MORPHOLOGICAL AND PHYSIOLOGICAL PARAMETERS IN YOUNG PLANTS OF Cordia trichotoma SUBMITTED TO THE APPLICATION OF PHOSPHORUS IN THE SOIL

Abstract

The application of phosphorus (P) doses in the soil can increase the growth of native tree species of economic and environmental interest, such as Cordia trichotoma. Thus, this research aims to evaluate the morphological and the physiological parameters in C. trichotoma seedlings, cultivated in soil with increased P content. The experiment was conducted under greenhouse conditions in pots with 2.5 dm^-3 of soil, four doses of P (0, 150, 300 and 450 mg dm^-3), and six replicates. P content in the soil, P concentrations in the leaves, morphological attributes (height, stem diameter, aerial dry matter, root dry matter, and leaf area) and physiological attributes (photosynthetic pigment content and chlorophyll α fluorescence) were determined 180 days after transplantation. The increase in the available P content in the soil allowed greater absorption of this element by the plant’s roots, increasing the concentration in the leaves, and therefore favoring the energetic metabolism of the plants. In addition, the higher influx and accumulation of P in the plant when 450 mg dm^-3 was used, increased the concentration of the photosynthetic pigments and increased the photosynthetic capacity of the C. trichotoma seedlings. The highest use of the light energy by photosystem II (F_v/F_m = 0.76) was observed in the seedlings cultivated with 450 mg dm^-3 of P, with a 95% increase when compared to seedlings without P. Thus, we observed that this tree species is demanding and responsive to the higher P content available in the soil.

Keywords: Chlorophyll a fluorescence; Louro-pardo; Phosphate fertilizer