Seed germination and ideal time for flower buds crop harvesting of "macela" (Egletes viscosa L.) Less.

Abstract

Egletes viscosa (L.) Less., known as “macela", is an annual herb well dispersed throughout the Northeast of Brazil, where it is widely grown. The flower buds, obtained by extractivism, are sold in herbal stores and possess antidispeptic and antidiarrhoeal activity. A literature survey revealed several recent chemical- pharmacological studies, about plant extract or isolated substances from "macela", but the absence of studies of the harvest of flower buds was evident. The aim of this study is the harvest of the buds, as well as the associated chemical aspects. The seedlings were obtained from seeds, soaked in water, planted in isopor trays containing sand as substrata, later transplanted to trays with commercial substrata, and at 2 months, to a 10m², flower bed. The experimental area received organic-mineral fertilizer and supplemental irrigation. Two plants were harvested each 15 days starting on the 50^th day after transplantation (DAT), for eight harvests. The following characteristics were evaluated: quantity of flower buds/plant; flower bud wetght/plant; water content; chloroform extract and essential oil yield for the subsequent inflorescence stages of development: first stage flower bud (FSFB), unripe flower bud (UFB), ripe flower bud (RFB) and dried flower bud (DFB). Germination of newly harvested and dried seeds, previously soaked with an aqueous solution of gibberellic acid (200 ppm) for 24 hours, was also examined. Maturation of the seeds was not uniform; at 110 DAT the maximum productivity of inflorescence (9.8 ton/ha) was observed, allowing an equivalent yield of 36.3, 99.9, 109.7 and 142.8 Kg of chloroform extract/ha, and 1.11, 2.99, 3.32 and 11.16 Kg of essential oil/ha for FSFB. UFB, RFB and DFB, respectively, the low seed germination suggests dormancy for this species.