagonal to the terrain and at two depth levels in the soil profile. The topography and the soil physical parameters of interest were also evaluated. P. cactorum was detected by using baits. Based on the analysis scale, there were no significant differences regarding pathogen presence at the distinct points set as samples on the soil surface; a slight tendency toward a decrease in the inoculums presence according to depth was observed. The number of positive samples in both depth, A and AB/BA, was 30 and 22 respectably in 72 samples in total. In addition, there were no significant differences in the soil apparent density, equivalent moisture and macroporosity. P. cactorum distribution on the soil surface may have been fundamentally due to natural mechanisms and soil tillage allowed the spread of viable oospores with depth.

Keywords : spatial distribution; leather rot; Fragaria x ananassa.