Ocorrência e multiplicação de Stylosanthes em Pernambuco

Abstract

The animal production systems in semiarid region are basically extensive and often with animals above the carrying capacity of native pastures resulting in genetic erosion of several species due to overgrazing prevailing in the region. We evaluated the occurrence of Stylosanthes spp in municipalities the semiarid of Pernambuco in 2010-2011 aiming to preserve genetic diversity and multiply the obtained materials. Sampling was performed in 11 representative cities of goat and sheep in the semiarid region of Pernambuco : Serra Talhada, Sertânia, Floresta, Tupanatinga , Bom Jardim , Caetés , Petrolina , Santa Cruz , Santa Cruz Capibaribe , Jataúba and Parnamirim where plants Stylosanthes sp. were collected as well as soil samples for determining the fertility and physical. An experiment of seed germination testing the effect of different heat treatments and light conditions on germination and seedling development of Stylosanthes scabra Vogel was performed. The treatments consist of soaking in water at 100ºC for 0, 20, 40 and 60 seconds and subsequently germinated under light and dark. The experimental design was completely randomized in a 4x2 factorial scheme with four scarification treatments and two light conditions, with 12 replications, each repeat composed of 50 seeds. Another experiment was conducted to evaluate doses indolbutyric acid (IBA ) and thickness of cuttings for vegetative propagation of Stylosanthes scabra Vogel. Cuttin two thicknesses fine ( 2.0 ± 0.5 mm) and coarse (4.0 ± 0.5 mm) and five concentrations of IBA ( 0, 1, 2, 3, and 4g L1 in hydroalcoholic solution). The experimental design was completely randomized with three replications and each plot consisting of 15 cuttings. The factors that determined the occurrence of the genus was the type of soil, and the majority occur in Planossolo and Oxisol with approximately 84.3%. Besides the type of soil characteristics such as average temperature, precipitation, concentration of Ca and Mg and clay percentage were crucial to identify the occurrence of the plant in the municipalities evaluated. In relation to the germination test water in 100º C for 40 s was more efficient in breaking dormancy of Stylosanthes scabra Vogel. favoring greater length and root weight (1.88 and 7.31 g cm) and greater shoot length. Regarding IBA greater length, root weight and mass of shoots with application of 2gL-1 being the best combination for the vegetative propagation of Stylosanthes scabra Vogel was observed 2 g L- 1 IBA in thick piles, because a larger proportion of rooted cuttings.