Efeitos da temperatura no processo germinativo de sementes de Acmella Oleracea [(L) R. K. Jansen]

Abstract

The jambu (Acmella oleracea [(L) RK Jansen]) is an herbaceous plant native of the Amazon region that is currently awakening industrial interest due to its economic potential and anesthetic. It is a typical plant of humid tropical climate, well adapted to high temperatures and humidity of the high air. The seeds have well-defined limits of temperature for germination ranging from species to species. The objective was to evaluate the effect of temperature on the germination of seeds jambu. The work was conducted in the entomology laboratory of Embrapa Amazônia Oriental, Belém, PA. The experimental design was completely randomized (DIC), with five treatments and five replications. The treatments were conducted in camera, BOD at temperatures of 23, 26, 29, 32 and 35 C, with relative humidity greater than 90%, and photoperiod of 12 hours. Were evaluated: percentage of the total germination (GERM), germination percentage with 2, 4 and 6 days after the beginning of the experiment, average of germinated seeds per day, germination speed index (GSI), root length (LENGTH) and number of normal seedlings (NPN) and abnormal (NPA). Temperatures of 26 and 29 ° C showed the best germination rate (92 and 88.60%) and GSI (43.72 and 37.88), while the 23 ° C showed the lowest germination (84%) and GSI (21.60). The highest percentage of germinated seeds occurred on the second day, with 23 ° C temperature of the exception that occurred on the fourth day. There was statistical significance for the variables (IVG and CMPR). Temperatures of 29 and 26 ° C showed the longest root. Irrespective of the temperatures measured there was no occurrence of abnormal seedlings. Elevated temperatures such as 35 ° C, eventually contribute significantly to the reduction of the radicle of jambu seedlings.