Revista Caatinga
URI permanente para esta coleção${dspace.url}/handle/123456789/13104
Navegar
Item Grain yield of coffee plants fertilized with different doses of 20-00-20 NPK formulation under rainfed conditions(Universidade Federal Rural do Semi-Árido, 2021-07-12) Torres, Josemar Dávila; Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento De; Marcolan, Alaerto Luiz; Rocha, Rodrigo BarrosLittle is known about the management of high-yield clonal Coffea canephora in the Amazonian Region, mainly for nutritional aspects and cultivation system efficiency. This study aimed to evaluate the influence of different nitrogen and potassium fertilization rates on coffee grain yield and fertilizer use efficiency of C. canephora trees. An experiment was performed at an experimental field of the Embrapa Rondônia in Porto Velho (RO), Brazil. It was carried out in a split-plot scheme with six doses of 20-00-20 NPK formulation (0; 250; 500; 1,000; 2,000; and 3,000 kg ha-1) and three years of evaluation (2014, 2015, and 2016). An interaction between fertilizer dose and crop year was observed. Fertilizer doses showed an exponential behavior, with maximum yields of 51, 114, and 79 bags ha-1 at 3,000 kg ha-1 in the crop years of 2014, 2015, and 2016, respectively. Such a behavior impacted average and accumulated yields in the three harvest seasons. As for crop year effect within each fertilizer dose, the highest yield was reached in the second harvest after pruning for renewal of orthotropic stems. Moreover, fertilizer use efficiency by plants decreased exponentially, with the highest value at the lowest dose. Increasing doses of 20-00-20 formulation promoted an exponential increase in grain yield but decreased its use efficiency by C. canephora plants. This management also stimulated a strong biannual production.Item Maturation cycle and fruit-to-bean conversion ratios in amazon robusta coffee cultivars(Universidade Federal Rural do Semi-Árido, 2024-12-02) Sousa, Andrey L. B. de; Rocha, Rodrigo B.; Tadeu, Hugo C.; Lopes, Maria T. G.; Espindula, Marcelo C.; Silva, Raniel C. da; Ferreira, Fábio M.This study aimed to characterize the outturn index, field outturn index, uniformity of maturity, and maturation cycle of fifteen Coffea canephora genotypes grown in different environments of the Western Amazon. Conducted in Amazonas (Itacoatiara and Manaus) and Rondônia (Porto Velho), the research evaluated the performance of ten cultivars and five promising genotypes from Embrapa. The genotype × environment interaction was significant, indicating different performance of clones across environments. Genotypic coefficients surpassed environmental ones, indicating a genetic influence on outturn indices and uniformity of maturity. The mean outturn index was 24.68%, and the field outturn index was 22.57%, with Itacoatiara having the highest mean values. The overall mean fruit uniformity of maturity was 63.02%, with Porto Velho achieving the highest mean uniformity value (71.78%). The cultivar BRS1216 exhibited the best performance for outturn indices and provided the highest gain from selection across environments, showing wide adaptability for the outturn index and adaptability to environments favorable for field outturn. Cultivars BRS3210 and BRS3220 achieved more than 82% uniformity of maturity across locations, with BRS3210 adapting to favorable environments and BRS3220 adapting to unfavorable ones. Additionally, BRS3220 had a high mean field outturn index, indicating wide adaptability and high phenotypic stability. The evaluated Amazon Robusta clones and cultivars displayed the expected maturation cycles.Item With different doses of 20-00-20 NPK formulation under rainfed conditions(Universidade Federal Rural do Semi-Árido, 2021) Torres, Josemar Dávila; Espindula, Marcelo Curitiba; Araújo, Larissa Fatarelli Bento de; Marcolan, Alaerto Luiz; Rocha, Rodrigo BarrosLittle is known about the management of high-yield clonal Coffea canephora in the Amazonian Region, mainly for nutritional aspects and cultivation system efficiency. This study aimed to evaluate the influence of different nitrogen and potassium fertilization rates on coffee grain yield and fertilizer use efficiency of C. canephora trees. An experiment was performed at an experimental field of the Embrapa Rondônia in Porto Velho (RO), Brazil. It was carried out in a split-plot scheme with six doses of 20-00-20 NPK formulation (0; 250; 500; 1,000; 2,000; and 3,000 kg ha-1) and three years of evaluation (2014, 2015, and 2016). An interaction between fertilizer dose and crop year was observed. Fertilizer doses showed an exponential behavior, with maximum yields of 51, 114, and 79 bags ha-1 at 3,000 kg ha-1 in the crop years of 2014, 2015, and 2016, respectively. Such a behavior impacted average and accumulated yields in the three harvest seasons. As for crop year effect within each fertilizer dose, the highest yield was reached in the second harvest after pruning for renewal of orthotropic stems. Moreover, fertilizer use efficiency by plants decreased exponentially, with the highest value at the lowest dose. Increasing doses of 20-00-20 formulation promoted an exponential increase in grain yield but decreased its use efficiency by C. canephora plants. This management also stimulated a strong biannual production.