Efficiency and response of conilon coffee clones to phosphorus fertilization

Studies on nutritional efficiency of phosphorus in conilon coffee plants are important tools to unravel the high limitation that natural low levels of this nutrient in soil impose to these species cultivars. Therefore, this study aimed at evaluating the nutritional efficiency and the response to phosphorus of conilon coffee clones. Plants were managed during 150 days in pots containing 10 dm³ of soil, in greenhouse. A factorial scheme 13 x 2 was used, with three replications, being the factors: 13 clones constituting the clonal cultivar "Vitória Incaper 8142" and two levels of phosphate fertilization (0% and 150% of the P2O5 usualy recommended), in a completely randomized design (CRD). The results indicate a differentiated response of dry matter production and of phosphorus content on each level of phosphate fertilization for the conilon coffee clones and that CV-04, CV-05 and CV-08 clones are nutritionally efficient and responsive to the phosphate fertilization.

Effect of filler content on morphology and physical-chemical characteristics of poly(vinylidene fluoride)/NaY-zeolite filled membranes

Poly(vinylidene fluoride) electrospun membranes have been prepared with different NaY zeolite contents up to 32%wt. Inclusion of zeolites induces an increase of average fiber size from ~200 nm in the pure polymer up to ~500 nm in the composite with 16%wt zeolite content. For higher filler contents, a wider distribution of fibers occurs leading to a broader size distributions between the previous fiber size values. Hydrophobicity of the membranes increases from ~115º water contact angle to ~128º with the addition of the filler and is independent on filler content, indicating a wrapping of the zeolite by the polymer. The water contact angle further increases with fiber alignment up to ~137º. Electrospun membranes are formed with ~80 % of the polymer crystalline phase in the electroactive  phase, independently on the electrospinning processing conditions or filler content. Viability of MC3T3-E1 cells on the composite membranes after 72 h of cell culture indicates the suitability of the membranes for tissue engineering applications.

Estimação da área foliar por método não destrutivo, utilizando medidas lineares das folhas de espécies de Passiflora

Objetivou-se, com este trabalho, desenvolver uma equação confiável, que possibilite calcular a área foliar de forma rápida e não destrutiva, utilizando medidas lineares da folha, para as diferentes espécies de Passiflora (P. alata, P. coccinea, P. gibertii, P. ligularis, P. misera, P. mucronata, P. nitida, P. setacea). Foram coletadas trezentas folhas, de diferentes tamanhos, de cada espécie. Realizaram-se análises de regressão da área foliar versus comprimento da nervura principal, maior largura da folha e o produto destas. A área foliar foi medida com um dispositivo de medição automática e as medidas lineares foram determinadas utilizando-se régua. O modelo linear escolhido, para todas as espécies, foi o que utiliza o produto das variáveis independentes, por apresentar maior coeficiente de determinação (R²) e maior significância do coeficiente de regressão. Os modelos apresentaram coeficiente de determinação ajustado superior a 0,927 e índice de desempenho ótimo, segundo a classificação de Camargo e Sentelhas. No processo de validação do modelo, mostrou-se que a correlação da área foliar medida com a área foliar observada foi muito alta. Os resultados obtidos neste estudo demonstram que a área foliar das espécies de Passifloras podem ser preditas, usando-se as determinações do comprimento e da largura das folhas.

Efeito da aplicação foliar de silicato de potássio e de fungicida na severidade da ferrugem da folha e da mancha amarela do trigo

A ocorrência de doenças, como a ferrugem da folha (Puccinia triticina) e a mancha amarela (Drechslera tritici-repentis), pode reduzir a produtividade do trigo. O objetivo deste trabalho foi avaliar o efeito da aplicação foliar de silicato de potássio (SP) e de fungicidas, no controle da ferrugem da folha e da mancha amarela, nos cultivares de trigo Safira e Quartzo. Utilizou-se o delineamento experimental em blocos casualizados, no esquema de parcelas subdivididas e com quatro repetições. Os cultivares foram alocados nas parcelas e, nas subparcelas, os tratamentos: T1 - testemunha, T2 - fungicida (azoxistrobina 60 g i.a./ha + ciproconazol 24 g i.a./ha) foram aplicados nos estádios 45 (final da elongação) e 58 (espigamento); T3 - SP (40 g/L), aplicado nos estádios 45 e 58 ; T4 - SP (40 g/L), aplicado no estádio 45, e fungicida aplicado no estádio 58; T5 - hidróxido de potássio (6,5 g/L) foi aplicado nos estádios 45 e 58. O volume de calda utilizado para as pulverizações foi de 250 L/ha. As severidades da ferrugem da folha e da mancha amarela foram avaliadas, a partir dos sete dias, após a primeira pulverização de SP e de fungicida, e, depois, a cada semana, totalizando cinco avaliações. Os dados foram utilizados para calcular a área abaixo da curva do progresso da ferrugem da folha (AACPFF) e a área abaixo da curva do progresso da mancha amarela (AACPMA). O SP, nas doses e número de aplicações avaliadas, não foi eficiente na redução da AACPMA e da AACPFF, nos dois cultivares.

Leaf area and epicuticular wax content of Sida spp

Morpho-physiological characteristics and chemical composition are directly related to superior competitive ability of crops. This study intended to make a comparative analysis of dry matter production, leaf area and amount of epicuticular wax of three species of Sida spp: S. urens L., S. rhombifolia L. and S. spinosa L. Plants were collected at three growth stages: V1: stage described as up to 10 fully expanded leaves; V2: between 11 leaves and flowering; and R: after flowering. At stages V2 and R, the highest number of leaves was recorded for S. rhombifolia, followed by S. spinosa at V2 and S. urens at R. These results were relatively proportional to leaf area for all species. S. spinosa at the vegetative stage produced the highest values of specific leaf area (SLA), with no significant differences between species at the stage R. The amount of wax per unit of leaf area between species at the same developmental stage was significantly different only at the reproductive stage, where S. spinosa produced 23.18 and 6.23 fold more wax than S. urens and S. rhombifolia respectively. Between the growth stages of each species, there was decrease in the amount of wax with plant age and increase in leaf area (AFE), number of leaves and dry matter. The leaves of the Sida species exhibit different characteristics and this information can be used to optimize the use of herbicides in the control of these weeds.

Adubação foliar com níquel e molibdênio no feijoeiro comum cv. Ouro Vermelho

O objetivo deste trabalho foi avaliar o efeito da aplicação foliar de níquel (Ni) e molibdênio (Mo) sobre componentes de rendimento, crescimento e composição mineral do feijoeiro comum Ouro Vermelho. O delineamento experimental foi o de blocos casualizados, com quatro repetições e arranjo fatorial 5 x 2, constituído de doses de Ni (0, 15, 30, 45 e 60 g ha-1) e de Mo (0 e 80 g ha-1), aplicadas por via foliar, aos 25 dias após a semeadura, na forma de cloreto de níquel hexaidratado e de molibdato de amônio, respectivamente. As doses de Ni não influenciaram os teores foliares de N, P, K, Fe, Mo e Ni, aumentaram, porém, os teores de N, Ni e de proteína bruta na semente. A aplicação foliar de Mo reduziu os teores foliares de P, Fe e Ni, aumentou, no entanto, o teor foliar de Mo e o teor de N, Mo e de proteína bruta na semente. Observou-se que as doses de Ni e de Mo não afetaram a massa de sementes, o número de sementes por vagem, o número de vagens por planta e a massa seca de raiz do feijoeiro. A aplicação de Mo aumentou em 21,62% o número de nódulos.

Nutrient accumulation and biomass production of alfafa after soil amendment with silicates

Studies on the use of silicate correctives in agriculture show that they have great potential to improve soil chemical characteristics, however, little information is available on the reactivity rates of their particle-size fractions. This study investigated whether the reactivity rates obtained experimentally could be considered in the calculation of ECC (effective calcium carbonate) for soil liming, promoting adequate development of alfalfa plants. Six treatments were evaluated in the experiment, consisting of two slag types applied in two rates. The experimental ECC was used to calculate one of the rates and the ECC determined in the laboratory was used to calculate the other. Rates of limestone and wollastonite were based on the ECC determined in laboratory. The rates of each soil acidity corretive were calculated to increase the base saturation to 80%. The treatments were applied to a Rhodic Hapludox and an Alfisol Ferrudalfs. The methods for ECC determination established for lime can be applied to steel slag. The application of slag corrected soil acidity with consequent accumulation of Ca, P, and Si in alfalfa, favoring DM production.

Phytomass production and nutrient accumulation by green manure species

Green manuring is recognized as a viable alternative to improve nutrient cycling in soils. The aim of this study was to evaluate the phytomass production and nutrient accumulation in shoots of the summer green manures jack bean [Canavalia ensiformis (L.) DC.], dwarf pigeon pea (Cajanus cajanvar var. Flavus DC.), dwarf mucuna [Mucuna deeringiana (Bort) Merr] and sunn hemp (Crotalaria juncea L.), under nitrogen fertilization and/or inoculation with N-fixing bacteria. A split plot design was arranged with the four Fabaceae species as main plots and nitrogen fertilization (with and without) and inoculation with diazotrophic bacteria (with and without) as the subplots, in a 2² factorial. The experiment was arranged as a randomized complete block design with four replications. In the conditions of this trial, the sunn hemp had the highest production of shoot phytomass (12.4 Mg ha-1) and nutrient accumulation, while the dwarf mucuna had the lowest production of shoot phytomass (3.9 Mg ha-1) and nutrient accumulation. The results showed no effect of nitrogen fertilization or inoculation with N-fixing bacteria on the production of shoot phytomass and nutrient accumulation, except for inoculation without nitrogen fertilization, resulting in greater P accumulation (p <0.05) in the sunn hemp and greater Zn and Mn accumulation in the dwarf mucuna. These findings indicate that N fertilization or inoculation with N2-fixing bacteria for Fabaceae are low efficiency practices in the edaphoclimatic conditions of this study.

Characterization of verdete rock as a potential source of potassium

Potassium is a nutrient found at low levels in Brazilian soils, requiring large inputs of fertilizers to achieve satisfactory crop yields. Brazil has high external dependence and limited reserves of soluble K mineral, which is traditionally exploited for the production of fertilizers. On the other hand, it is common the occurrence in the country of potassium-rich silicate minerals which are not commercially exploited. This study aimed to characterize mineralogically and chemically samples of verdete rock separated into size fractions and evaluate its potential as potassium fertilizer. The mineral composition of verdete rock is based on glauconite, quartz and feldspar. The total K2O content in verdete rock ranged from 5.18 to 9.0 dag/kg. The K content extracted in water or 2% citric acid was 2.4% below the total of K, indicating low reactivity of verdete rock and limitations for direct use as K source. The processes of physical fractionation and sedimentation in water are inefficient to promote the concentration of K in the different verdete rock fractions. The total K content in some samples are considerable and may enable the use of this rock as raw material for production of more reactive potassium fertilizers.

A aplicação foliar de molibdênio na fase de enchimento de vagens do feijão-comum pode reduzir a qualidade da semente

Com o objetivo de aprimorar a tecnologia de produção de sementes ricas em molibdênio (Mo), foram avaliados os efeitos da aplicação foliar de 600 g ha-1 de Mo na qualidade fisiológica da semente de feijão. Em campo, essa dose de Mo foi aplicada na fase V4 (terceira folha trifoliolada), ou parcelada de duas a quatro vezes e aplicada em V4, R6 (floração), R7 e, ou, R8 (enchimento de vagens). A aplicação de 300 g ha-1 de Mo em R6 não influenciou a qualidade da semente, em comparação com a do controle (90 g ha-1 de Mo aplicado em V4). Dos três tratamentos em que 200, 255 ou 300 g ha-1 de Mo foram aplicados em R7, apenas com 255 g ha-1 o Mo reduziu a germinação e vigor das sementes, em comparação com as do controle. Quando 200, 255 ou 300 g ha-1 de Mo foram aplicados em R8 (cinco tratamentos), geralmente o Mo reduziu a germinação e, em dois casos, também o vigor das sementes, em comparação com os do controle. Concluiu-se que 255 g ha-1 de Mo aplicado em R7 e, sobretudo, doses iguais ou mais altas que 200 g ha-1 de Mo aplicadas em R8 podem reduzir a qualidade fisiológica da semente de feijão.

Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index), electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

Decomposition of ground biomass of secondary forest and yield of annual crops in no tillage

ABSTRACT The objective of this work was to evaluate the dynamics of decomposition process of chopped secondary forest system, previously enriched with legumes Inga velutina Willd. and Stryphnodendron pulcherrimum (Willd.) Hochr. and the contribution of this process to the nutrient input to the cultivation of corn and bean under no-tillage. The experimental design was a randomized block, split plot with four replications. The plots were two species (I. velutina and S. pulcherrimum) and the subplots were seven times of evaluation (0, 7, 28, 63, 189, 252, 294 days after experiment installation). There was no difference (p ≥ 0.05) between the secondary forest systems enriched and no interaction with times for biomass waste, decomposition constant and half-life time. The waste of S. pulcherrimum trees had higher (p < 0.05) C/N ratio than that I. velutina. However, this one was higher (p < 0.05) in lignin content. Nevertheless, the dynamics of residue decomposition was similar. The corn yield was higher (p < 0.05) in cultivation under I.velutina waste. Meanwhile, the beans planted after corn, shows similar (p > 0.05) yield in both areas, regardless of the waste origin.

Adubação potássica aplicada na axila foliar e no solo em coqueiro anão verde

RESUMO O potássio (K) influencia diretamente a produtividade do coqueiro anão por ser ativador de enzimas envolvidas na respiração e fotossíntese, entre outras funções. No entanto em muitos casos sua aplicação no solo não tem proporcionado teores foliares adequados. Avaliou-se a influência de níveis de adubação potássica, com KCl, no solo e na axila foliar, nos teores de nutrientes em coqueiro anão verde (Cocos nucifera L.). O experimento foi conduzido, de 31/05/2007 a 31/05/2008, em pomar comercial, em Campos dos Goytacazes, em Neossolo Quartzarênico Órtico típico, no delineamento experimental em blocos casualizados, com cinco tratamentos e 16 repetições. Os tratamentos consistiram em duas formas de aplicação (no solo e na axila da folha 9) e dois níveis de KCl (1666 e 3333 g de KCl por planta, por ano), níveis 1 e 2 no solo e (833 e 1666 g planta-1 ano-1), níveis 1 e 2 na axila, parceladas em quatro aplicações sendo uma a cada três meses, além de uma testemunha sem KCl. Coletaram-se amostras foliares antes da primeira adubação e três meses após cada adubação. A aplicação de KCl proporcionou aumento dos teores foliares de K e de Cl e diminuiu o de Mg. Os teores foliares de N; P; Ca; S; B; Cu; Fe; Mn e Zn não foram influenciados pelos tratamentos. A aplicação de potássio na axila foliar permite maior absorção desse nutriente pelas plantas. A aplicação foliar minimiza as perdas e possibilita reduzir as quantidades de fertilizante potássico aplicadas.

Gradual correction of phosphorus availability in the no-tillage system

ABSTRACT In areas cultivated under no-tillage system, the availability of phosphorus (P) can be raised by means of the gradual corrective fertilization, applying phosphorus into sowing furrows at doses higher than those required by the crops. The objective of this work was to establish the amount of P to be applied in soybean crop to increase content of P to pre-established values at the depth of 0.0 to 0.10 m. An experiment was carried out on a clayey Haplorthox soil with a randomized block experimental design distributed in split-split plot, with four replications. Two soybean crop systems (single or intercropped with Panicum maximum Jaca cv. Aruana) were evaluated in the plots. In addition, it was evaluated four P levels (0, 60, 120 and 180 kg ha-1 P2O5) applied in the first year in the split plots; and four P levels (0, 30, 60 and 90 kg ha-1 P2O5) applied in the two subsequent crops in the split-split plot. Contents of P were extracted by Mehlich-1 and Anion Exchange Resin methods from soil samples collected in the split-split plot. It was found that it is necessary to apply 19.4 or 11.1 kg ha-1 of P2O5, via triple superphosphate as source, to increase 1 mg dm-3 of P extracted by Mehlich-1 or Resin, respectively, in the 0.0 to 0.10 m layer of depth. The soil drain P character decreases as the amount of this nutrient supplied in the previous crops is increased.

Comparison of body fat content and distribution of familial amyloidotic polyneuropathy patients versus healthy subjects

The deposition of amyloid fibers at the peripheral nervous system can induce motor neuropathy in Familial Amiloidotic Polyneuropethy (FAP) patients. This produces progressive reductions in functional capacity. The only treatment for FAP is a liver transplant, followed by aggressive medication that can affect patients' metabolism. To our knowledge, there are no data on body fat distribution or comparison between healthy and FAP subjects, which may be important for clinical assessment and management of this disease. PURPOSE: To analyze body fat content and distribution between FAP patients and healthy subjects. METHODS: Body fat content and distribution were measured through Double Energy X-ray Densitometry (DXA) in two groups. Group 1 consisted of 43 Familial Amyloidotic Polyneuropathy patients (19 males, 32 + 8 Yrs, and 24 females, 37 + 5 yrs), who had liver transplant less than 2 months before. Group 2 consisted of 18 healthy subjects of similar age (8 males, 36 + 7 yrs, and 10 females, 39 + 5 yrs). RESULTS: Healthy subjects showed higher values than FAP patients for: BMI (24,2+2,3kg/m2 vs 22,3+3,8 kg/m2 respectively, p<0,05), % trunk BF (26,21+8,34kg vs 20,78+9,05kg respectively, p<0,05), % visceral BF (24,43+7,97% vs 19,21+9,30% respectively, p<0,05), % abdominal BF (26,63+8,51% vs 20,63+10,35% respectively, p<0,05) abdominal subcutaneous BF (0,533+0,421kg vs 0,353+0,257kg respectively, p=0,05), abdominal BF/BF ratio (0,09+0,02 vs 0,08+0,02 respectively, p<0,05) and abdominal BF/trunk BF ratio (0,19+0,03 vs 0,17+0,03 respectively, p<0,05). CONCLUSIONS: These results showed that FAP patients soon after liver transplantation exhibited a healthier body fat profile compared to controls. However, fat content and distribution varied widely in FAP subjects, suggesting an individualized approach for assessment and intervention rather than general guidelines. Future research is needed to investigate the long term consequences on body fat following liver transplant in this population.