Storage and methods for overcoming dormancy of the coral tree seeds

Abstract

The coral tree (Erythrina velutina Willd.) is an arboreal species that occurs in northeast Brazil and is used in popular medicine to fight cough, asthma, oral diseases, nervous breakdowns, muscle aches and fevers. The process of formation of seedlings of the species is difficult because of the occurrence of seed dormancy. The aim of this study was to evaluate the effect of different methods for overcoming dormancy in seeds of the coral tree stored in different conditions and periods. The experimental design was completely randomized in factorial scheme 5 x 2 (methods for overcoming dormancy and storage types), in four replicates of 25 seeds. The methods used were (S1) control, (S2) scarification opposite the micropyle; (S3) by the scarification micropyle; (S4) seeds immersed in water at 80 °C for five minutes and (S5) seeds immersed in water at 100 °C for two minutes. The storage types were for 25 months at cold chamber and for a month at the laboratory environment. The characteristics evaluated were emergence percentage (PE), time of emergence (TM), shoot length (CPA) and root (CR), diameter (D), leaf number (NF), dry biomass of roots (MSPA) and of shoots (MSR) of seedlings. The emergence percentage was low in treatments S1, S4 and S5 and the seeds stored for one month were more affected when immersed in hot water. The highest values of CPA, CR, MSPA and NF treatments were observed in S2 and S3, which occurred in the lowest average time of emergence. The tegument dormancy of seeds of Erythrina velutina is overcome by scarification with sandpaper on the end opposite the micropyle or next to it. The seed dormancy is not affected by the types of storage and is not overcome by immersion in hot water.