EFFECT OF THE PRODUCTION SYSTEM OF Pinus greggii Engelm. var. australis IN GREENHOUSES ON MORPHOPHYSIOLOGICAL DEVELOPMENT IN THE FIELD

Abstract

To improve the success of the forest conservation and restoration efforts, the morphological and physiological quality of a plant should be taken into account before taking it to the field. The effects of the production process of plants of Pinus greggii Engelm. var. australis in greenhouses and field development were evaluated. Under a completely random experimental design, with factorial arrangement, the following were evaluated: nutritional, conventional (FC) and exponential (FE) addition rate, type of container: black with drainage on the base (NB), white with drainage on the base (BB), black with drainage on the base and lateral (NL), and white with drainage on the base and lateral (BL), substrate: peat moss (Pm), peat mosspine bark (Pm-Cp) and pine bark (Cp). The variables were height (H), diameter at the neck of the root (D), slenderness index (IE), nutrient concentrations (N, P, K). The variance analyses indicated that the three factors affect significantly the morphological variables evaluated except the dry weight of 100 needles. The nutritional supply, type of container, and mix of substrate had significant effects on the foliar concentration of N, P and K after one year since the establishment of the plant. The highest concentration of N, P, K was obtained with FE (0.180%, 825.480 mg kg^-1 and 1608.174 mg kg^-1) against FC (0.171%,
804.346 mg kg^-1 and 1590.026 mg kg^-1, of N, P and K, respectively). Regarding the type of container, NB and NL achieved equally higher concentrations for N (NB=0.183 %), P (NL=863.260 mg kg^-1) and K (NL=1672.379 mg kg^-1). Likewise, the mixture of Pm-Cp and Pm substrate reached higher concentrations of N (Pm-Cp=0.188%), P (Pm=860.193 mg kg^-1) and K (Pm=1721.741 mg kg^-1). Together, the containers NL and BB, and substrate mixtures of Pm and Pm-Cp had significant effects on foliar concentrations of N, P, K. The survival was higher than 90 % in 50 % of the treatments. FE produces better quality plant and higher nutritional load to reforest degraded sites. The NL or BB container and the mixture of Pm-Cp substrate promoted higher foliar concentrations of N and P resulting from the effect of the concentration.