TEMPERATURA E SUBSTRATO NA GERMINAÇÃO DE SEMENTES DE FLOR-DE-SEDA

Abstract

Silk flower [Calotropis procera (Aiton) R. Br.] is a very common plant in the north-eastern Brazil, used in the animal ration in the period of food scarcity, beyond presenting phytotherapic properties and effect presented against nematoid when incorporated to the ground. The work was considered to evaluate the influence of the substrate and the temperature on the germination of seeds and the development of the seedlings. The knowledge on the germination and the more adjusted substrate can propitiate an increment in the production of seedling of silk flower. The temperature can cause changes in the germination percentage, in the speed and relative frequency of germination. In laboratory experiment using the entirely randomized delineation in array factorial 3 x 3, with 4 repetitions, whose plots had been constituted by 25 seeds. The treatments had been to the combinations of three substrate (paper towel, sand and vermiculite) with three temperatures, 25 ºC (bookshelf coated with plastic canvas), 27 ºC (laboratory environment), 30º C (chamber of controlled temperature). The analyzed variable had been the percentage of germination, VIG, SDM and height dry of the seedlings. Paper towel, under temperatures 27 and 30 °C, showed it more appropriate for the germination five days after the sowing. Sand and vermiculite under temperatures 25 and 27 ºC, showed it more appropriate for the germination and the index of speed of germination twelve days after the sowing. The dry matter of the seedlings, on sand and vermiculite was superior under temperature 30 ºC.