Effect of nitrogen fertilization on the action of antifungal compounds.

CICORE P.L.; SUAREZ P.A; KORGAN S.; ANDREU A.B; HUARTE MA

San Miguel de Tucuman

Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular. SAIB.; 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular. SAIB.

<!-- /* Font Definitions */ @font-face {font-family:Calibri; mso-font-alt:Arial; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-520092929 1073786111 9 0 415 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:ES-AR; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Phenols have an important role in several plant-pathogen interactions; the concentration of these varies depending on the cultivar, photoperiod and the availability of Nitrogen (N). Our aim was to define the involvement of phenols in reaction to late blight under field conditions and different levels of N. Experimental design was a sub-split plot where the main plots consisted of two potato cultivars, Pampeana INTA (resistant to late blight) and Frital INTA (susceptible), the sub-plots were two frequencies of application of fungicides and the subsubplots were two levels of N, optimal and excessive. There was effect of cultivar on the concentration of phenols and the severity of disease at 82 days after planting (DAP) and 102 DAP. The phenols presented significant differences between levels of N at 102 DAP and the amount of phenols was higher in plots with optimal N in the first and second sampling. We found no differences in the concentration of phenols because of the application of fungicides but there were increases in severity in the plots without fungicides in the second and third assessment. In conclusion, changes in the concentration of phenols due to the application of N and cultivar but not related to the application of fungicides were observed. Therefore, resistance is the product not only of the level of phenols but also of the combination of several factors.