Nutrição mineral do mamoeiro (Carica papaya L.): III - sintomatologia de carências nutricionais

Objetivando caracterizar as deficiências de N, P, K, Ca, Mg e S em mamoeiro (Carica papaya L.) em condições de casa de vegetação e soluções nutritivas, desenvolveu-se o presente trabalho. Os autores descrevem os sintomas de carência dos macronutrientes, com exceção do enxofre, cujas plantas que receberam o tratamento deficiente neste nutriente, não mostraram sintomas, provavelmente por contaminação externa. Os níveis analíticos encontrados em folhas sadias e desnutridas, expressos em função da matéria seca foram: N-4,24% e 3,61%; P-0,52% e 0,14%; K-3,81% e 1,36%; Ca-1,29% e 0,28%; Mg-0,65 e 0,17%.

Nutrição mineral do mamoeiro (Carica papaya L.): V. marcha de absorção de nutrientes em condições de campo

A presente pesquisa foi conduzida em condições de campo, no município de Botucatu - SP, em um solo pertencente ao grande grupo - Terra Roxa Estruturada e de clima Cf.b. Este trabalho teve como objetivo estudar a marcha de absorção dos seguintes nutrientes: N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn. Dentre os resultados obtidos constatouse que: a - a absorção de nutrientes pela parte aérea é crescente durante o primeiro ano da cultura, atingindo absorção máxima no décimo segundo mês. b - em cultura de um ano, a absorção de nutrientes pela parte aérea, por planta, obedece a seguinte ordem: N - 66,7g; K - 62,8g; Ca 24,8g; Mg - 10,3g; S - 7,3g; P - 6,3g; Fe - 229,8 mg; Mn - 149,lmg; Zn - 79,7mg B - 74,2mg; Cu - 20,0mg; Mo - 0,15mg.

Nutrição mineral de plantas ornamentais XI: deficiências de macronutrientes e de boro em Catharanthus Roseus (L.) G. Don e Catharanthus roseus f. albus (sweet) G. Don

Plantas de duas formas botânicas de Catharanthus roseus, de flores lilases e de flores brancas foram cultivadas em soluções nutritivas deficientes em N, P, K, Ca, Mg, S e B, e em solução completa, a fim de se obter o quadro sintomatológico das deficiências, assim como os níveis analíticos de nutrientes nas folhas, caules, raízes e flores. Manifestaram-se sintomas de deficiência claros para todos os nutrientes estudados. Nas plantas de flores lilases, as concentrações de nutrientes na matéria seca de folhas de plantas normais e deficientes foram, respectivamente, para cada nutriente estudado: N(%): 3,53-1,20; P(%): 0,35-0,11; K(%): 2,45-0,76; Ca(%): 1,77-0,81; Mg(%): 0,55-0,46; S(%):0,21-0,12; B(ppm): 382-37. Nas plantas de flores brancas, estas concentrações foram: N(%): 3,78-0,92; P(%): 0,38-0,09; K(%): 2,60-0,86; Ca(%): 1,37-1,15; Mg(%): 0,56-0,44; S(%): 0,10-0,07; B(ppm):372-39.

Crescimento radicular e nutrição mineral da soja em função da calagem e adubação fosfatada

Tanto o cálcio como o fósforo tem importante ação no crescimento de raízes. No presente trabalho foi estudado, em vasos, o efeito de tres níveis de Ca e quatro níveis de P no crescimento radicular, produção de matéria seca e nutrição de plantas de soja cv. IAC 17. Duas plantas foram cultivadas em cada vaso de 7 L, preenchidos com terra proveniente de um Latossolo Vermelho Escuro de textura média, por 35 dias. Foi efetuada calagem calculada para se atingir saturações do solo por bases de 45, 50 e 75 %. As doses de P foram 25, 50, 100 e 200 mg kg-1, utilizando-se de fonte de P isenta de Ca. O teor de 8,5 mmol(c) dm-3 de Ca no solo foi suficiente para o crescimento normal do sistema radicular da soja. A baixa disponibilidade de P, em saturação do solo por bases de 46%, induziu ao crescimento das raízes em comprimento e superfície, sem modificar a massa de matéria seca das raízes. Embora raízes finas e longas tenham geometria favorável à absorção de P, em parcelas com teores menores que 45 mg kg-1, este ajuste não é suficiente para manter a mesma absorção que é observada em parcelas com maior disponibilidade do nutriente.

Selenato e selenito na produção, nutrição mineral e biofortificação com selênio em cultivares de alface

SELENATE and SELENITE on YIELD, MINERAL NUTRITION and BIOFORTIFICATION WITH SELENIUM IN LETTUCE CULTIVARSSelenium is an important antioxidant element associated with physiological processes in plants, microorganisms, animals, and humans. However, its mode of action and essentiality in plants are still disputed. In Brazil, information on Se in agricultural crops is extremely scarce, though there are indications that low levels of Se are being consumed by the population. The objective of this study was to evaluate the effect of selenate and selenite on yield, mineral nutrition and biofortification with Se of lettuce cultivars. The experiment was arranged in a completely randomized factorial design 5 x 3 x 2, with five lettuce cultivars (Maravilha de Verao, Rafaela, Great Lakes, Veneranda, and Vera), three Se concentrations (0, 10 and 20 mu mol L(-1)) and two forms of Se (selenate and selenite), with four replicates. Results indicate that selenate application is more appropriate for biofortification of lettuce cultivars, while the effect of selenite proved to be more toxic. The application of selenate results in increased S shoot concentrations, while selenite reduced P concentrations, and both Se forms decreased micronutrient concentrations. No genotypic variation among lettuce cultivars was observed for Se concentration, and little variation was observed for shoot dry matter yield and S, Mg, Mn, and Fe levels.

Efeitos da nutrição mineral na competição inter e intraespecífica de Eucalyptus grandis e brachiaria decumbens: 1- crescimento

The present work was conducted with the objective to study the effects of mineral nutrition on Eucalyptus grandis and Brachiaria decumbens (#BRADC) growth, when submitted to inter- and intra-specific competition. The treatments consisted of two plants of Eucalypts/pot, two plants of BRADC/pot, and one plant of each species/pot. The plants were nourished with the Hoagland e Arnon (1950) complete solution; with no K, P or N; or only with either N, P or K. Sixty days after growing side by side, no effect of the inter- and intra-specific competition on eucalypts plant high, branch number and leaf dry mass was observed. When mineral nutrition did not limit plant growth (complete solution or solution with no K), intra-specific competition reduced on average, 23% of eucalypts root length, leaf area, and stem and root dry mass, and inter-specific competition reduced, on average, 75% of BRADC dry mass. When mineral nutrition became a limiting factor, no plant competition effect on the parameters studied was detected.

Crescimento radicular e nutrição mineral de cultivares de feijão em resposta à calagem

Pós-graduação em Agronomia (Agricultura) - FCA

Doses crescentes de nitrogênio, fósforo, potássio e diferentes níveis de saturação por bases em relação ao desenvolvimento e nutrição mineral de Teca (Tectona grandis L. F.), sob condições de vaso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nutrição mineral e produtividade da batata-doce biofortificada em função de doses de fósforo e potássio

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Nutrição mineral e escleromorfismo foliar de grupos funcionais e comunidades vegetais savânicas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Calagem, adubação e nutrição mineral de Anonáceas

Among the edaphic factors, those related to acidity are the ones that affect productivity, especially in tropical regions. For culture the Annonaceae, no research results that indicate the proper base saturation, nor the determination of doses, times, application methods and sources of nutrients for orchards Annonaceae in training and production in order to promote sustainability and higher yields. Given the importance and potential of commercial exploitation of Annonaceae in Brazil and, considering the limited available scientific information on liming, fertilization and nutrition of fruit plants of this family, some research has to be carried out urgently due to the effects of nutrients on productivity, fruit quality, post-harvest, tolerance to pests and diseases, etc.

Crescimento e nutrição mineral de Sida rhombifolia

This experiment was carried out to analyze dry mass production and distribution, and the content and accumulation of macronutrients in arrowleaf sida (Sida rhombifolia) plants cultivated under mineral nutrition standard conditions. Plants grew in seven liter pots filled with sand substrate and daily irrigated with nutrient solution, under greenhouse conditions. Treatments consisted of times of evaluation (21, 35, 49, 63, 77, 91, 105, 119, and 133 days after emergence - DAE) and were arranged in a completely randomized design with four replicates. Arrowleaf sida plants showed small accumulation of dry mass (0.3 g per plant) and macronutrients (6.9 mg N per plant, 0.7 mg P per plant, 8.6 mg K per plant, 4.9 mg Ca per plant, 2,6 mg Mg per plant, and 0.3 mg S per plant) at the vegetative growth stage (< 49 DAE). Those accumulations increased, mainly after 63 DAE, and the daily accumulation rate was crescent up to 94 DAE (dry mass - DM), 89 DAE (N and P), 98 DAE (K), 95 DAE (Ca and S), and 93 DAE (Mg), when there was accumulation of 26.3 g DM per plant, 402.6 mg N per plant, 45.6 mg P per plant, 359.3 mg K per plant, 337.6 mg Ca per plant, 71.9 mg Mg per plant, and 20.9 mg S per plant. N and K had the highest rates and, consequently, were the most required and accumulated in greater amounts in plant tissues of arrowleaf sida.

Coberturas vegetais, manejo do solo, doses de nitrogênio e seus efeitos na nutrição mineral e nos atributos agronômicos do milho

Research has investigated the best nitrogen rate for maize under the most diverse types of soil management. The aim of this study was to evaluate the influence of cover crops, soil management and topdressed N rates on the dry matter production, nutritional status, plant lodging, plant height and first-ear insertion of maize. Field experiments were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, at 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, to test combinations of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage system) and N rates (0, 60, 90 e 120 kg ha-1 - urea as source). The maize hybrid DKB 350 YG® was used and topdressing N applied at stage V5 (fifth expanded leaf). Previously grown sunn hemp and millet + sunn hemp resulted in a higher shoot dry matter, P leaf content and total N, P and K uptake. In the no-tillage system, the initial and final population and shoot dry were highest, and first-ear insertion and plant height lower. The application of 120 kg ha-1 topdressed N increased the P leaf content, N and P in the entire plant, shoot dry matter, total N, P and K uptake, plant height, and the first-ear insertion of maize.

Nutrição mineral e qualidade do fruto de algumas frutíferas tropicais: goiabeira, mangueira,bananeira e mamoeiro

Fruit quality is the result of the action of several factors, in particular the individual and combined effect of mineral nutrients. The proper evaluation of mineral nutritional requirements causes that fruit plants can express all their genetic potential. Thus, a research has been conducted in tropical fruit, for evaluating the influence of mineral nutrients on fruit quality; however, they appear dispersed. The objective of this review was to compile and report the effects of mineral nutrients on fruit quality of guava, mango, banana and papaya. Consequently, information about the influence of the essential elements in color, flavor, shape, size, appearance, penetration resistance, physiological disturbs disease incidence, physicochemical characteristics and lifetime of post - harvest fruit are presented.

Crescimento e nutrição mineral de Urochloa arrecta

The experiment was carried out aiming to analyze dry mass production and distribution, and the content and accumulation of macronutrients in Urochloa arrecta plants cultivated under mineral nutrition standard conditions. Plants grew in seven-liter pots filled with sand substrate, were daily irrigated with nutrient solution, and maintained under greenhouse conditions. Treatments corresponded to assessment periods (21, 35, 49, 63, 77, 91, 105, 119, 133, 147, and 161 days after emergence - DAE) and were arranged in a completely randomized design with four replicates. Plants of U. arrecta showed low accumulation (less than 7% of the maximum accumulation at 161 DAE) of dry mass (5.1 g DM per planta) and of macronutrients (57.7 mg N per planta, 8.9 mg P per planta, 167.8 mg K per planta, 21.3 mg Ca per planta, 14.7 mg Mg per planta, and 9.2 mg S per planta) up to 49 DAE. Such accumulations increased mainly after 91 DAE. Daily accumulation rate was crescent up to 130 DAE (DM and S), 137 DAE (N), 125 DAE (P), 119 DAE (K), 144 DAE (Ca), and 128 DAE (Mg), when there was accumulation of 87.7 g DM per planta, 918.0 mg N per planta, 105.8 mg P per planta, 1,643.9 K per planta, 390.4 mg Ca per planta, 200.0 mg Mg per planta, and 103.5 mg S per planta. K and N were found to have the highest rates and, hence, they were the most demanded and accumulated in the greatest amounts in U. arrecta plant tissues.