Germinação e sobrevivência de Adenium obdesum ( forssk.) (Rosa do Deserto- Apocynaceae) em diferentes substratos.

The extraction of ornamental plants from the forests of Paraná has occurred since the 70's due to the high demand from consumers during the summer season. The reversal of this situation may be associated with the implementation of agronomic crops of species adapted to the region, which would favor the trade of exotic plants, protecting the stocks of native plants. In this context, one species that has been gaining commercial interest is the desert rose, but there are few studies on the cultivation of this species on the coast of Paraná. Thus, a study was carried out to evaluate the germination and survival of Adenium obesum seeds in different substrates. Four alternative substrate types were tested that are easily accessible to the rural producer and low cost: coconut shell fiber, worm humus, humified pine bark, and sieved agricultural soil. The experiment was conducted in an entirely randomized design. The species began germination on the 4th day after sowing and ended at 19.8 days, with the highest germination speeds observed for agricultural soil and worm humus. Among the substrates tested, the highest levels of survival after 60 days of germination were observed for humidified pine bark (n = 88%), followed by worm humus (84%), coconut shell fiber (78%) and agricultural soil (n = 36%). The study concludes that there is the feasibility of reproducing the species for agronomic crops using low-cost and locally abundant substrates based on humidified pine bark, worm humus and coconut shell fiber. [ABSTRACT FROM AUTHOR]