Doses de fósforo no desenvolvimento inicial de cafeeiros em solos com diferentes texturas

Aimed to evaluate phosphorus levels in soils with different textures in coffee. We used factor: 4 (phosphorus levels) x 3 (type of soil) in a randomized block with three replications. Evaluated: height, leaf area, leaf, stem diameter, dry mass of shoot, root, and total absolute growth rate, relative growth rate, leaf area index, leaf area ratio and rate of assimilation net. It was found maximum growth of plants dosing 501-720 g P2O5. No effect of high doses of phosphorus (P) to form plants with higher yield potential.Objetivou-se avaliar altas doses de fósforo em solos com diferentes texturas, na implantação de cafeeiros. Utilizouse fatorial: 4 (doses de fósforo) x 3 (tipos de solo) em DBC, com três repetições. Avaliou-se: altura, área foliar, no folhas, diâmetro de caule, massa seca de parte aérea, raiz, e total, taxa de crescimento absoluto, taxa de crescimento relativo, índice de área foliar, razão de área foliar e taxa de assimilação líquida. Verificaram-se máximos crescimentos das plantas entre doses de 501 a 720 g.pl-1 de P2O5. Há efeito de altas doses de fósforo (P) na formação de plantas com maior potencial produtivo

Épocas de plantio e polímero hidrorretentor no crescimento inicial do cafeeiro

This work aimed to verify the effect of coffee without irrigation of the planting season using the hydro retainer polymer in the initial plant growth. The experimental design was a randomized block, factorial design, with three replicates. The treatments consisted of six planting dates: October, November, December 2012, January, February and March 2013, as well as presence and absence of hydro retainer polymer applied in the planting hole. Two evaluations were carried out, these in July 2013 and January 2014. It was evaluated plant growth and mortality in the field in function of time of planting and the use of hydro retainer polymer as soil conditioner. A higher growth of plants taken to the field at the beginning of the rainy season compared to other periods, showing that the planting season is crucial that formation period in respect of growth and a possible anticipation of production in later years. Regarding the use of the polymer, it was important to reduce the mortality of plants at the end of the rainy season.Objetivou-se, nesse trabalho, verificar o efeito da época de plantio do cafeeiro sem irrigação com a utilização do polímero hidrorretentor no crescimento inicial das plantas. Foi utilizado delineamento em blocos ao acaso, esquema fatorial com três repetições. Os tratamentos foram compostos por seis épocas de plantio: outubro, novembro, dezembro de 2012, janeiro, fevereiro e março de 2013, além de presença e ausência de polímero hidrorretentor aplicado na cova de plantio. Foram realizadas duas avaliações, estas em julho de 2013 e janeiro de 2014. Avaliou-se o crescimento das plantas e a mortalidade em campo, em função da época de plantio e da utilização do polímero hidrorretentor como condicionador de solo. Observou-se maior crescimento das plantas levadas ao campo, no início do período chuvoso, em relação às demais épocas, evidenciando que a época de plantio é determinante nesse período de formação, com relação ao crescimento e a uma possível antecipação de produção em anos posteriores. Quanto ao uso do polímero, esse foi importante para a diminuição da mortalidade das plantas, no final do período chuvoso

Tolerância ao déficit hídrico por cafeeiros produzidos por estaquia e embriogênese somática

The irrigation in coffee plantations is the focus of research for many years, but the new seedling production technologies (somatic embryogenesis and cuttings) have demanded new behavioral studies of these in the field and their water needs. An experiment was carried out in a greenhouse at the Federal University of Lavras, Lavras - MG, Brazil, aiming at to evaluate the tolerance to drought of coffee coming from seedlings produced by somatic embryogenesis and cutting, the culture of the deployment phase. The experimental design was a randomized complete block design with five replicates, factorial 2 x 5 with two types of seedlings produced by somatic embryogenesis and cuttings, and five levels of irrigation, based on the maintenance of soil field capacity 20%, 40%, 60%, 80% and 100%. At 153 days after beginning of the experiment were evaluated foliar contents proline, leaf water potential, plant height, stem diameter, leaf area, dry weight of roots and shoots. It was found that coffee originated from cuttings and somatic embryogenesis positively and increasingly respond to irrigation. It was also found that the field capacity maintained below 74.6% to 100% coffee derived somatic embryogenesis of seedlings and cuttings, respectively, harm the growth and initials development of plants.A irrigação em lavouras cafeeiras é foco de pesquisas há muitos anos, porém as novas tecnologias de produção de mudas (embriogênese somática e estaquia) têm demandado novos estudos de comportamento dessas em campo e suas necessidades hídricas. Um experimento foi conduzido em casa de vegetação, na Universidade Federal de Lavras, Lavras – MG, com objetivo de avaliar a tolerância ao déficit hídrico de cafeeiros oriundos de mudas obtidas por embriogênese somática e estaquia, na fase de implantação da cultura. O delineamento utilizado foi o de blocos casualizados, com cinco repetições, esquema fatorial 2 x 5 sendo dois tipos de mudas, produzidas por embriogênese somática e estaquia, além de cinco níveis de irrigação, baseados na manutenção da capacidade de campo do solo a 20%, 40%, 60%, 80% e 100%. Aos 153 dias após início do experimento foram avaliados os teores foliares de prolina, potencial hídrico foliar, altura de plantas, diâmetro de caule, área foliar, peso seca de raízes e parte aérea. Constatou-se que a umidade ideal do solo para o período de implantação é de 74,6 a 100% da sua capacidade de campo, o que poderá nortear o manejo da irrigação das lavouras formadas com esses tipos de mudas

Critical ranges for leaf nitrogen and potassium levels in coffee fertigated at the production phase1

With the aim of establishing critical ranges for the leaf nitrogen (N) and potassium (K) levels in fertigated coffee crops under production, an experiment was carried out in the experimental area of the Sector for Coffee Cultivation of the Department of Agriculture at the Federal University of Lavras, in Brazil. Treatments consisted of five levels of fertilizer applied through fertigation: 30%, 80%, 130%, 180% and 230% of the recommended amounts of N and K for rainfed coffee grown in Minas Gerais. A randomised block design with four replications was used. Critical ranges for nutrient concentrations in the leaves were established from the results of growth characteristics (plant height and stem diameter), leaf analyses and productivity. The results obtained were: a) nitrogen (g kg-1): 32.39 to 32.40 for January/February; 33.60 to 33.61 for March/April; 27.39 to 27.42 for May/June; 24.23 to 24.24 for July/August; 26.06 to 26.09 for September/October and 26.50 to 26.51 for November/December; b ) potassium (g kg-1): 20.08 to 20.14 for January/February; 17.89 to 17.91 for March/April; 15.93 to 15.96 for May/June; 15.29 to 15.35 for July/August; 16.61 to 16.64 for September/October and 20.58 to 20.64 for November/December

Water-retaining polymer and seedling type when planting irrigated coffee

ABSTRACT The aim of this work was to evaluate the use of a water-retaining polymer on the initial growth of coffee plants for different levels of irrigation and types of seedling. The experiment was set up in pots with a clayey soil, in a greenhouse of the Sector for Coffee Production of the Federal University of Lavras, Brazil. The experiment was arranged in a randomised block design into sub-lots with three replications, giving a total of 48 experimental units. Four levels of irrigation (25%, 50%, 75% and 100% of the available water) were randomly assigned to the lots; the type of seedling (grown in bags or tubes) were randomly assigned to the sub-lots, and the use or not of the water-retaining polymer randomly assigned to the sub-sub-lots. In the treatments with water-retaining polymer, a dilution of 1.5 Kg of polymer to 400 litres of water was used at a dose of 1.5 litres of solution per plant. The following were evaluated at intervals of 60 days during the experiment (360 days from planting): stem diameter, plant height, leaf area, number of leaves and number of plagiotropic branches on the coffee plants. Hydrated water-retaining polymer favoured the growth of coffee plants under an irrigated system. Irrigation resulted in greater plant growth, with the seedlings grown in bags showing more growth than those grown in tubes

Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

ABSTRACT Ammonia volatilization (N-NH3) is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3) losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification) at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0) + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha-1 and band applied. The N-NH3 losses by volatilization and variations of pH (H2O) were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH3 losses by volatilization (average from three applications) was as follows: urea + anionic polymers (35.8%) > conventional urea (31.2%) = urea + S0 + polymers (31.0%) > urea + 0.15% Cu + 0.4 % B (25.6%) > urea + plastic resin (8.6%) = ammonium nitrate (1.0%)

Technologies for Fertilizers and Management Strategies of N-Fertilization in Coffee Cropping Systems to Reduce Ammonia Losses by Volatilization

The aim of this study was to quantify NH3-N losses from conventional, stabilized, slow-release, and controlled-release N fertilizers in a coffee field. The N fertilizers analyzed were prilled urea, prilled urea dissolved in water, ammonium sulfate (AS), ammonium nitrate (AN), urea + Cu + B, urea + adhesive + CaCO3, and urea + NBPT (all with three split applications), as well as blended N fertilizer, urea + elastic resin, urea-formaldehyde, and urea + polyurethane (all applied only once). NH3-N losses (mean of two crop seasons) were statistically higher for urea + adhesive + CaCO3 (27.9% of applied N) in comparison with the other treatments. Loss from prilled urea (23.7%) was less than from urea + adhesive + CaCO3. Losses from urea + NBPT (14.5%) and urea + Cu + B (13.5%) were similar and lower than those from prilled urea. Urea dissolved in water (4.2%) had even lower losses than those treatments, and the lowest losses were observed for AS (0.6%) and AN (0.5%). For the single application fertilizers, higher losses occurred for urea + elastic resin (5.8%), blended N fertilizer (5.5%), and urea + polyurethane (5.2%); and urea-formaldehyde had a lower loss (0.5%). Except for urea + adhesive + CaCO3, all N-fertilizer technologies reduced NH3-N losses compared to prilled urea