Manoel Alexandre Diniz Neto

Mudas de oiticica irrigadas com águas salinas no solo com biofertilizante bovino e potássio

An experiment was carried out during the period of March to July of 2012 in the Agrarian Science Center of Federal University of Paraiba, Areia, Paraiba State, Brazil, in order to evaluate the initial growth of Licania rigida plants by height, stem diameter, leaf area, total chlorophyll content and biomass of the roots and of the aerial parts of the plants as function of water salinity and bovine biofertilizer and with potassium in the soil. Treatments were arranged in entirely randomized design, with six replicates, in factorial scheme 5 x 2 x 2, corresponding to waters with electrical conductivity of 0.5; 1.5; 3.0; 4.5 and 6.0 dS m-1 in soil without and with 300 mL of bovine biofertilizer applied one time on soil surface, and without and with 1.4 g of potassium chloride. The increment of salinity in irrigation water inhibited the growth and the quality of the seedlings, but with more loss in plants of the treatments without bovine biofertilizer and without potassium chloride. The plants cultivated in soil with potassium showed better growth in relation these of the treatments without the mineral fertilizer.

Componentes de produção de mamona em função de níveis de adubação nitrogenada e desfolha

Objetivou-se com esse trabalho, avaliar os componentes de crescimento e producao da mamoneira submetida a adubacao nitrogenada combinada com desfolha artificial da planta. O experimento foi conduzido na Estacao Experimental da Empresa Estadual Agropecuaria da Paraiba (Emepa-PB) localizada no municipio de Alagoinha-PB, entre os meses de abril e outubro de 2009. Foram utilizados cinco niveis de N-fertilizante (00-30-60-90-120 kg ha-1) combinados com quatro niveis de desfolha artificial (00-20-40-60%), distribuidos no delineamento de blocos ao acaso, com quatro repeticoes em arranjo fatorial 5 x 4. Foram avaliadas altura de planta, diâmetro caulinar, numero de nos, massa de 100 graos e produtividade de graos. As variaveis de crescimento aumentam com os niveis de N-fertilizante nos niveis de desfolha de ate 20%. A partir desse nivel, ha tendencia de maior crescimento vegetativo com a aplicacao de menores doses de nitrogenio. A massa de 100 graos e a produtividade de graos aumentam com doses menores que 120 kg ha-1 de N-fertilizante em niveis de desfolha de ate 40%, mostrando que ha correlacao positiva entre essas variaveis de producao da mamoneira. A desfolha artificial quando combinada com adubacao nitrogenada provoca alteracoes nos componentes de crescimento e de producao da mamoneira, sendo importante avaliar ate que ponto e economicamente viavel a aplicacao do N-fertilizante e a possibilidade do uso de fontes alternativas desse nutriente.

Disponibilidade hídrica de dois solos e diferentes idades de corte no comportamento agronômico da Jureminha

The study was developed to evaluate the effects of two soil-types under different levels of water availability and cropping ages on the components of vegetative growth and chemical composition of jureminha plants (Desmanthusvirgatus L. Willd.). The treatments were distributed in a 2 x 4 factorial in a completely randomized block design with twelve replications of the factors: two soil types, one being from the humid region of the town of Alagoinha, and other from the semi-arid region of the town of Sao Joao do Cariri, both in the State of Paraiba; four levels of water availability (40, 60, 80 and 100% of the available water) and four cropping ages (60,; 90; 120 and 150 days after the emergence of seedlings), the study being carried out in a greenhouse at CCA / UFPB,in Areia, Paraiba. An increase in the water available in the soil stimulates plant growth but inhibits gross protein production in jureminha. Plants grew more, and produced less protein in the soil from Sao Joao do Cariri in relation to that from Alagoinha.