Aspectos biométricos de frutos e sementes, grau de umidade e superação de dormência de jatobá

Abstract

RESUMO. Este trabalho objetivou caracterizar biometricamente sementes e frutos deHymenaea courbaril L. e determinar o grau de umidade, bem como avaliar diferentes tratamentos de superação de dormência. Foram determinados a biometria, a massa de frutos e sementes e o número de sementes por fruto. As sementes foram submetidas aos seguintes cortes: 1-testemunha, sem escarificação ou corte; 2-escarificação em três faces; 3-corte ao meio e 4-corte em quatro partes. Avaliou-se também o percentual de emergência, o IVE, o comprimento da parte aérea e da raiz de plântulas. Para isso, as sementes foram submetidas à superação de dormência, com e sem embebição em água, pelos seguintes tratamentos: Iescarificação do lado oposto ao hilo; II-escarificação em uma lateral; III-escarificação em duas laterais; IV-escarificação em uma lateral e no lado oposto ao hilo; V-escarificação em duas laterais e no lado oposto ao hilo; VI-Testemunha, sem escarificação. O comprimento, a largura, o diâmetro e a massa média dos frutos foram 115,7 mm; 62,18 mm; 43,8 mm e 183,85 g, respectivamente. Para a determinação da umidade, deve-se cortar as sementes em pelo menos duas partes. A escarificação, independentemente da posição na semente, com ou sem embebição em água, possibilita maior qualidade fisiológica. ABSTRACT. Biometric aspects of fruit and seeds, moisture content and overcoming of the dormancy in jatoba. This study aimed to characterize biometrical seeds and fruits of Hymenaea courbaril L., determine the moisture content and assess different treatments to overcome dormancy. Fruit biometry, mass of fruits and seeds, and the number of seeds per fruit were determined. The seeds were submitted to the following treatments: 1-control, without cutting or scarification, 2-scarification on three sides, 3-cut in half and 4-cut in four parts. The percentage of emergence, emergence speed index, length of the buds and root of seedlings were also evaluated. So, the seeds were submitted to overcome dormancy, with and without soaking in water, represented by the following treatments: I-scarification on the opposite side of the hilum, II-scarification on one lateral side; III-scarification on two lateral sides; IV-scarification on one lateral side and on the opposite side of the hilum, V-scarification on two lateral sides and on the opposite side to hilum; VI-control without scarification. The length, width, diameter and the average mass of fruit were 115.7 mm; 62.18 mm, 43.8 mm and 183.85 g, respectively. For the determination of moisture, the seed should be cut in at least two parts. Scarification, regardless of position in seed, with or without soaking in water, allows greater physiological quality.

Methods for overcoming dormancy and seed storage of <i>Enterolobium contortisiliquum

“…These results show that methods that do not allow for water permeation into the seed are ineffective. Similar results were also observed for the seeds of other species, such as the Jatobá or Brazilian Cherry (Hymenaea courbaril L.); the seeds of this tree present exogenous dormancy and an intact tegument before seeding, and these characteristics lead to a low percentage of germination (Andrade, Bruno, Oliveira, & Silva, 2010).…”

Influence of the functional traits of seeds on germination dynamics and morphofunctional pattern of the seedlings

“…The morphological differences exhibited in the seminal structure are related to ecological functionality adapted to variations in environmental conditions (Andrade et al, 2010). Thus, the morphological suitability of seedlings to environmental conditions may interfere with the reproductive success of the species (Lobo, Santana, Salomão, Rehbein, & Wielewicki, 2014).…”

“…Tropical trees exhibit high variability regarding seed morphofunctional characteristics, since the absence or presence of energy reserves determine cotyledon function, which consequently affect seedling establishment and directly influence the successional dynamics of the species (Andrade, Bruno, Oliveira, & Silva, 2010). In this sense, it is necessary to expand studies including silvicultural information on forest species, because according to Ribeiro et al (2009), rational management based on scientific, social and economic interest depends on the knowledge of the regenerative and productive capacity of forests.…”

Morphological integration between seeds and seedlings ofHymenaea courbaril

“…Silva et al [34] presented a slightly wider range from 2.62 to 4.36 g. But consistent wider ranges could be found in Andrade et al [35], which found seeds from 4.08 to 11.2g. Those last authors also mention that moisture content could also be responsible for the variations between seed mass, which was still indicated in other previous studies [36].…”

“…Tropical arboreous species usually present a high variability in seed mass [4].Other studies mention that seed weight is highly variable due to the water content [35], which also varies according to some environmental conditions during seed development, and features, such as maturation stage [36], [37]. However, this species seed moisture content could vary between 12.46 until 16.05 % of the weight [37], a very strict range in view of the diversity of values found to seed weigh disposable in the literature, or even the present study variation.…”