Journal of Agricultural Science; Vol. 11, No. 16; 2019 ISSN 1916-9752 E-ISSN 1916-9760 Published by Canadian Center of Science and Education 38 Seeds of Carthamus Tinctorius Submitted to Hydration: Morphological Aspects and Emergence Claudia Borgmann 1 , Luciene Kazue Tokura 1 , Bruna de Villa 1 , Deonir Secco 1 , Jair Antonio Cruz Siqueira 1 , Pablo Chang 1 , Alessandra Mayumi Tokura Alovisi 2 , Lucas Iarrocheski Rotta 1 , Vinicius Miola 3 , Leonardo Doreto da Silva 3 , João Vitor Zanella 3 & Milton Felipe Hurban Ramos dos Santos 3 1 Post-graduate Program in Engineering of Energy in Agriculture, State University of West Paraná, Cascavel, Paraná, Brazil 2 Post-graduation Program in Agronomy, Federal University of Grande Dourados, Dourados, Mato Grosso do Sul, Brazil 3 Graduate Program in Agronomy, Assis Gurgacz Foundation University Center, Cascavel, Paraná, Brazil Correspondence: Claudia Borgmann, Post-graduate Program in Engineering of Energy in Agriculture, State University of West Paraná, Rua Universitária, 2069, Jardim Universitário, CEP: 85819-110, Cascavel, Paraná, Brazil. Tel: 55-45-3-220-3151. E-mail: claudia.borg@hotmail.com Received: May 22, 2019 Accepted: July 11, 2019 Online Published: September 30, 2019 doi:10.5539/jas.v11n16p38 URL: https://doi.org/10.5539/jas.v11n16p38 Abstract The present study aimed to evaluate the initial development of safflower genotypes (Carthamus tinctorius) after different periods of seed hydration. For the study two experiments were evaluated. At first, an experiment was performed with 0, 24, 48, 72, 168 and 360 hours of seed hydration, and in the second moment, another with 0, 12, 24, 36, 48 and 60 hours of hydration. The experimental design for the two experiments was completely randomized, with four replicates and six treatments. After 30 days of conduction of the experiments were analyzed the percentage of emergency, index of emergency speed, average time of emergency and average speed of emergency. The evaluated morphological characteristics were plant height, stem diameter, root length, fresh shoot and root mass and dry shoot mass. Hydration of seeds in considerable proportions positively influences the emergence and development of safflower plants. The highest performance in the emergence of plants, size, accumulation of fresh and dry shoot mass and fresh root mass was obtained by the IAPAR genotype, which stood out in relation to the other. The greatest emergencies were obtained with seeds with 36 hours of hydration, and the lowest emergence was found after 72 hours under hydration. Keywords: hydration, safflower, seeds 1. Introduction Looking for alternatives for the production of biodiesel, there is a plant little implemented in Brazil, known as safflower (Carthamus tinctorius L.). This plant has some very interesting characteristics, and the main one is to be adaptable in semi-arid climates, in such a way that it is highly capable of developing and producing satisfactorily in low water availability. Because it has an enormous versatility, this plant has been used since antiquity, being used in the textile dyeing and in the culinary use (Abud et al., 2010). The safflower belonging to the family Asteraceae, is an annual herbaceous plant with possible origin in Asia and Africa. In relation to safflower seeds, it has high quality oil, which can be used for human consumption and industrial use (Abud et al., 2010). The safflower seeds have high oil contents, ranging from 35 to 45%. The oil has high contents of oleic acid (70-75%) and linoleic acid (70-75%) (Dantas et al., 2011; Zanetti et al., 2013). Safflower develops in semi-arid climate (Omidi et al., 2012). However, for safflower as well as for other crops, the water deficit is one of the environmental factors that most affects the agricultural areas, culminating in the decrease of productivity. As a consequence, seed emergence can also be compromised and may delay and even inhibit the emergence of seeds. According to Dantas et al. (2011) emergence is the protrusion stage of one of the parts of the embryo that is associated with some sign of growth, such that this phase occurs with the absorption of water by the seeds, through a process of imbibition of the same.