Nota sobre as exigências minerais do cacaueiro

One kg of dry cocoa beans contains, in grams: N--33.4; P-2.1; K-8.1; Mg-1 .9; S-0.9; in mg: B-12; Cu-16; Fe-80; Mn-28; Mo-0.04; Zn-47. The partially decomposed hulls left in the field showed the following composition on the dry matter basis: N-2.20%; P-0.05; K-2.40; Ca--0.51; Mg-0.32; S-0.12; B-16 ppm; Cu-16; Fe-368; Mn-56; M0-0.06 and Zn-93. Leaves (third from the apex of freshly matured flushing) collected in a high yielding plantation (2.6 t dry beans/ha) showed the following mineral composition: N-1.98%; P-0;17; K-2.20; Ca-0.73; Mg-0.29; S-0.19; B-25 ppm; Cu-14, Fe-87; Mn-134; MO-0.16; Zn-96.Foi feita a determinaçio dos elementos minerais contidos nos frutos do cacaueiro, amêndoas e casca. Um quilo de amendoas secas contêm, em grama: N-33,4; P--2,1; K-8,1; Ca-0,8; Mg-1,9; S-0,9; em mg: B-12; Cu-16, Fe-80; Mn-28; Mo-0,04; Zn-47. A análise completa do casqueiro semi decomposto mostrou na matéria seca os seguintes teores porcentuais N-2,20; P-0,05; K-2,40; Ca-0,51; Mg-0,32; S--0,12; concentração dos micronutrientes, em ppm é B-16; Cu-16; Fe-368; Mn-56; Mo-0,06; Zn-93. Foram colhidas amostras de folhas de uma roça altamente produtiva (172 arrobas ou 2580 quilos//ha)cuja análise mostrou os sequintes teores: N-I ,98%; P-0,17; K-2,20; Ca--0,73; Mq-0,19; B-25 ppm; Cu-14; Fe-87; Mu-134; Mo-0,16; Zn-96

Sobre a composição mineral do aguapé (Eichornia crassipes)

The concentration of macro and micronutrients in roots, stems and leaves of water hyacinth was determined. One kg of the whole plant contains the following quantities of elements: N-10.3g, P-1.6, K-49.0, Ca-25.8, Mg-10.5 and S-3.3; B-25mg, C@-10,436, Co-1.9, Cu-1.2; Fe-8,969, Mn-1,415, Mo-2.3, Ni-4.0 and Zn-41.6. After comparing the composition of water hyacinth with that of stable manure, its use as green manure is discussed.Tendo em vista a utilização do aguapé como adubo verde foram feitas determinações de macronutrientes (N, P, K, Ca, Mg, S) e de micronutrientes (B, Cl, Co, Cu, Fe, Mn, Mo, Ni, Zn) nas raízes, caules e folhas de amostras colhidas na zona rural de Ourofino, MG. Verificou-se que 1kg da planta inteira possui as seguintes quantidades de nutrientes: N-10,3g, P-1,6, K-49,0, Ca-25,8, Mg-10,5 e S-3,3; B-25mg, C@-10436mg, Co-l,9mg, Cu-10,2mg, Fe-8969mg, Mn-1415mg, Mo-2,3mg, Ni-4,0mg e Zn-41,6mg. Fez-se uma comparação entre os nutrientes contidos no aguapé e no esterco de curral e discute-se o seu possível uso como adubo verde, fonte de matéria orgânica e de minerais

Estudos sobre a cinética de absorção do fósforo pelo arroz (Oryza sativa L.) e pelo feijoeiro (Phaseolus vulgaris L.)

Three experiments were conducted under controlled conditions with the objectives of evaluating the effect of different concentrations of phosphorus and on the presence of other ions on the kinetic of absorption. Excised roots of rice and bean were placed in aereated solutions containing increasing concentrations of NaH2PO4 (10-7 M to 5x10-2M) during 90 minutes. The rate of absorption (v = mmols P/g dry matter) and the kinetic constants Vmax and Km were determined. Similar procedure was used to to evaluate the interaction of Mg+2, Al+3, K+, N-NH4+, N-NO3- and N-ureia in the uptake of phosphorus during 120 minutes. In another experiment, the effect of the presence of Mg+2 and/for Al+3 in the uptake and redistribution of phosphorus, was evaluated by varying the external concentration (1 ppm, 5 ppm, 10 ppm and 20 ppm) during a period of 17 hours, and utilizing whole rice plants. It was observed a dual mechanism, with two phases following the Michaelis-Menten kinetics and with transition phase 1 - 50 x 10-5 M. The best explanation of the experimental data was obtained, by transforming the data in accordance with HOFSTEE (1952). Bean was more efficient than rice in the first phase of uptake (higher Vmax). Al+3 had a clear stimulatory effect on the uptake of phosphorus, promoting, however, the anion fixation in the root at lower concentrations. At the highest concentrations (20 ppm) of phosphorus this effect was not evident. No effect on the uptake was observed with Mg+2, K+ and different forms of nitrogen. Urea could have a depressive effect although, not significant. Possible mechanisms invelved are discussed.Objetivando caracterizar os efeitos das diferentes concentrações de fósforo e da presença de outros íons na cinética de absorção de radiofósforo, foram conduzidos ensaios em solução nutritiva, em condições ambientais controladas. Foram empregadas raízes destacadas de arrroz e feijão para os estudos com diferentes concentrações de fósforo no meio (10-7 M até 5 x 10-2 M) e para avaliar as interações promovidas por Mg+2, Al+3, K+, NH4+, N-NO3-, N-urêia no mecanismo de absorção por períodos de uma hora e meia a duas horas. Em plantas inteiras de arroz procurou-se avaliar os efeitos da presença de Mg e/ou alumínio na absorção e transporte de fósforo quando variava a concentração externa (1 ppm, 5 ppm, 10 ppm e 20 ppm) por um período de 17 horas. Foi constatado um mecanismo duplo de absorção com as duas fases seguindo a cinética simples de Michaelis-Menten, e com ponto de transição entre 1-50x10-5. A transformada de dados segundo Hofstee adaptou-se melhor à interpretação dos dados experimentais. Feijão foi mais eficientes na absorção que arroz para a primeira fase (maior Vmax). Alumínio apresentou efeito estimulatório nítido na absorção de fósforo, promovendo porém, a fixação do ânion na raiz quando consideradas as concentrações mais baixas. Em concentrações altas de P, este último efeito não foi evidenciado. Magnésio não promoveu maior absorção, nem maior transporte do que K+; o mesmo aconteceu com as diferentes formas de nitrogênio. Uréia poderia ter um efeito depressivo maior, embora não significativo. Discutem-se os prováveis mecanismos envolvidos nestas respostas

Eficiência relativa de fontes de zinco para o milho (Zea mays L.)

In a Dark Red Latosol, sandy phase, with 0.3 ppm of "available" Zn (Mehlich), the effectiveness of three zinc sources (sulphate, oxide, and fritted-FTE BR-12) was studied in the greenhouse, using corn as a test plant. The following leves of the micronutrient were used: sulphate - 0.0, 0.5, 1.0 and 1.5 ppm, oxide and FTE BR-12 - 1.0 ppm. It was found that the test plant reacted differently to the three sources: sulphate beyond the 1.0 ppm level of supply induced toxicity; although equally efficient in terms of dry matter production, the two insoluble sources did no restrict growth when supplied at the same rate There was a highly significant correlation between Zn applied and taken up. Both DTPA-TEA and Mehlich's solution estimated equally well residual Zn in the soil. The two insoluble sources left in the soil a content of available Zn roughly equal to that found in the intermediate level of sulphate addition. Attention should be drawn to the risk of inducing zinc toxicity when soluble sources are used in sandy soils similar to that employed in the present experiment.Em um solo LEa fase cerrado com 0,3 ppm de Zn disponível (Mehlich) foi avaliada a eficiência relativa do sulfato de zinco, óxido de zinco e frita FTE Br-12 como fontes do elemento para o milho, em condições de casa de vegetação. Foram usados os seguintes níveis, além de uma testemunha sem o micronutriente: sulfato - 0,0; 0,5; 1,0 e 1,5 ppm de Zn; óxido e frita - 1,0 ppm Zn. Verificou-se que o milho respondeu diferentemente às fontes: o sulfato em dose maior que 1,0 ppm Zn, mostrou-se tóxico; além de eficientes no fornecimento de Zn, o óxido e a frita não mostraram tendência para toxidez; houve correlação altamente significativa entre Zn aplicado e absorvido. O teor de Zn residual foi determinado usando-se DTPA e o extrator de Mehlich; houve correlação positiva entre osteores extraídos pelas duas soluções; a solução de duplo ácico forneceu valores maiores; as duas fontes insolúveis deixaram no solo níveis de Zn equivalentes aproximadamente aos encontrados com a dose menor de sulfato. Os níveis de Zn no solo depois da colheita associados à maior produção de matéria seca foram 1,5 e 1,3 ppm, respectivamente para o extrator duplo ácido e para o DTPA-TEA

Estudos sobre a nutrição mineral do cafeeiro: XL. Fitomassa e conteúdo de macro e micronutrientes no material podado

An experiment has carried out in commercial coffee plantation (varie ty Mundo Novo, 7 years old, 1904 "covas" per ha, previous yield 3,180 kg cleancoffe, Ipanema Agro Indústria S.A., Alfenas, MG, Brazil) designed to estimate the quantities of biomass, macro and micronutrients there in, removed by different types of pruning, namely: (1) stumping at 0,40 m above ground;(2) capping at 1,00 m; (3) capping at 1,50 m; (4) capping at 2,00 m; (5) capping at 1,50 m and cutting of laterals at 15 cm from the main stem. Analyses of data and material allowed for the following conclusions to be drawn. (1) Biomass removed by pruning was higher when pruning was done by stumping (24.3 tons of fresh weight and 11.9 tons dry weight) and by capping at 1,00 m above ground (20.6 and 10.1 tons, respectively); these treatments were followed by capping at 1,50 m plus cutting off laterals which yielded 19.4 and 8.3 tons of fresh and dry weight; the fresh and try weight corresponding to capping at 1,50 and 2,00 m above ground were: 12.1 and 5.4, 5.6 and 2.5 tons por hectare. (2) Simple regression equations describe with a high degree of significance the relationship between height of pruning and biomass removed there off. (3) The amount of macro and micronutrients, as expected, relate well with the quantity of plant material which corresponds to each treatment. Total amounts for macronutrients were, according to the order of the treatments given above (in kg/ha): N - 320; 294; 162; 80 and 261; P - 18; 15; 10; 44 and 16; K - 286; 266; 168; 78 and 273; Ca - 149; 139; 63; 33 and 101; Mg - 30; 33; 16; 8 and 26; S - 10; 7; 6; 3 and 10. In the same order, the amounts of micronutrients were, in g/ha: B - 306; 337; 163; 83 and 268; Cu - 229; 219; 121; 51 and 191; Fe - 2783; 2328; 1367; 544 and 2088; Mn - 437; 779; 264; 142 and 412; Zn - 174; 152; 74; 28 and 121. (4) Simple regression equations were derived which express the relationship between quantities of macro and micronutrients removed and the heighth of pruning. (5) Recycling of the biomass curt off fy pruning could contribute to savings in the rates of fertilizer to be applied in the period of regrowth. Most of the nutrients, however, from two thirds to three fourths of the total, are found in branches and stems which is likely to more slonly released.Foi conduzido um ensaio numa plantação comercial de café de variedade Mundo Novo de 9 anos de idade, com uma população de 1904 covas/ha, destinada a avaliar a quantidade de biomassa e de nutrientes removidas por diferentes tipos de poda: recepa a 0,40m; decote a 1,00, 1,50 e 2,00 m; decote a 1,50m com esqueletamento. A análise do material e dos dados permitiu tirar-se as seguintes conclusões: (1) a biomassa removida pela poda foi maior na recepa (24,3 t de matéria fresca e 11,9 de matéria seca) e no decote a 1,00 m (20,6 e 10,1 t, respectivamente); seguia-se o decote a 1,50 m com esqueletamento que deu 19,4 e 8,3 t de matéria fresca e seca por hectare; os pesos da matéria fresca e seca correspondentes aos decotes a 1,50 m e 2,00 m foram: 12,1 e 5,4; 5,6 e 2,5 t/ha; (2) a relação existente entre a altura de poda e quantidade de fitomassa removida é descrita por equações de regressão simples; (3) as quantidades de nutrientes removidas são proporcionais as quantidades de material podado sendo as seguintes de acordo com a ordem dos tratamentos dado, em kg/ha: N - 320, 294, 162, 80 e 261; P - 18, 15, 10, 44 e 16; K - 286, 266, 168, 78 e 273; Ca - 149, 139, 63, 33 e 101: Mg - 30, 33, 16, 8 e 26; S - 10, 7,6, 3 e 10; as quantidades de micronutrientes removidas foram, em g/ha: B - 306, 337, 163, 83 e 268; Cu - 229, 219, 121, 51 e 191; Fe - 2783, 2328, 1367, 544 e 2,088; Mn - 437, 779, 264, 142 e 412; Zn - 174, 152, 74, 28 e 121; (3) foram derivadas equações de regressão simples que relacionam quantidade extraídas e altura da poda; (4) a reciclagem de fitomassa contribui com economia substancial de fertilizantes para a nova vegetação. Cerca de dois terços e três quartos de nutrientes, entretanto, estão contidos no material lenhoso de caules e ramos o que deve fazer que a sua disponibilidade seja mais lenta

Adubos verdes e seus efeitos no rendimento da cana-de-açúcar em sistema de plantio direto.

O objetivo deste trabalho foi avaliar adubos verdes e seus efeitos no rendimento da cana-de-açúcar em sistema de plantio direto (SPD). O trabalho foi realizado em Campos dos Goytacazes (RJ), no período de dezembro de 2003 a julho de 2005. O delineamento experimental foi em blocos casualizados, com quatro repetições. Os tratamentos foram: feijão-de-porco (Canavalia ensiformis), mucuna-preta(Mucuna aterrimum), crotalária (Crotalária juncea) em plantio direto e vegetação espontânea em preparo convencional (testemunha). Com crotalária aos 35 dias após emergência (DAE) houve maior taxa de cobertura do solo – 87% – e, aos 92 DAE produziu 17.852 kg ha-1 de matéria seca, respectivamente, 41%, 78% e 407% superior ao feijão-de-porco, mucuna e vegetação espontânea, além de superá-las em acúmulos de K, Mg, S, Zn e Fe. O feijão-de-porco e a mucuna proporcionaram o maior teor de N na parte aérea. Com feijão-de-porco, os teores de P e Ca foram maiores que a crotalária e a mucuna. Com vegetação espontânea, o maior teor de K foi na parte aérea. As leguminosas acumularam maiores quantidades de N e Cu do que a vegetação espontânea. A crotalária e o feijão-de-porco acumularam 66% a mais de P na parte área que a mucuna. O SPD utilizando a adubação verde contribuiu significativamente para a maior produtividade de cana-de-açúcar, 135.863 kg ha-1, sendo 37% superior ao PC com a vegetação espontânea

PRIMARY HYPERPARATHYROIDISM AND THE PRESENCE OF KIDNEY STONES ARE ASSOCIATED WITH DIFFERENT HAPLOTYPES OF THE CALCIUMSENSINGRECEPTOR

Introduction: Three single-nucleotide polymorphisms in the calcium-sensing receptor gene (CASR) encoding the missense substitutions A986S, R990G, and Q1011E have been associated with normal variation in extracellular calcium homeostasis, both individually and in haplotype combination. The aim of this study was to examine haplotype associations in primary hyperparathyroidism (PHPT). Patients and Methods: Patients with sporadic PHPT (n = 237) were recruited from endocrine clinics and healthy controls (n = 433) from a blood donor clinic, and levels of serum calcium, albumin, and PTH were measured. In PHPT patients, urinary calcium/creatinine clearances and bone mineral density at spine and femoral neck were measured and the presence of kidney stones and vertebral fractures identified. The CASR single-nucleotide polymorphisms were haplotyped by allele-specific sequencing. Results: Four haplotypes (ARQ, SRQ, AGQ, and ARE) of eight were observed, in keeping with significant linkage disequilibrium, but haplotype frequencies did not show significant Hardy-Weinberg disequilibrium. The SRQ haplotype was more common in PHPT (125 of 474 alleles) than in controls (170 of 866 alleles, P = 0.006) and showed a significant (P = 0.006) gene-dosage effect. There was no significant association between haplotype and bone mineral density or fractures, but association with kidney stones was significant (P = 0.0007). In the stone-forming subgroup, the SRQ haplotype was underrepresented and AGQ overrepresented. Patients bearing the AGQ haplotype had an odds ratio of 3.8 (95% confidence interval, 1.30-11.3) for presentation with renal stones compared with the rest. Conclusion: Our data indicate that the CASR SRQ haplotype is significantly associated with PHPT in our population. Within the PHPT patient population, the AGQ haplotype is significantly associated with kidney stones

Primary hyperparathyroidism and the presence of kidney stones are associated with different haplotypes of the calcium-sensing receptor

Introduction: Three single-nucleotide polymorphisms in the calcium-sensing receptor gene (CASR) encoding the missense substitutions A986S, R990G, and Q1011E have been associated with normal variation in extracellular calcium homeostasis, both individually and in haplotype combination. The aim of this study was to examine haplotype associations in primary hyperparathyroidism (PHPT). Patients and Methods: Patients with sporadic PHPT (n = 237) were recruited from endocrine clinics and healthy controls (n = 433) from a blood donor clinic, and levels of serum calcium, albumin, and PTH were measured. In PHPT patients, urinary calcium/creatinine clearances and bone mineral density at spine and femoral neck were measured and the presence of kidney stones and vertebral fractures identified. The CASR single-nucleotide polymorphisms were haplotyped by allele-specific sequencing. Results: Four haplotypes (ARQ, SRQ, AGQ, and ARE) of eight were observed, in keeping with significant linkage disequilibrium, but haplotype frequencies did not show significant Hardy-Weinberg disequilibrium. The SRQ haplotype was more common in PHPT (125 of 474 alleles) than in controls (170 of 866 alleles, P = 0.006) and showed a significant (P = 0.006) gene-dosage effect. There was no significant association between haplotype and bone mineral density or fractures, but association with kidney stones was significant (P = 0.0007). In the stone-forming subgroup, the SRQ haplotype was underrepresented and AGQ overrepresented. Patients bearing the AGQ haplotype had an odds ratio of 3.8 (95% confidence interval, 1.30-11.3) for presentation with renal stones compared with the rest. Conclusion: Our data indicate that the CASR SRQ haplotype is significantly associated with PHPT in our population. Within the PHPT patient population, the AGQ haplotype is significantly associated with kidney stones