49 results

Mineral nutrition of eucalypt seedlings grown under different irrigation levels and substrates

Jane Luísa Wadas Lopes, Iraê Amaral Guerrini, João Carlos Cury Saad, Magali Ribeiro da Silva

01/Aug/2007

The objective of this work was to evaluate the effects of gross irrigation depths on the nutrient concentration of Eucalyptus grandis seedlings, produced in different substrates. The experiment was carried out in Camará – Mudas Florestais, in Ibaté, São Paulo, in a factorial 5 x 4, with five daily irrigation levels (6, 8, 10, 12 and 14 mm), applied three times a day (at 10 am, 13 pm and 16 pm), on four substrates (FB- coconut fiber; CPV- pine bark […]

Dynamics of calcium and magnesium in leaves and fruits of arabic coffee

Bruno Galvêas Laviola, Hermínia Emilia Prieto Martinez, Ronessa Bartolomeu de Souza, Víctor Hugo Alvarez V.

01/Apr/2007

Knowledge on mineral nutrient dynamics in coffee trees is important to identify the period of greatest nutritional requirement by the plant, allowing the improvement of fertilization techniques. The aim of our research was to study Ca and Mg dynamics in coffee fruits from anthesis to maturation and compare it with the dynamics of the same elements in leaves of productive branch leaves. The experiment was carried out with three Arabic coffee varieties (Catuaí Vermelho IAC-99, Rubi MG-1192 and Acaiá IAC-474-19) […]

Phosphorus deficiency symptoms in soybean

Ciro Antonio Rosolem, Carolina Amaral Tavares

01/Apr/2006

It was observed in an experimental soybean field in Botucatu County (SP), Brazil, that leaves presented yellowish color with purple shades in the leaflets and petioles at grain filling. These symptoms, although not described in soybean, were compatible with general descriptions of phosphorus deficiency. An experiment was conducted in pots with washed sand and nutrient solution to reproduce these symptoms in controlled conditions. Three soybean plants were grown per pot, in an uncontrolled environment. Phosphorus deficiency symptoms were first observed […]

Surface lime application and black oat cover preceding corn and soybean crops under a no-till system

Eduardo Fávero Caires, Fernando José Garbuio, Luís Reynaldo Ferracciú Alleoni, Michel Alexandro Cambri

01/Feb/2006

Cover crop residues mobilize cations and benefit the action of lime applied on the soil surface owing to the release of low molecular weight organic acids from the soluble fraction of residues. However, these effects in no-till system are yet to be confirmed in field studies. A five-year trial was carried out on a no-till dystrophic Rhodic Hapludox in Ponta Grossa, State of Paraná, Brazil, with the aim of evaluating changes in chemical soil attributes, as well as the corn […]

Effect of density and fertilization NPK on heart-of-palm production of peach palm

Kaoru Yuyama, Wanders B. Chávez F., Bianca G. Pereira, Ildelfonso A. Silva

01/Jun/2005

The effect of density and fertilization on heart-of-palm yield of peach palm under field conditions was determined at Yuricam farm, in Rio Preto da Eva counnty, state of Amazonia, Brazil. The experiment was installed in a randomized complete block design. Treatments were arranged in a 3 x 5 factorial scheme with three replicates. Treatments were comprised of the planting density (10,000; 5,000 and 3,333 plants ha-1) and N, P2O5 and K2O doses (0-0-0; 112.5-12.5-90; 337.5-38-270; 225-90-180 and 225-25-180 kg ha-1). The results of the first year […]

Arbuscular mycorrhizae fungi and nutrient contents in five banana cultivars on an Amazonian Oxisol

Arlem Nascimento de Oliveira, Luiz Antonio de Oliveira

01/Jun/2005

The Amazon banana plant is of great socio-economical importance, despite its requirement for high agricultural input in order to obtain good yields. An association with arbuscular mycorrhizae fungi could minimize the crop’s nutritional needs in the poor soils of the Amazon. The present study aimed at verifying how the plant-fungus mycorrhizal symbiosis influences nutrient concentration in five varieties of adult banana plants cultivated in an acid Amazon Oxisol under field conditions. The banana plantation was defficient in macro (Ca, Mg […]

Arbuscular mycorrhizal association and foliar nutrient concentrations of cupuassu (Theobroma grandiflorum) and guaraná (Paullinia cupana) plants in an agroforestry system in Manaus, AM, Brazil

A. N. Oliveira, L. A. Oliveira

01/Dec/2004

Arbuscular mycorrhiza can be important for plant nutrition in acid and low fertility soils such as those of the Amazon. The present study evaluated the mycorrhizal colonization by native arbuscular mycorrhizal fungi (AMF) and nutrient concentrations of cupuassu and guarana leaves in an agroforestry system in Manaus, Amazonas State, Brazil. Ten plants of each species were selected, of which the roots, soil and leaves were sampled during the rainy and dry seasons. Guarana and cupuassu trees presented higher levels of […]

Importance of mass flow and diffusion on the potassium supply to cotton plants as affected by soil water and potassium

R. H. Oliveira, C. A. Rosolem, R. M. Trigueiro

01/Jun/2004

Late season potassium (K) deficiency has been observed quite frequently for cotton crops in the Brazilian cerrado region. One possible reason for such a problem could be the low water availability at this period of the season. Thus, an experiment was conducted in order to quantify the relative contribution of mass flow and diffusion in supplying K to cotton roots, as affected by soil water and K availability. The arable layer of a typic Red Latosol (Haplortox), with 630 mg […]

Changes in soil chemical properties and corn response to lime and gypsum applications

E. F. Caires, M. T. Kusman, G. Barth, F. J. Garbuio, J. M. Padilha

01/Feb/2004

Root growth and crop yield can be affected by chemical modifications of the soil profile owing to lime and gypsum applications. A field trial was carried out on a dystrophic Clay Rhodic Hapludox in Ponta Grossa, Paraná State, Brazil, aiming to evaluate the changes in the chemical soil properties and corn response to lime and gypsum applications at the installation of a no-tillage system. A randomized complete block design was used, with three replications, in a split-plot experiment. The main […]

Changes in chemical soil characteristics and soybean response to lime and gypsum applications in a no-tillage system

E. F. Caires, J. Blum, G. Barth, F. J. Garbuio, M. T. Kusman

01/Apr/2003

There has been an increasing interest to search alternatives for the establishment of crops under no-tillage systems in the southern region of Brazil, opening up new areas without soil disturbance. A field trial was carried out on a dystrophic Clay Rhodic Hapludox in Ponta Grossa, Paraná State, Brazil, from 1998 to 2001, with the aim to evaluate changes in chemical soil characteristics, as well as the soybean response to lime and gypsum applications in a no-tillage system. A completely randomized […]

1 2 3 4 5