Time filter

Source Type

Cruz das Almas, Brazil

Nunes J.C.,UFPB. Cidade Universitaria | Cavalcante L.F.,Federal University of Paraiba | de Lima Neto A.J.,Sao Paulo State University | Rebequi A.M.,PPGCS CCA UFPB | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental

An experiment was carried out in greenhouse during the period January to April 2010, at Center of Agricultural Sciences of the Federal University of Paraiba, in Areia, Paraiba State, Brazil, in order to evaluate the effects of saline water and bovine biofertilizer on the seedling growth of Indian neem. The substrate was material of a non-saline soil collected in depth of 0-20 cm. The treatments were arranged in a completely randomized design using a 5 × 2 factorial, referring to salinity levels of irrigation water of 0.5, 1.0, 2.0, 3.0 and 4.0 dS m-1, with and without bovine biofertilizer applied to the soil only once after dilution with water (1:1), a day before sowing, in volume corresponding to 10% of the substrate. At 86 days after emergence of seedlings the plant growth in height and principal root length, diameter of stem and root, leaf number and dry mass of roots and shoots of plants were evaluated. The salinity of irrigation water increased the salinity levels in the substrate inhibiting the growth in height, stem diameter, leaf emission by plants, diameter and length of principal root and the dry matter production of roots and aerial parts (leaves + stem) of neem, but with less pronounced decrease in plants under the treatments with bovine biofertilizer. Source

De Lima R.L.S.,Brazilian National Council for Scientific and Technological Development | Severino L.S.,Pesquisador da Embrapa Algodao | Pereira W.E.,Federal University of Paraiba | De Lucena A.M.A.,Brazilian National Council for Scientific and Technological Development | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental

Jatropha curcas is traditionally propagated by seed. However, in several situations the vegetative propagation is an important alternative and its technology needs to be developed. The objective of this study was to evaluate how the length and the portion of the branch from where the cuttings are extracted, influence the rooting and growth capacity of Jatropha cuttings. The treatments were arranged in a 3 x 4 factorial design, with three cutting positions (apical, middle and basal) and four cutting lengths (10, 15, 20, and 25 cm). A completely randomized design with four replications and ten cuttings per plot was adopted. At 70 days after planting, the cuttings were evaluated for the number of sprouts and branches, branch length, number of leaves, leaf area, number of roots, and dry mass of shoots and roots. The position from where the cuttings are extracted (apical, middle or basal) did not influence its capacity for rooting and the growth of the seedlings. The cutting length influences the initial growth, and the best growth was obtained in cuttings of around 22 cm. Source

de Porto Filho F.Q.,DCA UFERSA | de Medeiros J.F.,DCA UFERSA | Gheyi H.R.,NEAS UFRB | da Dias N.S.,DCA UFERSA | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental

This work aimed to study the effects of irrigation with saline waters in an area cultivated with melon on soil salinity and pH. The experiment was conducted in the Santa Julia Farm, Mossoró city, Rio Grande do Norte State, Brazil, during the years 2001 to 2002. Water with different salinity levels (0.6; 1.9; 3.2 and 4.5 dS m -1) was used throughout the cycle and in incremental way in three periods of melon development, forming 15 treatments, arranged in randomized blocks with four replications. The salinity was measured at 0, 30, 50 and 70 days after sowing in soil samples collected in layers of 0-15, 15-30 and 30-45 cm. There was greater accumulation of salts in the surface layer (up to 15 cm) in all salinity levels and the use of more saline water produced higher average salinity in the profile. The average values of pH were within the range of optimal absorption of nutrients required by melon. Source

Lima R.L.S.,Brazilian National Council for Scientific and Technological Development | Severino L.S.,Embrapa Algodao | Sofiatti V.,Embrapa Algodao | Gheyi H.R.,NEAS UFRB | Arriel N.H.C.,Embrapa Algodao
Revista Brasileira de Engenharia Agricola e Ambiental

The urban waste compost is an organic material rich in some nutrients, commonly used as an ingredient in substrates for seedling production. The effects of addition of waste compost on the chemical properties of substrate were evaluated in a greenhouse experiment conducted in Campina Grande, PB under a completely randomized design with four replications and 10 polytubes per plot. The treatments consisted of 4 doses of compost (0, 10, 20 and 40% - v/v) added to samples of sandy Entisol. Polytubes of 288 cm3 were used as containers for incubation. The mixture of soil and organic waste compost was incubated for 40 days at moisture content equivalent to 60% of field capacity. After the incubation the substrates were analyzed for pH in CaCl2 and content of Ca2+, Mg2+, Na+, K+, sum of cations (mmolc dm-3), cation exchange capacity (mmolc dm-3), base saturation (%) and organic matter (g kg-1)). The fertility of substrate increased with the addition of urban waste compost. Source

Santos Junior J.A.,INSA | Gheyi H.R.,NEAS UFRB | Dias N.S.,UFERSA | Medeiros S.S.,INSA | Filho D.H.G.,Federal University of Campina Grande
Revista Brasileira de Engenharia Agricola e Ambiental

Exploiting the potential of water and nutrients of wastewater is a viable alternative to increase the supply of water, especially in semi-arid regions. In this context, the aim of this study was to evaluate the growth of sunflower (Helianthus annuus L.), cv. Embrapa 122-V2000, for ornamental purposes, grown in semi-hydroponic system using different substrates and wastewater instead of nutrient solution. Te experiment was conducted in a completely randomized design and analysed in a 4x3 factorial scheme, with three replications, totaling 36 experimental units. Four time intervals of renovation/replacement of wastewater (daily, every two, three and four days) and three substrates (coconut fiber, sand and sugar cane bagasse) for cultivation were tested. It was found that the renewal time negatively affected the performance of length and diameter of the stem, leaf number and leaf area, but these growth parameters of flowers remained within the commercial standards for all times tested. Source

Discover hidden collaborations