Rodrigo Gomes Pereira

Adubação nitrogenada para o milho cultivado em sistema plantio direto, no Estado de Alagoas

The objective of this work was to evaluate the effects of nitrogen doses upon production components of corn cultivated under a no-tillage system. Four nitrogen rates (0, 40, 80 and 120 kg ha-1) and five cultivars (AG-9010, TRACTOR, DOW-8550, DKB-395 and AL-34) were used. For all treatments, except for the control 20, 115, 60 and 4 kg ha-1 of N, P205, K2O and Zn were applied, respectively. The statistical design was the completely randomized block with four replications in a split plot scheme. The yield components studied were: plant population at harvest, ear length, number of grain rows per ear, ear number, and mass of 100 grains. The yield of the germoplasm varied from 1,900 kg ha-1 for the control to 5,662 kg ha-1 for the highest N dose (120 kg ha-1). For yield, it was observed that the hybrids DOW-8550 and AG-9010 were the most promising. It may be concluded that the economic return of the N fertilization can be reached with a 120 kg ha-1 dose. Both hybrids and cultivars used showed high efficiency in the use of the applied N, the hybrids being more responsive than the varieties.

Variance Analysis of genes in bacteria producing the enzyme chlorohydrolase atrazine used in the bioremediation of xenobiotics

Bioremediation is the process in which are employed organisms, plants or microorganisms for removal or reduction of pollutants into the environment, either on the ground or water. The biological process of bioremediation is ecologically more suitable and effective for treatment of contaminated environments contaminated with organic and recalcitrant molecules and toxic metals. Recalcitrant molecules which pollute the environment are generally called xenobiotic are the result of anthropic action, as they are synthetic chemical compounds produced industrially by humans and include plastics, solvents, lubricants, detergents, pesticides explosive, comprising thus a large number of molecules of different applications, potential toxicity, and remain in the environment. When these elements are in the natural ecosystem in large quantities, exhibit toxic effects or other undesirable effects by organisms [1,2]. Atrazine pertecente the class of s-triazines is considered a xenobiotic being widely used in agriculture as a herbicide and thus widely detected in groundwater as far surface [3]4. The key enzyme for the initial biodegradation of this compound is the atrazine chlorohydrolase (Atza), performs an action of hydrolytic removal of the ring of the compound [3]. Currently, through the use of bioinformatics tools can be studied in depth the composition and organization of microorganisms and their genetic variations. The NCBI database provides many information about the organisms, such as sequences of specific genes or entire genomes of organisms 5. This study aimed to evaluate the variations in the gene that codes for the enzyme atrazine chlorohydrolase in 10 bacterial species through the construction of a phylogenetic tree. Through observing the results could be verified that among analyzed bacteria only Rhodococcus corallinus emerges from a different ancestral in the phylogenetic tree and the remainder strains analyzed constitute a group rate descendant of a single common ancestral, with slight variation in the gene encoding the enzyme atrazine chlorohydrolase.

Production of mango tree fruit 'Tommy Atkins' fertilized with superphosphate in the city of Assú - RN.

A mangueira (Mangifera indica L.) e uma fruteira de grande importância economica no mundo. Com o objetivo de verificar o efeito da adubacao fosfatada sobre a producao de mangas ‘Tommy Atkins’, foi conduzido um experimento, na Fazenda Sao Francisco, no periodo de junho/2008 a marco/2009, no Vale do Acu - RN. Utilizou-se o delineamento em blocos ao acaso com 5 tratamentos de adubacao fosfatada (0; 50; 100; 150; 150 gramas de P 2 O 5 ) e quatro repeticoes, constituidas por seis plantas, na parcela experimental, considerando como parcela util as quatro plantas centrais. Como fonte de P, foi utilizado o superfosfato simples (18% de P 2 O 5 ). O adubo fosfatado foi aplicado em unica vez, apos a poda de frutificacao e antes da floracao. As plantas de mangueira possuiam 9 anos de idade. A colheita foi realizada 9 meses apos adubacao das plantas. Avaliou-se o numero de de frutos/planta, peso de frutos/planta e producao total/planta. Nao houve efeito significativo das doses de fosforo sobre nenhuma das variaveis avaliadas para esse ciclo de producao. Os valores medios para numero de frutos/planta, peso de frutos/planta e producao total/ha foram 255, 140g e 13t, respectivamente.