Fontes e doses de potássio na produção e qualidade do café proveniente de plantas cultivadas em duas condições edafoclimatológicas
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Data
1999
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Universidade Federal de Lavras
Resumo
Foram conduzidos dois experimentos, sendo um sobre Latossolo Roxo (LR) no município de São Sebastião do Paraíso (MG) e o outro sobre Latossolo Vermelho Amarelo (LV) no município de Patrocínio (MG). ambos em Fazendas Experimentais da EPAMIG com objetivo de avaliar o efeito de fontes e doses de K na produção, nas faixas críticas de nutrientes e na qualidade dos grãos de café beneficiados provenientes de plantas cultivadas em duas condições edafoclimáticas. Usaram-se, em ambos os locais, cafezais da espécie Coffea arabica L.. da cultivar Catuaí Vermelho. linhagem MG-99 com idade de seis anos, no espaçamento 3,5 x 0,7m, com uma planta por cova. O delineamento experimental foi em blocos casualizados no esquema de parcelas subdivididas, utilizando-se três fontes de K: cloreto de potássio (KCI), sulfato de potássio (K2S04) e nitrato de potássio (KN03) nas parcelas e quatro doses de K (O, 100. 200 e 400 kg ha-1) aplicadas nas subparcelas com quatro blocos. Foram avaliados a produção, teores no solo de K (Mehlich 1) e S-SO4-2 (fosfato diácido de cálcio), os teores foliares de N, K, S e Cl e as variáveis qualitativas dos grãos de café beneficiados como: atividade enzimática da polifenoloxidase. índice de coloração.
acidez titulável total, açúcares e compostos fenólicos totais durante quatro safras (1995 a 1998) e nas duas últimas safras (I997 e 1998) foi determinado o ácido clorogênico pelo método do "HPLC", em cada local. Pelos resultados obtidos conclui-se que o cafeeiro respondeu em produção de grãos a aplicação de doses crescentes de K de cada fonte de K em ambos os locais de cultivo. As doses de K para produção máxima foram de 213,9 kg, 226.5 kg e 223,Okg ha-1, respectivamente das fontes KCI, K2S04 e KN03. A dose de K média foi igual a 221,1kg de K ha-1 com produção média de 46,4sacas ha-1. Houve uma seqüência em ordem decrescente de melhores resultados entre as fontes: K2S04 = KN03 > KC1 para produção de grãos. As faixas críticas para o cafeeiro. correspondentes a 90-100% da produção máxima no solo foram de 83,9 - 152,6mg dm-3 para o K e 31,4 - 39,7mg dm-3 para o S-SO4-2. Para teores foliares, as faixas críticas foram para o N de 29,l - 30,5g kg-1, para o K de 15,7 - 17,6g kg-1, para o S de 1,59 - 1,69g kg-1 e para o CI de 1,10 - 2,78g kg-1. Os valores dos parâmetros qualitativos dos grãos de café beneficiados mostraram que a fonte KC1 teve um resposta inferior em termos de qualidade dos grãos em relação às fontes K2S04, e KN03. Estas últimas fontes tiveram melhor resposta quando aplicadas nas condições de São Sebastião do Paraíso do que nas de Patrocínio. Em termos de doses aplicadas, os melhores resultados para qualidade dos grãos foram obtidos com as doses de 200kg de K ha-1 na forma de KC1 e K2S04 e 1OOkg de K ha-1 na forma de KN03.
Two experiments were conducted, one being on Red Dusky Latosol (RDL) in the country of São Sebastião do Paraíso (MG) and the other on Yellow Red Latosol (YE) in the country of Patrocínio (MG), both on the experimental farms of the EPAMIG with the objective of evaluating the effect of sources and doses of K on yield, in the critical ranges of nutrients and processed coffee grain quality from plants cultivated under two edaphoclimatic conditions. I n both the sites, coffee plantations of the cultivar Catuaí Vermelho. line MG - 99, aged six years, at the 3.5 x 0.7m spacing with a plant per hole were utilized. The experimental design was in randomized blocks in the split plot scheme, by utilizing three sources of K: potassium chloride (KC1), potassium sulphate (K2SO4) and potassium nitrate (KNO3) in the plots and four doses of K (0, 100, 200 and 4OOkg.ha-1) applied in the subplots with four blocks. The yield, contents in the soil of K (Mehlich 1) and S-SO4-2 (calcium diacidic phosphate) and leaf contents of N, K, S and CI, the qualitative variables of the processed coffee grains such as: enzyme activity of polyphenoloxidase, coloration index, total titrable acidity, total sugars and phenolic compounds for four crops (1995 to 1998). in each spot and in the last two crops (1997 and 1998) were evaluated, chlorogenic acid by the HPLC method was determined in each place. From the results obtained, it follows that the coffee tree responded in grain yield to the application of increased doses of K from each source of K in both the growing places. The doses of K for maximum yield were of 213.5 kg, 226.5 kg and 223.0 kg há-1, respectively from the sources KC1, K2SO4 and KNO3. The average doses of K were equal to 221.1 kg of K ha-1 with an average yield of 46.4 sacks ha-1. There was a sequence in decreasing order of best results among the sources: K2SO4 = KNO3 > KC1 for grain yield. The critical ranges for coffee trees corresponding to 90 - 100% of the maximum yield in the soil were of 83.9 - 152.6 mg dm-3 for K and 31.4 - 39.7 mg dm-3 for S-SO4-2. To the leaf contents, the critical ranges were for N of 29.1 - 30.5g kg-1, for K of 15.7 - I7.6 g kg-1, for S of 1.59 - 1.69 g kg-1 and for C1 of 1.10 - 2.78 g kg-1. The values of the qualitatitive parameters of the processed coffee grains showed that the source KC1 had a inferior response in terms of quality of the grains in relation to the sources K2SO4 and KNO3. These latter sources had a better response when applied under the conditions of São Sebastião do Paraíso than under those of Patrocínio. In terms of doses applied, the best results for grain quality were obtained with doses of 200 kg bf K há-1 as KC1 and K2SO4 and 100 kg of K há-1 as KNO3.
Two experiments were conducted, one being on Red Dusky Latosol (RDL) in the country of São Sebastião do Paraíso (MG) and the other on Yellow Red Latosol (YE) in the country of Patrocínio (MG), both on the experimental farms of the EPAMIG with the objective of evaluating the effect of sources and doses of K on yield, in the critical ranges of nutrients and processed coffee grain quality from plants cultivated under two edaphoclimatic conditions. I n both the sites, coffee plantations of the cultivar Catuaí Vermelho. line MG - 99, aged six years, at the 3.5 x 0.7m spacing with a plant per hole were utilized. The experimental design was in randomized blocks in the split plot scheme, by utilizing three sources of K: potassium chloride (KC1), potassium sulphate (K2SO4) and potassium nitrate (KNO3) in the plots and four doses of K (0, 100, 200 and 4OOkg.ha-1) applied in the subplots with four blocks. The yield, contents in the soil of K (Mehlich 1) and S-SO4-2 (calcium diacidic phosphate) and leaf contents of N, K, S and CI, the qualitative variables of the processed coffee grains such as: enzyme activity of polyphenoloxidase, coloration index, total titrable acidity, total sugars and phenolic compounds for four crops (1995 to 1998). in each spot and in the last two crops (1997 and 1998) were evaluated, chlorogenic acid by the HPLC method was determined in each place. From the results obtained, it follows that the coffee tree responded in grain yield to the application of increased doses of K from each source of K in both the growing places. The doses of K for maximum yield were of 213.5 kg, 226.5 kg and 223.0 kg há-1, respectively from the sources KC1, K2SO4 and KNO3. The average doses of K were equal to 221.1 kg of K ha-1 with an average yield of 46.4 sacks ha-1. There was a sequence in decreasing order of best results among the sources: K2SO4 = KNO3 > KC1 for grain yield. The critical ranges for coffee trees corresponding to 90 - 100% of the maximum yield in the soil were of 83.9 - 152.6 mg dm-3 for K and 31.4 - 39.7 mg dm-3 for S-SO4-2. To the leaf contents, the critical ranges were for N of 29.1 - 30.5g kg-1, for K of 15.7 - I7.6 g kg-1, for S of 1.59 - 1.69 g kg-1 and for C1 of 1.10 - 2.78 g kg-1. The values of the qualitatitive parameters of the processed coffee grains showed that the source KC1 had a inferior response in terms of quality of the grains in relation to the sources K2SO4 and KNO3. These latter sources had a better response when applied under the conditions of São Sebastião do Paraíso than under those of Patrocínio. In terms of doses applied, the best results for grain quality were obtained with doses of 200 kg bf K há-1 as KC1 and K2SO4 and 100 kg of K há-1 as KNO3.
Descrição
Tese de Doutorado defendida na Universidade Federal de Lavras
Palavras-chave
Café Potássio Fonte Dose Produção Qualidade Faixa crítica Nutriente Solo Folha HPLC Ácido clorogênico
Citação
Silva, Enilson de Barros. Fontes e doses de potássio na produção e qualidade do café proveniente de plantas cultivadas em duas condições edafoclimatológicas. Lavras : UFLA, 1999. 105p. : il. (Tese - doutorado em Agronomia, área de concentração: Solos e Nutrição de Plantas) Orientador: Francisco Dias Nogueira