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Umuarama, Brazil

Cantuario F.S.,IF Goiano | Luz J.M.Q.,UFU ICIAG | Pereira A.I.A.,IF Goiano | Salomao L.C.,IF Goiano | Re-Boucas T.N.H.,UESB
Horticultura Brasileira | Year: 2014

The response of sweet pepper plants submitted to water stress is little known. The search for inducing resistance to water stress (such as silicon fertilization) can be an important step to reduce the negative effects of this abiotic stress. Thus, the aim of this study was to test the hypothesis that silicon fertilization through foliar applications can mitigate the incidence of anomalies caused by water stress on fruit quality of sweet pepper. The experiment was carried out in a greenhouse at the experimental horticulture area of the Instituto Federal Goiano, câmpus Urutaí, Goiás state, Brazil. The experimental design was randomized complete blocks, in a 3×4 factorial design, with split plots in space, and three levels of silicon (0.0, 4.3, 8.6 kg ha-1) in the form of potassium silicate (K2SiO3) and four soil water tensions of approximately -15, -25, -35 and -45 kPa, totaling 12 treatments with four replications. Water levels in the soil for the production of sweet pepper cultivar Magali-R, ranged from sufficient supply of water to the drought and also intermediate values. Twenty one foliar applications of potassium silicate were used weekly throughout the experiment. Increased soil water tension and the absence of potassium silicate were correlated with the incidence of blossom-end in fruits. The incidence of scald in sweet pepper fruits was not influenced by any of the two studied factors. A total of 129 fruits of sweet pepper presented blossom-end rot and 70 fruit presented scald, representing 2.14% and 1.16% of total harvested fruit.

Fracetto G.G.M.,University of Sao Paulo | Azevedo L.C.B.,UFU ICIAG | Fracetto F.J.C.,University of Sao Paulo | Andreote F.D.,University of Sao Paulo | And 2 more authors.
Scientia Agricola | Year: 2013

Considered as one of the most biodiverse biomes, the Amazon has a featured role in the discovery of new species of plants, animals and microorganisms, which may be important for the functionality of different ecosystems. However, studies on the impacts resulted from changes in the Amazon land use on microbial communities and their functions are still limited. In this context, the soil fungal diversity can act as an important indicator of environmental stress caused by land use of the Amazon. This study describes changes in soil fungal communities caused by different systems of land use (primary forest, secondary forest, agroforestry, agriculture and pasture). Communities were observed in each of the areas using denaturing gradient gel electrophoresis (DGGE) of 18S rRNA gene combined with the non-metric multidimensional scaling (NMDS). Unique bands indicated the dominance of particular fungal groups in each of the specific treatments, mainly in areas converted to pasture, which differed greatly from samples of other systems of land use (SLU). The analysis of partial sequence of the 18S rRNA gene of fungi in soils under primary forest, agriculture and pasture showed differences (p = 0.001), evidencing the fungal community response to such changes. Most abundant phyla were the Zygomycota in the soil under primary forest and agricultural land, and Basidiomycota in the soil under pasture. The results show that the Amazon soil is an ecosystem susceptible to environmental changes in regarding the fungi community inhabiting this niche.

Luz J.M.Q.,UFU ICIAG | Bittar C.A.,UFU ICIAG | Queiroz A.A.,UFU ICIAG | Carreon R.,Aminoagro
Horticultura Brasileira | Year: 2010

The tomato ranks second in economic importance among the vegetables in Brazil. To increase the productivity, technologies are currently used as the foliar application of the organic-mineral fertilizer and fertigation, which aims at stimulating and improving the root system development and, at the same time, is a balanced source of nutrients for plants. The objective of this work was to evaluate the agronomic efficiency of commercial liquid organic-mineral products applied to the leaf and through fertigation and its effects on fruit yield and quality of tomato hybrid Débora Pto. The experiment was carried out in Uberlândia, Minas Gerais State, Brazil, in the entirely randomized experimental design with three treatments and eight replications. The treatments were: Control; Treatment 1: drip irrigation of Aminoagro raiz 0.5 L ha -1 after transplanting and foliar application of Aminoagro folha top 0.2 L ha -1, Aminoagro fosfito 0.2 L ha -1, Aminoagro energy 0.5 L ha -1 and Aminoagro fruto 0.2 L ha -1 and Aminoagro mol 1 L ha -1, started at transplanting; Treatment 2: foliar fertilizer with Aminoagro raiz 0.5 L ha -1 after transplanting; Aminoagro folha top 1 L ha -1; Aminoagro energy 2 L ha -1 with the Aminoagro folha top; Aminoagro mol 2 L ha -1 and 3 L ha -1, Aminoagro fosfito 1 L ha -1 and Aminoagro fruto 1 L ha -1. The evaluated variables were: the production of fruits according to their classification by size into the groups 2A, 1A and discarded fruits. The results showed that from the third week on, the treatments 1 and 2 presented higher production of tomato extra type 2A. The same occurred for the total commercial production. Total production was significantly higher in treatments 1 and 2, which received organic-mineral fertilizers and the income generated by those treatments was superior to the control treatment.

Sodre A.C.B.,UFU ICIAG | Haber L.L.,Embrapa Hortalicas | Luz J.M.Q.,UFU ICIAG | Marques M.O.M.,IAC | Rodrigues C.R.,Federal Rural University of Pernambuco
Horticultura Brasileira | Year: 2013

Lemon balm (Melissa officinalis) is a medicinal plant commonly used as a sedative and ingested as a tea. Studies on agricultural practices are required to optimize its yield. To optimize its production, this study evaluated the effect of different doses of organic fertilizer (cow manure) in comparison to mineral fertilizer on biomass production and essential oil yield. The experiment was carried out at the Federal University of Uberlândia, Minas Gerais state, Brazil, and at the Agronomic Institute of Campinas, São Paulo state, Brazil. The experimental design was randomized blocks with six treatments (0, 1, 2, 4, 8 kg m-2 of manure and 30 g m-2 of NPK 4-14-8), and four replications. Hydro-distillation was done with a modified Clevenger distiller for essential oil extraction. Cattle manure influenced plant height, total fresh and dry mass of leaves, per plant and per hectare. The two fertilization forms were better than the non-fertilized control for all variables, except for leaf length and width and oil content in the leaf fresh and dry matter. It can be concluded that lemon balm is responsive to organic fertilization with manure and mineral fertilization for biomass production.

Luz J.M.Q.,UFU ICIAG | Queiroz A.A.,Federal University of Uberlandia | Oliveira R.C.,UFU ICIAG
Horticultura Brasileira | Year: 2014

The high response of potato to the addition of nutrients to the soil, requires special attention to aspects related to fertility, especially nitrogen (N), because it is the nutrient that causes the greatest impact on productivity. In order to identify the critical content of N in potato in response to the nitrogen doses, we installed an experiment in Perdizes, Minas Gerais state, Brazil, from July to November 2010 using the cultivar Asterix. The experimental design was randomized blocks with five N levels (0, 70, 140, 210 and 280 kg ha-1) and four replications. The N doses were split, applying 20% at planting date and 80% on coverage, along with the operation of ridging thirty days after planting. The rest of fertilization consisted of 400 kg ha-1 P2O5 and 300 kg ha-1 K2O, combined with 30 kg ha-1 of a source of micronutrients. About fifty days after planting date we obtained one sample of leaves of the plots, which were subjected to analysis of N content in leaf tissue. At the end of the crop cycle harvested tubers were weighed and calculated the productivity of the floor area of the parcels being converted into kg ha-1. The critical level was determined as a function of the applied doses, the estimated yield and foliar N. The estimated N that provides the highest yield of potato tubers is 173 kg ha-1, the obtained yield corresponding to 21.8 t ha-1 of tubers. Considering the dose to obtain 90% of the yield (155.7 kg ha-1), the critical leaf N content is estimated to be 67.6 g kg-1.

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