Effects of nutrient foliar sprays containing growth regulators on productivity of peanut (Arachis hypogaea L. cv. Tatu-53)

The effects of the application of a macronutrient foliar spray combined with micronutrients and growth regulators (Unifol) on peanut grown in a soil with high fertility were investigated. A control without fertilizer and a soil fertilization (250 kg/ha) with NPK 9-30-16 were also established. Other treatments were as follows: Unifol fertilizer (18-12 16) applied 23 days after germination: Unifol (18-12-6) applied at the beginning of flowering; Unifol (18-12-6) applied during flowering, and Unifol (18-12-6) applied 23 days after germination plus Unifol (7-23-7) at the beginning of flowering. No significant differences were found amongst treatments, but certain treatments showed higher productivity e given Unifol fertilizer (18-12-6) applied 23 days after germination plus Unifol (7-23-7) at the flower anthesis. In this treatment, the number of pods, weight of seeds and production of seeds were higher. Best production of forage occurred in the treatment receiving soil fertilization.

Available content, surface runoff and leaching of phosphorus forms in a typic hapludalf treated with organic and mineral nutrient sources

The application of animal manure to soil can increase phosphorus availability to plants and enhance transfer of the nutrient solution drained from the soil surface or leached into the soil profile. The aim of this study was to evaluate the effect of successive applications of organic and mineral nutrient sources on the available content, surface runoff and leaching of P forms in a Typic Hapludalf in no-tillage systems. Experiment 1 was set up in 2004 in the experimental area of UFSM, in Santa Maria (RS, Brazil). The treatments consisted of: control (without nutrient application) and application of pig slurry (PS), pig deep-litter (PL), cattle slurry (CS), and mineral fertilizers (NPK). The rates were determined to meet the N crop requirements of no-tillage black oat and maize, grown in the 2010/2011 growing season. The soil solution was collected after each event (rain + runoff or leaching) and the soluble, particulate and total P contents were measured. In November 2008, soil was collected in 2 cm intervals to a depth of 20 cm, in 5 cm intervals to a depth of 40 cm, and in 10 cm intervals to a depth of 70 cm. The soil was dried and ground, and P determined after extraction by anion exchange resin (AER). In experiment 2, samples collected from the Typic Hapludalf near experiment 1 were incubated for 20, 35, 58, 73 and 123 days after applying the following treatments: soil, soil + PS, soil + PL, soil + CS and soil + NPK. Thereafter, the soil was sampled and P was analyzed by AER. The applications of nutrient sources over the years led to an increase in available P and its migration in the soil profile. This led to P transfer via surface runoff and leaching, with the largest transfer being observed in PS and PL treatments, in which most P was applied. The soil available P and P transfer via surface runoff were correlated with the amounts applied, regardless of the P source. However, P transfer by leaching was not correlated with the applied nutrient amount, but rather with the solution amount leached in the soil profile.

Assessment on nutrient levels in the aerial biomass of irrigated guava in São Francisco Valley, Brazil

In perennial crops, fertilizers are applied to restore the amount of nutrient removed from the plant by harvesting. Nevertheless, the immobilized nutrient inside the whole plant should be considered. Based on it, the nutrient concentrations in the guava leaf and fruit and the nutrient contents removed by fruits and post-harvest pruning were evaluated in an irrigated orchard, in Petrolina, State of Pernambuco, Brazil. The greatest contents removed by fruits were N and K among the macronutrients, while Fe, Zn and Mn presented higher levels among the micronutrients. More than 60% of the total content of N, P, K, Mg, Fe, and B removed by pruning were immobilized in the leaf and non-marketable fruit.

Adubação foliar com silício na cultura do milho

Inúmeros trabalhos têm demonstrado o efeito benéfico da adubação com silício sobre o acréscimo da produção de diversas culturas, como, por exemplo, arroz, cana-de-açúcar e batata. No entanto, são escassas as informações sobre os benefícios nutricionais do silício para a cultura do milho. Desta maneira, objetivou-se, neste estudo, avaliar o efeito de doses e épocas de aplicação de silício, via foliar, nas características agronômicas e na produtividade do milho, cultivado no ano agrícola 2007/2008. O delineamento experimental adotado foi o de blocos casualizados, em esquema fatorial (4 x 3) + 1, com quatro repetições, envolvendo doses de silício (130, 260, 390 e 520 g ha-1 de Si) aplicadas via foliar, épocas de aplicação (2, 5 e 8 folhas expandidas) e uma testemunha (sem aplicação de Si). As variáveis analisadas foram altura das plantas e a inserção da primeira espiga, diâmetro de colmo, índice de clorofila foliar, teor foliar de silício, número de grãos por espiga, massa de 100 grãos e produtividade de grãos. O silício aplicado via foliar influenciou somente o teor foliar de Si.

Foliar and Radicular Absorption of Boron by Beetroot and Tomato Plants

The isotopic technique was employed to study boron (B) mobility in tomato and beetroot plants under protected cultivation conditions. An experiment was conducted in which both species grew in 10-dm3 vases filled with coconut fiber, under hydroponic conditions. The plants were subjected to four different treatments: (1) no B in the substratum and no foliar fertilization; (2) no B in the substratum, with foliar 10B fertilization; (3) B in the substratum, with foliar 10B fertilization; and (4) 10B in the substratum and no foliar fertilization. The biological growth variables and total B and 10B contents in the plant parts grown after the application of the nutrient were evaluated. For increasing B content in young tissues, the foliar application of this element was not as efficient as application via root system, indicating low mobility of B in the tissues of both beetroot and tomato plants. © 2013 Copyright Taylor & Francis Group, LLC.

Aplicação foliar de doses de molibdênio em soja: características agronômicas, teor de molibdênio e qualidade fisiológica das sementes

Pós-graduação em Agronomia - FEIS

Aplicação de sistemas neuro-fuzzy e espectrometria no infravermelho próximo para a identificação em tempo real do teor de nitrogênio foliar em cana-de-açúcar

Pós-graduação em Engenharia Elétrica - FEB

OPTIMUM RATIO OF CALCIUM AND BORON IN THE NUTRIENT SOLUTION OR IN CASTOR BEAN SHOOT FOR FRUIT YIELD AND SEED OIL CONTENT

Calcium (Ca) and boron (B) have been reported as the major macro-and micronutrient required for castor bean plant yield. The objective of this study was to determine the Ca: B ratios (in the growth media and plant tissue) for fruit yield and shoot dry weight of the castor bean (Ricinus communis L.), grown in a nutrient solution, and to evaluate Ca and B supply on concentration and total uptake of Ca, potassium (K), magnesium (Mg), and B, as well on the seed oil content. The treatments were arranged in a 3 x 3 factorial fashion, consisting of three rates of Ca (40, 80, and 160 mg L-1) and three of B (0.32, 0.96, and 1.60 mg L-1). Calcium and B rates increased the shoot and root dry weight and fruit yield at a Ca: B ratio in the nutrient solution of 166 and 100, respectively. Symptoms of B deficiency were observed in plants supplied with 0.32 mg B L-1, regardless of the Ca concentration in the nutrient solution. Plants which showed visual symptoms of Ca deficiency cultivated with 40 mg Ca L-1 presented concentration of Ca in plant tissue up to 10 g kg(-1). The concentration and total Ca and B uptake increased with the rates of them. Notwithstanding, the shoot Ca accumulation was improved by B rates. In addition, there were no decreases in K and Mg uptake due to Ca rates. Furthermore, addition of 80 mg L-1 of Ca and 1.60 mg L-1 of B in the growth media increased the seed oil content. The Ca: B ratio in the diagnostic leaf associated with the highest plant dry weight (shoot and root) and fruit yield, was 500 (16 to 20 g kg(-1) of Ca, and for 30 to 40 mg kg(-1) of B).

Absorption and mobility of foliar-applied boron in soybean as affected by plant boron status and application as a polyol complex

In the present study (i) the impact of plant Boron (B) status on foliar B absorption and (ii) the effect of B complexation with polyols (sorbitol or mannitol) on B absorption and translocation was investigated. Soybean (Glycine max (L.) Meer.) plants grown in nutrient solution containing 0 μM, 10 μM, 30 μM or 100 μM 11B labelled boric acid (BA) were treated with 50 mM 10B labelled BA applied to the basal parts of two leaflets of one leaf, either pure or in combination with 500 mM sorbitol or mannitol. After one week, 10B concentrations in different plant parts were determined. In B deficient leaves (0 μM 11B), 10B absorption was significantly lower than in all other treatments (9.7% of the applied dose vs. 26%–32%). The application of BA in combination with polyols increased absorption by 18–25% as compared to pure BA. The absolute amount of applied 10B moving out of the application zone was lowest in plants with 0 μM 11B supply (1.1% of the applied dose) and highest in those grown in 100 μM 11B (2.8%). The presence of sorbitol significantly decreased the share of mobile 10B in relation to the amount absorbed. The results suggest that 11B deficiency reduces the permeability of the leaf surface for BA. The addition of polyols may increase 10B absorption, but did not improve 10B distribution within the plant, which was even hindered when applied a sorbitol complex.

Influence of crude protein content, ingredient complexity, feed form, and duration of feeding of the phase I diets on productive performance and nutrient digestibility of Iberian pigs.

The influence of CP content and ingredient complexity, feed form, and duration of feeding of the Phase I diets on growth performance and total tract apparent digestibility -TTAD- of energy and nutrients was studied in Iberian pigs weaned at 28 d of age. There were 12 dietary treatments with 2 type of feeds -high-quality, HQ; and low-quality, LQ-, 2 feed forms -pellets vs. mash-, and 3 durations -7, 14, and 21 d- of supply of the Phase I diets.

Estimating nutrient intake in comparative studies of animals: an example using dietary carotenoid content in birds

Many different methods of reporting animal diets have been used in ecological research. These vary greatly in level of accuracy and precision and therefore complicate attempts to measure and compare diets, and quantitites of nutrients in those diets, across a wide range of taxa. For most birds, the carotenoid content of the diet has not been directly measured. Here, therefore, I use an avian example to show how different methods of measuring the quantities of various foods in the diet affect the relative rankings of higher taxa (families, subfamilies, and tribes), and species within these taxa, with regard to the carotenoid contents of their diets. This is a timely example, as much recent avian literature has focused on the way dietary carotenoids may be traded off among aspects of survival, fitness and signalling. I assessed the mean dietary carotenoid contents of representatives of thirty higher taxa of birds using four different carotenoid intake indices varying in precision, including trophic levels, a coarse-scale and a fine-scale categorical index, and quantitative estimates of dietary carotenoids. This last method was used as the benchmark. For comparisons among taxa, all but the trophic level index were significantly correlated with each other. However, for comparisons of species within taxa, the fine-scale index outperformed the coarse-scale index, which in turn outperformed the trophic level index. In addition, each method has advantages and disadvantages, as well as underlying assumptions that must be considered. Examination and comparison of several possible methods of diet assessment appears to highlight these so that the best possible index is used given available data, and it is recommended that such a step be taken prior to the inclusion of estimated nutrient intake in any statistical analysis. Although applied to avian carotenoids here, this method could readily be applied to other taxa and types of nutrients.

Foliar phosphorus application enhances nutrient balance and growth of phosphorus deficient sugarcane

Although it is well known that nutrient imbalance in shoot tissues may impair plant performance, the interactive effect between foliar phosphorus (P) application and varying P availability in the rooting medium on the nutritional status of sugarcane has not been well studied. To fill this research gap, four sugarcane varieties (IAC91-1099, IACSP94-2101, IACSP94-2094 and IACSP95-5000) were evaluated using a combination of two concentrations of P in nutrient solution (P-deficient, PD = 0.02 mmol L^(−1) and P-sufficient, PS = 0.5 mmol L^(−1)) and foliar P application (none and 0.16 mol L^(−1)). The spray was applied until drip point three times during the experiment with 15 days intervals, after which the plants were harvested to quantify growth and shoot concentration of nitrogen (N), P, magnesium (Mg), sulphur (S) and manganese (Mn). The responses of sugarcane plants to foliar P spray at different levels of P supply in the rooting medium was not genotype-dependent. It was demonstrated for the averaged values across varieties, that foliar P application enhanced sugarcane performance under low P, as revealed by improvements of leaf area and dry matter production of shoot and root of PD plants. Under P limitation we also observed diminished shoot concentration of N, P, Mg, S and increased concentration of Mn. However, foliar P spray increased the concentrations of N, P, S and reduced shoot Mn. Furthermore, shoot P:N, P:Mg, P:S, P:Mn and Mg:Mn concentration ratios exhibited a positive relationship with shoot dry matter production. In conclusion, low P supply in the rooting medium impairs nutrient balance in shoot tissues of sugarcane at early growth; however, this effect was ameliorated by foliar P application which merits further study under field conditions.

Deleterious effect of TRIS buffer on growth rates and pigment content of Gracilaria birdiae Plastino & E.C. Oliveira (Gracilariales, Rhodophyta)

This work evaluated the effects of Tris (hydroxymethyl)-aminomethane (TRIS) buffer and its interaction with nutrient concentration on the development of Gracilaria birdie, a common species on the Brazilian coast that has been exploited for agar production. Responses to different conditions were assessed through growth rates and pigment content (chlorophyll a, phycoerythrin, phycocyanin and allophycocyanin). Provasoli's nutrient solution with and without TRIS addition was tested at concentrations of 12.5, 25 and 50%. The pH was also monitored. G. birdiae grew better in the absence of TRIS and at low nutrient concentrations, 12.5 and 25% (growth rates of 10.8-11.3%.day-1). Higher contents of phycoerythrin and chlorophyll a were observed without TRIS at 12.5 and 25% (Phycoerythrin, 649.6-698.0 μg g-1 fresh biomass; Chlorophyll a, 156.0-168.6 μg g-1 fresh biomass). These findings highlight the deleterious effect of TRIS on growth and phycoerythrin and chlorophyll a content. They also demonstrate the importance of appropriate nutrient concentration for laboratory cultures, depending on the intrinsic characteristics of each species.

Functional specialization of Eucalyptus fine roots: contrasting potential uptake rates for nitrogen, potassium and calcium tracers at varying soil depths

1. Little is known about the role of deep roots in the nutrition of forest trees and their ability to provide a safety-net service taking up nutrients leached from the topsoil. 2. To address this issue, we studied the potential uptake of N, K and Ca by Eucalyptus grandis trees (6 years of age - 25 m mean height), in Brazil, as a function of soil depth, texture and water content. We injected NO(3)(-)- (15)N, Rb(+) (analogue of K(+)) and Sr(2+) (analogue of Ca(2+)) tracers simultaneously in a solution through plastic tubes at 10, 50, 150 and 300 cm in depth in a sandy and a clayey Ferralsol soil. A complete randomized design was set up with three replicates of paired trees per injection depth and soil type. Recently expanded leaves were sampled at various times after tracer injection in the summer, and the experiment was repeated in the winter. Soil water contents were continuously monitored at the different depths in the two soils. 3. Determination of foliar Rb and Sr concentrations and (15)N atom % made it possible to estimate the relative uptake potential (RUP) of tracer injections from the four soil depths and the specific RUP (SRUP), defined as RUP, per unit of fine root length density in the corresponding soil layer. 4. The highest tracer uptake rates were found in the topsoil, but contrasting RUP distributions were observed for the three tracers. Whilst the RUP was higher for NO(3)(-)- (15)N than for Rb(+) and Sr(2+) in the upper 50 cm of soil, the highest SRUP values for Sr(2+) and Rb(+) were found at a depth of 300 cm in the sandy soil, as well as in the clayey soil when gravitational solutions reached that depth. 5. Our results suggest that the fine roots of E. grandis trees exhibit contrasting potential uptake rates with depth depending on the nutrient. This functional specialization of roots might contribute to the high growth rates of E. grandis trees, efficiently providing the large amounts of nutrients required throughout the development of these fast-growing plantations.