Egídio Bezerra Neto

Indução de resistência a Fusarium oxysporum f. sp. Tracheiphilum em Caupi: eficiência de indutores abióticos e atividade enzimática elicitada

The effect of abiotic inducers in two cowpea cultivars inoculated with Fusarium oxysporum f.sp. tracheiphilum (E. F. Smith) Snyder & Hansen was evaluated in relation to severity, disease control and enzyme activity. Aqueous solution of ASM (5.0 mg/mL), BABA (1.5 mM) or chitosan (2.0 mg/mL) was sprayed on the first pair of leaves of five-day-old cowpea plants, cultivars BR-17 Gurgueia and IPA-206. After seven days of elicitor application, inoculation was carried out with 20 mL of a 1 x 106 conidia/mL suspension of the ISO-PE isolate. Plants were harvested at five and 10 days after inoculation, and the activity of phenylalanine ammonia lyase (PAL), b-1.3-glucanase and peroxidase was analyzed. Significant difference between treatment with inducers and control was verified, mainly for ASM which provided a disease control of 68.9% and 71.59% for BR-17 Gurgueia and IPA-206 cultivars, respectively. ASM showed the best results related to b-1.3-glucanase, peroxidase and PAL and activities, especially for the cultivar IPA-206 five or 10 days. BABA and chitosan differed from the control for PAL and b-1.3-glucanase activity on cultivar IPA-206, five days after inoculation.

Development and mineral composition of corn as a function of soil compaction and application of organic compost

The objective of the this study was to evaluate the effect of organic compost and compaction levels of two soils on shoot dry weight and macronutrient contents of corn (Zea mays), cultivar Itapoa 700. In 54 pots, three doses of the processed organic compost residue from Recife Central Market were applied in two soils, one being a dark red Argissoil (DRA) and the other a yellow red Argissoil (YRA), collected in Ap horizon (0 to 0.20 m depth) and under three compaction levels in a factorial arrangement 2 × 3 × 3 with three replications. Shoot dry matter and N, P, K, Ca and Mg contents were evaluated. The results indicate that soil compaction does not affect corn growth. The organic compost application increased K and Ca but decreased Mg content in shoots. Calcium content in corn shoot increased with the organic compost in DRA soil, but was found to decrease in YRA soil.

Ponto de murcha permanente fisiológico e potencial osmótico de feijão caupi cultivado em solos salinizados

Com o objetivo de avaliar o ponto de murcha permanente fisiologico, a umidade foliar e o potencial osmotico no feijoeiro caupi, sob duas condicoes de estresses (salino e salino + hidrico), foram conduzidos dois experimentos em casa de vegetacao na Universidade Federal Rural de Pernambuco (Recife, PE, Brasil). O delineamento experimental adotado foi o inteiramente casualizado, em arranjo fatorial 2 x 4, sendo duas classes texturais de solos (franco-arenoso e franco-argiloso) e quatro niveis de salinidade do solo, equivalentes as condutividades eletricas do extrato de saturacao do solo 4, 8 e 12 dS m

Comportamento hídrico e crescimento do feijão vigna cultivado em solos salinizados

Soil salinization reduces the capacity of plants to absorb water, and in general causes decrease in plant growth. Plant responses to salt stress are better correlated with osmotic potential compared to electrical conductivity of soil saturation extract. In order to evaluate the effect of salt stress on growth, water use and leaf osmotic potential of cowpea [Vigna unguiculata L. (Walp.)], an experiment was carried out in a greenhouse of the Federal Rural University of Pernambuco (Recife-PE, Brazil). The Treatments were in a factorial arrangement of 2 x 4, comprising of two soil textures and four levels of soil salinity (4, 8 and 12 dS m-1 at 25 °C, and the control without salt addition) with five replications. It was concluded that soil salinity causes reduction in water consumption, leaf osmotic potential, plant height, number of leaves and dry biomass of shoot of cowpea.

Produção e nutrientes minerais de milheto forrageiro e sorgo sudão adubado com soro de leite

Este estudo objetivou avaliar o desenvolvimento e teores de macronutrientes presentes no milheto e no sorgo Sudao, em resposta a aplicacao de doses de soro de leite ao solo. O experimento foi conduzido com solo em vasos com capacidade de 8 dm3 em ambiente protegido utilizando-se delineamento inteiramente casualizado em arranjo fatorial 2 (aplicacao unica e parcelada) x 5 (doses de soro) com quatro repeticoes. As doses foram equivalentes a: 0, 167, 333, 667 e 1000 m3 ha-1 de soro de leite, determinadas com base no teor de K. O soro foi aplicado em dose unica, 10 dias antes da semeadura e em dose parcelada (50% 10 dias antes da semeadura e 50% 20 dias apos a emergencia das plantas). Apos 42 dias realizou-se a colheita e se determinaram altura e massa seca da parte aerea. A trituracao da massa seca foi realizada para o preparo de extratos, com vista as determinacoes analiticas dos nutrientes, P, Na, K, Ca e Mg. Os resultados mostraram que para producao de massa seca no manejo de aplicacao dose unica ocorreu, a partir da dose equivalente a 667 m3 ha-1 de soro de leite, diminuicao na producao, em ambas as culturas, enquanto para a aplicacao parcelada a reducao se deu a partir da dose 167 m3 ha-1.

Nutrientes minerais em pimentão fertirrigado sob lâminas de irrigação e doses de potássio

The aim of this study was to evaluate the macronutrient concentrations in leaves and fruits of sweet pepper plants subjected to irrigation depths and potassium doses by fertigation. The experimental design was completely randomized in factorial scheme 5x2, with four replications, the factors being five water depths (80, 90, 100, 110 and 120% of ETc) and two potassium doses (80 and 120 kg ha-1 of K2O) parceled according to phenological phase. The fertirrigation was made by a drip irrigation system, with self-compensable emitters, installed in a battery of 40 drainage lysimeters cultivated with sweet pepper plants (Hybrid Maximos F1), located at the Federal Rural University of Pernambuco (UFRPE) in Recife, Pernambuco state, Brazil, whose experimental plot consisted of three plants in each lysimeter. The results showed the following order of nutrients content: N>K>Cl>Mg>Ca>P>S>Na, in the leaves, and K>N>Cl>P>Ca>S>Mg>Na, in the fruits. The highest concentrations of K and Mg in the leaves were obtained with the water depths of 103.43 and 105.54% of crop evapotranspiration, respectively; the K doses did not inhibit the absorption of nutrients, except for Mg and S in the leaves.

Desenvolvimento inicial do milho submetido à adubação com manipueira

This research aimed to evaluate the effect of cassava wastewater fertilization on maize growth. The experiment was carried out under greenhouse conditions at the Federal Rural University of Pernambuco (Brazil). Treatments were assigned in a factorial arrangement 5 x 3, being 5 cassava wastewater doses: 0, 12.6, 25.2, 50.4 and 75.6 m3 ha-1 and 3 harvest ages: 20, 40, and 52 days after germination (DAG), in a completely randomized design, with four replications. A hybrid of forage maize (AG 1051) was used, keeping one plant in a 20 L pot. The variables evaluated were: plant height, stalk diameter, number of leaves, dry and fresh matter of leaves and stalks. The dose equivalent to 63 m3 ha-1 provided the highest gain in stalk diameter, number of leaves, dry and fresh matter of leaves; while the dose equivalent to 75.63 m3 ha-1 provided significant increase in the other evaluated phenological parameters. Cassava wastewater presented as a useful fertilization source for maize crop, however responses depended on utilization of appropriated cassava wastewater doses.

Desempenho de cultivares de alface em cultivo hidropônico sob dois níveis de condutividade elétrica

. Os tratamentos foram as cultivares de alface Baba de Verao, Floresta, Luisa, Manoa, Regina 579, Saia Veia e Vitoria Verdinha. O delineamento experimental foi blocos casualizados, com tres repeticoes. A colheita foi feita aos 45 dias apos a semeadura. Nenhuma cultivar se destacou no conjunto das caracteristicas avaliadas, embora a Manoa tenha apresentado o maior indice de queima de bordas das folhas, sem diferir estatisticamente da Saia Veia e Baba de Verao. As cultivares Regina 579 e Vitoria Verdinha sao as preferidas dos produtores hidroponico de Pernambuco, devido a falta de genotipos mais adaptados a essa modalidade de cultivo, e por apresentarem folhas lisas, levemente enrugadas e de textura macia.

Efeito do composto orgânico e compactação do solo no milho e nutrientes do solo

When well utilized, organic residues lead to great benefits making organic matter and nutrients available in soils. In this context, the present study had the objective to evaluate the effect of organic compost doses on two soils submitted to different compactions and on corn biomass. Thus, in 54 pots were added three doses 0, 40 or 80 g dm-3 of organic compost in a Dark Red Argisoil or Red Yellowish Argisoil, collected from the Ap horizon (depth of 0 to 0.20 m), submitted to three compaction degrees (1.3, 1.5 and 1.7 kg dm-3), with three replications. The crop used in the experiment was corn (Zea mays), cultivar Itapua 700. The plant growth, and content of N, P, K, Ca, Mg and organic carbon (TOC) in soil were evaluated. The results point out that the organic compost application significantly affected soil OC and macronutrients, but little effect was induced by the soil compaction on these variables.

Crescimento e nutrição mineral de milho forrageiro em cultivo hidropônico com soro de leite bovino

Realizou-se este trabalho com o objetivo de avaliar a eficiencia nutricional da forragem de milho e a utilizacao do soro de leite bovino em substituicao a solucao nutritiva no cultivo de forragem hidroponica de milho. O experimento foi conduzido em casa de vegetacao em delineamento experimental inteiramente casualizado, com seis tratamentos e cinco repeticoes, sendo o tratamento controle representado por solucao nutritiva convencionalmente empregada nesse tipo de cultivo; os demais tratamentos foram distribuidos em diferentes niveis de diluicao (20, 40, 60, 80 e 100%) do soro de leite em agua potavel. A colheita foi feita 15 dias apos a germinacao, separando-se a biomassa da parte aerea da biomassa do substrato com as raizes. Determinaram-se a massa fresca e seca, os teores de macronutrientes (N, P, K, Ca, Mg e S) e micronutrientes (Fe, Cu, Zn e Mn), alem dos elementos em niveis toxicos (Na e Cl), tanto da parte aerea como do sistema radicular. O aumento nas concentracoes de soro de leite promoveu reducao na produtividade da forragem hidroponica, acrescimo nos teores de N, S e Zn, estabilidade no teor de K e reducao do Ca e Mg, nao apresentando efeito nos teores de P, Fe e Cu, na parte aerea, enquanto nas raizes ocorreu acrescimo nos teores de P, K, Ca, Mg, S e Cu.