Navegando por Autor "Giuriatto Júnior, Jurandyr José Ton"

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Clonal cutting production by Coffea canephora mother plants under increasing nitrogen doses
(Universidade Federal de Viçosa, 2024-12-16) Kolln, Alana Mara; Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento de; Campanharo, Marcela; Rocha, Rodrigo Barros; Giuriatto Júnior, Jurandyr José Ton
This study aimed to establish production curves of cuttings for Coffea canephora coffee plants in response to nitrogen doses. A clonal garden of the botanical variety Robusta was used to evaluate the effects of seven nitrogen doses divided into four applications. The subplots corresponded to two evaluation periods: January and June 2019. The following traits were evaluated: number of stems, number of viable cuttings, number of cuttings per stem, cutting fresh and dry mass, and cutting macronutrient contents. The results showed that C. canephora produced a higher amount of vegetative mass and propagules during the period from September to January compared to the period from January to June. Nutrient concentrations in the tissues varied with the period of the year due to soil nutrient availability and the amount of accumulated dry mass. Increasing nitrogen doses resulted in higher vegetative and propagules mass associated to higher nitrogen and potassium concentrations in the cuttings; but had no effect on phosphorus, calcium, magnesium, and sulfur contents. Nutrient contents in the cuttings followed the order K>N>Ca>P>Mg>S regardless of the applied nitrogen dose.
Growth and physiological quality in clonal seedlings of Robusta coffee
(Universidade Federal do Ceará, 2020) Giuriatto Júnior, Jurandyr José Ton; Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento de; Vasconcelos, Jaqueline Martins; Campanharo, Marcela
The intrinsic characteristics of the vegetative propagule may influence the rooting speed and shoot growth, as well as the final physiological quality of clonal seedlings of Coffea canephora. The aim of this study was to evaluate the growth and physiological quality of ‘Robusta’ coffee seedlings produced from propagules (stem cuttings) with different cutting ages. The study was conducted in a greenhouse, in the district of Ouro Preto do Oeste, in Rondônia, Brazil (10˚45’43” S and 62˚15’10” W). The ages of the cuttings were 30, 60, 90, 120 and 150 days, corresponding to five positions on the secondary orthotropic stem (sprout), from the apex to the base. Dry matter accumulation, and relative and absolute growth rates were evaluated for 188 days after cutting, as well as the vegetative characteristics of the seedlings at 125 days after cutting. It appears that growth can be divided into three phases: 1) Initial: slow growth, lasting approximately 83 days; 2) Intermediate: fast growth, lasting approximately 40 days; and 3) Final: slow growth, starting approximately 125 days after cutting. With physiological quality, although all the cuttings showed similar growth curves, those of 60, 90 and 120 days produced, 125 days after cutting, the best vegetative performance in the seedlings.
Nutrient content and cutting anatomy can affect the production of Conilon clonal plantlets
(Editora UFLA, 2024-09-19) Bazoni, Patricia Alves; Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento de; Vasconcelos, Jaqueline Martins; Giuriatto Júnior, Jurandyr José Ton; Campanharo, Marcela
Cutting is the main vegetative propagation method used to produce Coffea canephora plantlets. In this method, the nutritional quality of the vegetative propagule (stem cuttings) is one of the determining factors for the rooting speed and the final quality of the plantlets. Thus, the objective in this study was to verify possible variations in nutrient content and anatomical characteristics in cuttings collected at different times of the year and their relationship with the production of Coffea canephora clonal plantlets. The study was divided into two phases: 1) Nutritional composition and anatomy of C. canephora cuttings grown at different times; 2) Production of C. canephora seedlings under greenhouse conditions. The treatments consisted of cuttings collection and plantlets production at different times of the year: January, May and September 2017. We observed that there is seasonal variation for the content of N, P, K and Mg; and anatomical changes in xylem, phloem and vascular cylinder thickness in cuttings harvested at different times of the year. We conclude that although nutritional and anatomical aspects of the vegetative propagule may result in different vegetative growth rates of C. canephora clonal plantlets, this result is more dependent on the management of the nursery environment conditions, especially temperature and relative air humidity.