Effect of Fosfimax 40-20 in the control of Cylindrocarpon macrodydimum on table grapes cropped in the III Region of Chile

The aim of this study was to determine the effectiveness of Fosfimax 40-20 in the control of Cylindrocarpon macrodydimum and other phytopathogenic fungi that affect the root systems of table grapes, in the IIIrd Region of Chile. In vitro and field tests with Fosfimax 40-20 were conducted in Copiapo, where C. macrodydimum and other phytopathogenic fungi of the grapevine root system were causing poor growth and yield of plants in two vineyards that were selected for this experiment. The three treatments included application of Fosfimax 40-20 to soil and foliage, as well as an untreated control. The experimental design was a complete randomized block with three treatments with four replicates. Incidence of the phytopathogenic fungi before and after treatment applications and percentage of yield increase, compared to the control were evaluated. Data were analyzed by ANOVA and Tukey's test. In vitro experiments showed that EC sub(60) values of Fosfimax 40-20 to control C. macrodydimum strains, varied between 20 and 33 ppm of active ingredient, whereas the field trial results showed that product application caused no statistical differences in the incidences of these fungi. However, Fosfimax 40-20 applied to soil caused statistically significant yield increases compared to the untreated control, in two assays. These results show that Fosfimax 40-20 controlled C. macrodydimum in in vitro experiments and field soil applications of, it caused increased yields in treated plants, possibly through control of the phytopathogenic fungi that affect the root system of table grapes.