Physiological quality of Tithonia diversifolia (Hemsl.) A. Gray seeds as a function of harvest period and storage conditions

Eduardo Pacca Luna Mattar1, Tiago Teixeira Vianna2, Wander Douglas Pereira2, Bruno Portela Brasileiro3, Paulo Cesar Hilst2, Denise Cunha Fernandes dos Santos Dias2
1 Federal University of Acre, Rio Branco, Acre 69920-900, Brazil 
2 Federal University of Viçosa, Department of Plant Science. Viçosa, Minas Gerais 36570-900, Brazil
3 Federal University of Paraná, Department of Plant Science and Phytosanitation. Curitiba, Paraná 80060-000, Brazil


Mattar, E. (2019). Physiological quality of Tithonia diversifolia (Hemsl.) A. Gray seeds as a function of harvest period and storage conditions. Bulgarian Journal of Agricultural Science, 25 (6), 1133–1142

Tithonia diversifolia is a shrub of the Asteraceae family native to Central America and found on all continents. It has multiple functions with emphasis on use in animal feed and as a medicinal plant. It is usually propagated vegetative, with little information on seed propagation. For this reason, the aim of this study was to define the ideal time for harvesting the seeds and to evaluate the quality of the seeds according to time and storage condition. Therefore, achenes were collected on different days after the anthesis (14, 16, 18, 20, 22, 24, 28, 32, 36 and 40 days) of inflorescence. Following harvesting, the following variables were evaluated: seed dry matter mass, germination percentage, germination speed index, germination speed and percentage of full achenes. Moreover, these variables were analyzed as a function of two storage conditions (refrigerated and non-refrigerated environment) and two storage times (6 and 12 months). The ideal harvest period comprised the period from 28 to 36 days after anthesis, in which seeds with germination percentages exceeding 75% and percentage of full achenes of 100% were obtained. The chilled environment provided the highest percentages of seed germination. Moreover, germination speed increased throughout the storage time. The seeds showed a high percentage of germination after 12 months of storage, both in refrigerated and non-refrigerated conditions.

Keywords: Asteraceae; medicinal plant; Mexican sunflower; multipurpose shrub; non-conventional forage; seed production

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