Resumen

MUNOZ FLORES, Hipolito Jesús et al. Plant quality in the La Dieta forest nursery in Zitácuaro municipality, Michoacán state. Rev. mex. de cienc. forestales [online]. 2015, vol.6, n.27, pp.72-89. ISSN 2007-1132.

The low quality of the plants produced in forest nurseries in Mexico is one of the causes of limited success of plantations, causing the national annual rate of survival to be approximately 50 % a year after planting. The aim was to assess, through morphological and physiological indices, the quality of the soilproduced in the forest nursery La Dieta, located in the Zitácuaro municipality, Michoacán state. The plants, grown in black polythene bags, were in a maintenance cycle. A sample of 410 of them was selected at random. The height, root neck diameter and total dry biomass were evaluated; in addition, the Robustness Rate (RR), Lignification Rate (LR) and Dikcson's Quality Index (DQI), as well as the concentration of nutrients (NPK) and the carbon and lignin content were determined. According to the results, the plants surpassed the values required to be rated high quality, with a height of 6.0 cm and a root neck diameter of 5.0 mm for species with a grass-like growth habit, and a height of 15.0 cm and a diameter of 4.0 for species with normal growth. The average DQI values were 2.16 for Pinus michoacana, 1.54 for Pinus ayacahuite and 1.77 for Cupressus lindleyi, all of which are indicative of high quality. The concentrations of nutrients were different in each case, with N and P deficiencies in C. lindleyi and K deficiency in P. michoacana; therefore, these species were rated low quality in regard to this parameter.

Palabras llave : Plant quality; Dickson's quality index; lignification rate; robustness rate; forest plant production; forest nurseries.