Abstract

VELAZQUEZ-MENDOZA, Juan; SALGADO-FEREGRINO, Oscar Javier; YANEZ-MORALES, María de Jesús  and  JIMENEZ-CASAS, Marcos. In vitro first report of nutrients and silicon effect over the growth of Phaeocryptopus gaeumannii a pathogen of Pseudotsuga menziesii. Rev. mex. fitopatol [online]. 2017, vol.35, n.1, pp.139-149. ISSN 2007-8080.  https://doi.org/10.18781/r.mex.fit.1609-2.

The development of Phaeocryptopus gaeumannii, Ascomycota, the cause of Swiss needle cast on Douglas-fir foliage (Pseudotsuga menziesii), is influenced by the nutritional composition of the needles. The objective of the study was to examine the effect of different essential elements, macronutrients and micronutrients, for plants and silicon (Si), on the in vitro growth of P. gaeumannii. Two completely random experiments were established with different nutrients. The first was the culture of the fungus in 2 % Malt Extract Agar with 10 treatments, and the relative growth rate was calculated; and the second was in liquid medium of Potato Dextrose with 21 treatments, and the mass of the mycelium was measured. Macronutrients favored the growth of P. gaeumannii. In contrast, Cu, Mn and Zn micronutrients inhibited the development of the fungus in double doses. In general, Si inhibited the growth of the fungus. The complete nutrient solution of macronutrients + micronutrients with 250 and 1000 ppm of Si, indicated that these formulations may contribute to eventual control of P. gaeumannii. This preliminary in vitro trial appears to be the first study.

Keywords : Christmas tree; adjuvant; macronutrients; micronutrients; swiss needle cast; Mexico.

        · abstract in Spanish     · text in English | Spanish     · English ( pdf ) | Spanish ( pdf )