Ismael de Jesus Matos Viégas

Efeito da omissão de macronutrientes no crescimento, nos sintomas de deficiências nutricionais e na composição mineral em gravioleiras (Annona muricata)

This work had the objective of evaluating the effect of macronutrient omission in growth, symptoms of nutritional deficiency and mineral composition in soursop plants. It was carried out an experiment in greenhouse conditions, using the missing element technique. It was developed a randomized experiment with four repetition and seven treatments being completed (N, P, K, Ca. Mg, S and micronutrients) and with the omission of N, P, K, Ca, Mg and S from a complete solution. Omissions related to all macronutrients affected plant growth in height, diameter and dry matter yield compared to the complete treatment. Based on the contents in g/kg found in leaves, the levels to adequate (complete) and deficient nutrient were defined as following: N = 14,70 and 8,82; P = 0,92 and 0,47; K = 12,35 and 2,62; Ca = 14,11 and 3,44; Mg = 3,59 and 1,09; S = 5,32 and 2,30, respectively.

Efeito da omissão de macronutrientes e boro no crescimento, nos sintomas de deficiências nutricionais e na composição mineral de plantas de camucamuzeiro

Com o objetivo de avaliar o efeito da omissao de macronutrientes e do micronutriente boro no crescimento, nos sintomas de deficiencias nutricionais e na composicao mineral em plantas de camucamuzeiro, conduziu-se experimento em casa de vegetacao, mediante a tecnica do elemento faltante. O delineamento experimental foi o inteiramente casualizado, com quatro repeticoes e oito tratamentos, sendo completo (N, P, K, Ca, Mg, S e micronutrientes) e omissao individual de N, P, K, Ca, Mg, S e B. Os sintomas visuais de deficiencias foram, de modo geral, de facil caracterizacao para todos os nutrientes. Com excecao do fosforo, as omissoes dos demais nutrientes afetaram a producao de materia seca, quando comparados ao tratamento completo. Com base nos teores em g kg-1, dos macronutrientes, e em mg kg-1, do micronutriente boro nas folhas, infere-se em uma primeira aproximacao dos valores adequados (completo), ou seja: 16,9 a 18,2 de N ; 1,2 a 1,9 de P; 5,2 a 6,0 de K; 9,9 a 11,7 de Ca; 1,4 a 3,6 de Mg; 2,4 a 2,8 de S ; 8,4 a 9,5 de B e do deficiente (omissao) , 6,5 a 7,9 de N ; =0,9 de P; =1,7 de K ; 5,4 a 6,5 de Ca; =0,7 de Mg; 0,7 a 1,2 de S e 1,1 a 1,9 de B

Limitações nutricionais para o cultivo de açaizeiro em latossolo amarelo textura média, Estado do Pará

A regiao amazonica apresenta condicoes edafoclimaticas favoraveis ao desenvolvimento de sistemas de cultivos utilizando fruteiras tropicais. O acaizeiro (Euterpe oleracea, Mart.) desponta como uma das especies de grande importância economica para a fruticultura regional. A producao de fruteiras ainda e limitada pela carencia de conhecimentos sobre diversos segmentos dos sistemas de producao, especialmente com relacao a estudos sobre nutricao mineral de plantas. Dessa forma, em amostras superficiais de ate 30 cm de profundidade de Latossolo Amarelo textura media do Municipio de Belem, Estado do Para, conduziu-se experimento, em casa de vegetacao, com plantas de acaizeiro, com o objetivo de identificar os nutrientes limitantes ao seu desenvolvimento, mediante a tecnica do elemento faltante. O delineamento experimental foi inteiramente ao acaso, com quatro repeticoes e 14 tratamentos: completo (calagem, macro e micronutrientes), NPK; omissao de N; de P; de K; de Ca; de Mg; de S; de B; de Cu; de Fe; de Mn; de Mo e de Zn. Os resultados obtidos neste trabalho permitiram concluir que os macronutrientes mais limitantes para o crescimento de acaizeiros, em Latossolo Amarelo textura media, foram o fosforo, o nitrogenio, o potassio e o magnesio e entre os micronutrientes, o manganes.

Nutrição mineral de seringueira IV. Toxicidade de Boro em Hevea brasiliensis

Com frequencia observa-se no Brasil nas areas de seringueira sintomas visuais de deficiencia de boro, quer na fase de formacao das mudas em crescimento em viveiro, quer no jardim clonal e mesmo nos primeiros anos de desenvolvimento das plantas definitivas. Foi tambem constatado que estas deficiencias estao associadas com adubacao de N, P, K, Mg. Este fato levou os autores a determinar a resposta a plantulas de seringueira a niveis crescentes de boro no substrato (0,5; 1,0; 1,5; 2,0 e 2,5 ppm de B). Plantulas do clone Tjir 1 foram cultivadas em vasos contendo como substrato silica moida, acrescida de solucao completa com os niveis de boro acima indicadas. Nove dias apos o ensaio dos tratamentos o efeito do boro se fez notar. As plantas cresceram com menor intensidade e apareceram sintomas nas folhas, lembrando a carencia de potassio. Houve queda acentuada de folhas. As concentracoes de boro eram muito altas nas folhas variando entre 316 e 1300 ppm. No caule e nas raizes as concentracoes eram menores de 21 a 85 ppm. Os autores concluem que a seringueira e muito sensivel a toxicidade de boro, devendo ser dada uma atencao especial com este micronutriente nas plantacoes.

Nutrição mineral de seringueira: IX. alumínio no substrato afetando o desenvolvimento, a sintomatologia de toxicidade e a concentração em seringueira (Hevea spp)

In Brazil mostly all rubber tree, under natural and cultivated conditions occurs on soil containing high levels of toxic aluminum. A study on the rubber tree behavior in relation to aluminum in necessary and urgent. In order to: - Study the effects of five levels of aluminum in the substract on the growth of young rubber trees; - Describe visual symptoms of the aluminum toxicity on the leaves; - Evaluate the tolerance of rubber plant to aluminum; Young rubber plants were cultivated in BOLLE-JONES (1957) nutrient solution, modified for iron supply. A separate solution of aluminum was prepared by dissolving a thin aluminum foil with HCl 1N. From these stock solution the following solutions were prepared: none, 5, 10, 15, 20 and 25ppm of aluminum. The plants remained for 24 hours in nutrient solutions and another 24 hours in the aluminum solutions. These procedure was carried out during 95 days. Both solutions - nutrient and aluminum -were replaced every week. After 95 days, the plants were harvested and divided into top whorl, 2nd and 3rd whorls, stem and roots. The material was dried and analysed for aluminum by routine methods in the laboratory. The authors concluded: - The growth of the rubber plants was affected when the concentration of aluminum was 15ppm or more in the solution. - Clear cut symptoms of the aluminum toxicity was noted in the roots. The root tip and lateral roots became thockened and turned brown. - The rubber plant grows well in presence of less thon 15ppm of aluminum.

Production of Caupi Beans and Chemical Attributes of a Latosol Under Soil Correction Levels

The cowpea [Vigna unguiculata (L.) Walp] represents an important source of income and employment in the northeastern region of Para, also being a valuable source of protein in the diet, especially for the rural population. However, the productivity is low, mainly due to the low fertility of the soils used in the region for the cultivation of this plant. In this context, the correction of the factors responsible for the soil limitations that lead to nutrient deficiency, by means of lime, is of great practical importance for obtaining greater yields of crops grown in acidic soils. The objective was to evaluate the effects of five doses of lime in the production of cowpea beans, BR3-Tracuateua and BR2-Braganca cultivars and chemical attributes of a dystrophic oxisoil, at Tracuateua city. The study was a randomized block designed experimental in a factorial (5 × 2) with four replications. The terms of the factorial refer to five doses of limestone and two cowpea cultivars. Liming increased pH and concentrations of phosphorus, calcium and magnesium, reducing the Al concentration and saturation. Lime dosages did not provide significant increases in grain production. The cultivar BR3-Tracuateua was more efficient in all liming levels, producing more than 30% of grain than the BR-2 Braganca.

Nutrição mineral de seringueira: XI. Quantidade de alumínio no substrato afetando a concentração e o acúmulo de nitrogênio, fósforo e potássio em seringueira (Hevea sp.)

Young rubber trees were cultivated in Bolle-Jones nutrient solutions modified for iron supply. A separate solution of aluminum was prepared by dissolving a thin aluminum foil with HCl 1N. From these stock solution the following solutions were prepared: 0, 5, 10, 15, 20 and 25ppm of aluminum. The plants remained for 24 hours in nutrient solution and for another 24 hours in the aluminum solutions. The procedure was carried out during 95 days. After 95 days the plants were harvested and divided into top whorls, remaining whorls, stem and roots. The material was analysed for N, P and K by routine methods. The authors concluded that the rubber plant is tolerant to concentration up to 15ppm of aluminum in the substract. Higher levels induce malnutrition of N, P and K in plants.