Qualidade de sementes de aroeira do sertão (Myracrodruon urundeuva) submetidas à termoterapia

Abstract

The sanitary quality of the seeds and the irrational exploitation contribute to the extinction of some forest species, such as the Aroeira do Sertão (Myracrodruon Urundeuva Allemão). Currently, there is no chemical recommendation for the treatment of seeds of forest species, a method commonly used for seeds of cultivated plants. Thus, the objective of this research was to determine the efficiency of thermotherapy on the sanitary and physiological quality of seeds of Aroeira do sertão. The experiment was developed at Lafit at the Agrarian Sciences Center, Universidade Federal da Paraíba (CCA/UFPB), in Areia – PB. The seeds of five matrix trees were subjected to thermal treatments, via moist heat, where: T1: control; T2: dicarboximide fungicide (240 g/100 Kg of seeds); T3:40 º C for 5 minutes, T4:40 º C for 10 minutes, T5:40 º C for 15 minutes, T6:40 º C for 20 minutes, T7:50 º C for 5 minutes, T8:50 º C for 10 minutes, T9:50 º C for 15 minutes and T10:50 º C for 20 minutes. The seeds were immersed in the treatments and evaluated the sanitary and physiological qualities. For physiological analysis, the water content was determined, and the germination, the IVG, the percentage of dead seeds, length and dry mass of seedlings were evaluated. The experimental design was completely randomized in the factorial scheme 5x10x4, with 5 matrices, 10 treatments and 4 replicates with 25 seeds each. In the physiological quality, the matrices presented distinct results both in physiological quality, with germination percentage varying from 40 to 70%. In sanity, there were incidences of storage fungi superior to the pathogens. The immersion of seeds at 40 and 50 °c for 5, 10, 15 and 20 minutes were not efficient to control the incidence of Aspergillus Niger, Aspergillus spp., Penicillium spp. and Rhizopus sp. Thermotherapy, in general, compromised the physiological quality of M. Urundeuva matrices. The highest percentages of germination and dry mass were found in Matrix 1.