ABSTRACT
The specie Physalis angulata L., who belongs to the Solanaceae family, has stand out as an extremely promising plant in terms of medical use, due to the production of the physalin compound. However, important aspects of its production still remain unknown. Thus the objective of this work was to assess the influence of phosphorus for the growth of these species. The experiment was performed with three doses of P (8, 16 e 64 mg kg-1 de P), in a completely randomized experimental design. Two harvests were performed: at 30 and 42 days after planting. The deficiency of P reduced the number of leaves and leaf area. The total dry matter (DM), as well as a MS from all parts of the plant, was significantly higher for plants grown under the highest levels of phosphorus. Plants grown with 8 mg P kg-1 showed no flowers or fruit; but, for the treatment which used 64 mg of P kg-1 the beginning of flowering happened before than with the plants grown with 16mg. The ratio of the leaf area and the specific leaf area were higher for plants grown under stress, while the values of the relative growth rate and the net assimilatory rate were not statistically influenced. We conclude that the deficiency of P in soil may considerably affect the growth of Physalis plants. Moreover, since the deficiency of P significantly reduced the leaf production, which is responsible for creating the physalin, it is also possible to conclude that P deficiency may, even indirectly, reduce the concentration of this important compound in the plant.
Keywords Physalis angulata; rate growth; dry matter production; phosphorus fertilization