ABSTRACT The Cerrado occupies 25% of the Brazilian territory and is the second largest biome in South America, second only to the Amazon Rainforest. Hence, studies on the native species of the Cerrado are important for implementing conservation strategies. In this context, knowledge of the requirements and conditions for germination of seeds of these native species is essential. The Cerrado watermelon (Melothria campestris (Naudin) H. Schaef. & S.S. Renner) is a plant that is not cultivated, but has been used in revegetation projects in the countryside of the Cerrado because its fruits are fed upon by fauna in times of food shortage. The purpose of this study was to determine the most appropriate methodology for the germination of the Cerrado watermelon, by identifying the best-suited substrate, the optimal temperature, and the corresponding time taken for germination. The treatments consisted of four substrates: in a paper roll, on paper, in sand, and on sand; and four temperatures: 20, 25, and 30 °C (maintained constant), and a fourth temperature treatment that alternated 20-30 °C. The effect of the substrates and temperatures on seed performance was evaluated using the germination test, speed index, and average time for germination. The experimental design was fully randomized, with treatments distributed in a 4 × 4 (substrates × temperatures) factorial scheme, with four replications. Our results show that the temperature of 20 °C had a negative influence on germination in all substrates. Further, we found that the germination of the Cerrado watermelon seeds was best in a paper roll or on sand substrate, maintained at a constant temperature of 30 °C, or when temperature was alternated 20-30 °C, and the time required for germination stabilization was 30 days. | RESUMO O Cerrado ocupa 25% do território brasileiro e é o segundo maior bioma da América do Sul, perdendo somente para a Floresta Amazônica, sendo assim, estudos com espécies nativas são de fundamental importância para implementação de estratégias de conservação, no qual o conhecimento do comportamento da germinação das sementes é fundamental neste contexto. Melancia do Cerrado (Melothria campestris (Naudin) H. Schaef. & S.S. Renner) é uma frutífera não cultivada que tem sido utilizada em projetos de revegetação de ambientes campestres do Cerrado, pois seus frutos alimentam a fauna em épocas de escassez de alimentos. Objetivou-se determinar a metodologia quanto ao substrato, temperatura e tempo de contagem para o teste de germinação em melancia do Cerrado. Os tratamentos constaram de quatro substratos: rolo de papel, sobre papel, entre areia e sobre areia e quatro temperaturas: 20, 25 e 30 °C constantes e 20-30 °C alternada. O efeito dos substratos e temperaturas sobre o desempenho das sementes foi avaliado pelo teste de germinação, índice de velocidade e tempo médio de germinação. O delineamento experimental foi inteiramente ao acaso, com os tratamentos distribuídos em esquema fatorial 4 × 4 (substratos × temperaturas), com quatro repetições. A temperatura de 20 °C influenciou negativamente em todos os substratos. O teste de germinação em sementes de melancia do Cerrado pode ser realizado em rolo de papel ou sobre areia, à temperatura constante de 30 °C ou alternada de 20-30 °C, com contagem final no 30° dia.

ABSTRACT Due to the quantitative and qualitative limitation of water resources, saline water irrigation and nitrogen (N) fertilisation can contribute positively to the expansion of sunflower cultivation in the semiarid region of Northeast Brazil. Thus, this study aimed to evaluate production components and yield of sunflower, cv. "Embrapa 122-V2000‟, irrigated with waters of different salinity levels (electrical conductivity - ECw) and fertilised with varying amounts of N in a field experiment in a eutrophic Quartzarenic Neosol from November 2012 to February 2013. The experiment was performed in a completely randomised block design in split plots, in a 5 x 4 factorial scheme, which corresponded to five ECw levels (0.15, 1.5, 2.5, 3.5 and 4.5 dS m-1) and four N levels (60, 80, 100 and 120 kg ha-1), with three replicates and 30 plants per plot. The interaction between water salinity levels and N did not have significant effects on the studied variables; irrigation water salinity had isolated negative effects on the total number of achenes, number of viable achenes, productivity and oil yield of achenes. The increase in N levels stimulated the total number and the number of viable achenes, the mass of 1,000 achenes, capitulum diameter and productivity of achenes of sunflower, cv. "Embrapa 122-V2000‟, but had no effect on the oil content of achenes. N levels of up to 100 kg ha-1 promoted adequate oil content in the achenes of sunflower, cv "Embrapa 122-V2000‟. | RESUMO Diante da diminuição quantitativa e qualitativa de recursos hídricos, a irrigação com água salina e a adubação nitrogenada podem contribuir de forma positiva para a expansão do cultivo de girassol na região semiárida do Nordeste brasileiro. Deste modo objetivou-se com este trabalho avaliar os componentes de produção e o rendimento do girassol, cv. Embrapa 122-V2000, irrigado com águas de diferentes salinidades (condutividade elétrica - CEa) e níveis de nitrogênio no solo, em experimento de campo conduzido em um Neossolo Quartezarênico eutrófico no período de novembro de 2012 a fevereiro de 2013. O delineamento foi em blocos casualizados analisados em parcelas subdivididas, no arranjo fatorial 5 x 4, relativo a cinco níveis de CEa: 0,15; 1,5; 2,5; 3,5 e 4,5 dS m-1 e quatro níveis de nitrogênio de 60, 80, 100 e 120 kg ha-1, com três repetições e 30 plantas por parcela. A interação entre os níveis de salinidade da água de irrigação e de nitrogênio não exerceu efeitos significativos sobre as variáveis estudadas; os efeitos isolados da salinidade das águas de irrigação inibiram o número total de aquênios, o número de aquênios viáveis, a produtividade e o rendimento em óleo dos aquênios. O aumento dos níveis de nitrogênio, exceto sobre o teor de óleo dos aquênios, estimulou o número de aquênios total e viáveis, a massa de mil aquênios, o diâmetro do capítulo e a produtividade de aquênios do girassol cv. Embrapa 122-V2000. O nível de N de até 100 kg ha-1 proporcionou teor adequado de óleo nos aquênios de girassol cv. Embrapa 122-V2000.

RESUMO A palma tem grande importância para a pecuária da região semiárida do Brasil. Essa planta vem apresentando elevada produtividade de forragem, influenciada por vários fatores de manejo. Objetivou-se avaliar o efeito de doses de adubação orgânica (20, 40 e 80 t/ha de esterco bovino/ha/dois anos) e densidades de plantio (20, 40, 80 e 160 mil plantas/ha) sobre a produtividade da palma forrageira Clone IPA-20 (Opuntia ficus indica Mill). O experimento foi conduzido na Estação Experimental de Caruaru, pertencente ao Instituto Agronômico de Pernambuco - IPA. O delineamento experimental foi em blocos casualizados, com arranjo de parcelas subdivididas. Verificou-se maior produtividade de parte aérea com o aumento da densidade populacional e aplicação de 80 t de esterco/ha/dois anos, com valores de 61; 90; 117 e 139 t MS/ha/dois anos, nas densidades de 20, 40, 80 e 160.000 plantas/ha. A produtividade do cladódio-planta e peso seco da raiz foram influenciados pela densidade de plantio, apresentando respostas exponenciais, tendendo a apresentar maior peso do cladódio planta e raízes por área com a elevação da densidade de plantio. A eficiência da adubação orgânica diminuiu com a elevação das doses de esterco. Recomenda-se para plantios com 160.000 plantas/ha aplicação de, no mínimo, 40 t de esterco bovino/ha/dois anos para incremento na produtividade da palma. | ABSTRACT Cactus is crucial for the livestock of semi-arid regions in Brazil. This plant has shown the high productivity of forage, which is influenced by several management factors. This study aimed to evaluate the effect of organic fertilization doses (20, 40 and 80 t/ ha of bovine manure/ha/two years) and planting densities (20, 40, 80 and 160 thousand plants/ha) on the productivity of cactus pear Clone IPA-20 (Opuntia ficus-indica Mill). At the Experimental Station of Caruaru at the Agronomic Institute of Pernambuco, IPA has conducted the experiment. The experimental design was randomized blocks, with split plot arrangements. Higher shoot productivity was observed with increased population density and the application of manure at 80 t ha-1 two years-1 with values of 61, 90, 117 and 139 t DM ha-1 two years-1 at densities of 20, 40, 80 and 160,000 plants ha-1. The planting density influenced the productivity of cladode-plant and root dry weight, showing exponential responses, with higher cladode-plant and roots weight by area observed with increased plant density. The efficiency of organic fertilization decreased with the increase in manure doses. For increase cactus productivity, 40 t of bovine manure ha-1 two years-1 for plantations with 160,000 plants/ha is recommended.

ABSTRACT The Rafael Fernandes experimental farm is located in the Alagoinha district, northwest of Mossoró, State of Rio Grande do Norte, Brazil, over two pedogenic formations of different edaphic characteristics, thus needing a more detailed description of its soil types, since this area hosts several experimental fields for researches on agriculture. The objective of this work was to characterize the morphological, physical, chemical and mineralogical features of the most representative soils of this farm, in order to understand its pedogenesis and define its classifications. The whole area was surveyed in order to assess its more representative pedogenic formations. Three soil profiles were classified and described, from which samples were collected in all horizons for physical, chemical and mineralogical analysis. The parent materials and the relief were the determining factors for pedogenic processes of desilication, podzolization and laterization, generating the three main soil types of the area, which were classified up to the 4th categorical level and described as: Typic Rhodustults (P1), Rhodic Haplustox (P2) and Typic Plinthustalfs (P3). | RESUMO A fazenda experimental Rafael Fernandes está localizada no distrito de Alagoinha e inserida entre duas pedoformas da região noroeste do município de Mossoró-RN, apresentando características edáficas distintas, o que gera a necessidade de descrições mais detalhadas acerca das classes de solos existentes na área, uma vez que a mesma dispõe de diversos campos experimentais com pesquisas na área de ciências agrárias. Assim, a realização do presente trabalho teve como objetivo a caracterização morfológica, física, química e mineralógica dos solos mais representativos da fazenda a fim de compreender a pedogênese e definir sua classificação. Foram realizadas viagens de reconhecimento de toda a área para a decisão das pedoformas mais representativas e assim definidos três perfis de solo, os quais foram descritos e coletadas as amostras em todos os horizontes para a realização das análises físicas, químicas e mineralógicas. Os resultados permitiram concluir que o material de origem e o relevo foram os fatores determinantes para a ocorrência dos processos pedogenéticos de latolização, podzolização e plintitização, gerando a identificação de três classes de solo principais na Fazenda Experimental que, classificados em 4° nível categórico, definiram-se como: Argissolo Vermelho Distrófico Típico (P1), Latossolo Vermelho Distrófico Argissólico (P2) e Plintossolo Argiluvico Eutrófico Típico (P3).

The aim of the study was to evaluate the morphological and productive characteristics of five genotypes of Desmanthus spp. submitted to two cutting intensities (20 and 40 cm), in the semi-arid region of Pernambuco. Of the genotypes studied, three were derived from ecotypes collected in municipalities of Pernambuco (7G, 31D and 50J) and two were from the state of Sergipe, coming from Australia (10AU and 13AU). Four cuttings were made with a frequency of 60 days. The treatments were randomized in blocks, with split plots and three replications. The variables studied were plant height, stem diameter, canopy diameter, the number of leaves per branch, LAI, leaf yield, stem yield, pod yield and forage yield, and leaf stem-1 ratio and pod stem-1 ratio. Genotypes 7G and 31D had higher forage yield and a larger number of leaves per branch. Forage yield was higher in the intensity of 20 cm. The cuttings reduced the total yield, stem yield, pods yield and forage yield, of the different genotypes studied. For leaf stem-1 ratio, the genotype 13AU was higher than genotypes 7G and 50J in the cutting intensity of 40 cm. Genotype 10AU had the highest pod stem-1 ratios in the three cuttings. The differences shown between genotypes of Desmanthus spp., especially 7G and 31D, in the intensity of 20 cm, indicate the possibility of selecting promising materials for cultivation in the semi-arid region of Pernambuco, with desirable morphological and productive characteristics to the forage plants.

An experiment was conducted during the years 2009 and 2010 to evaluate the effects of Urochloa forage straw and nitrogen fertilization on soil properties, nutritional foliar content, index of foliar chlorophyll (IFC) values, production components, and grains yields of winter bean ( Phaseolus vulgaris ‘Pérola’) in the Cerrado lowlands region of Brazil. The treatments consisted of planting bean crops under straw of Urochloa brizantha ‘Xaraés’ and Urochloa ruziziensis, fertilized with urea - sourced N (0, 50, 100, 150, and 200 kg N ha - 1 ). The experimental design was randomized blocks with four replications, and a factorial scheme of 2 × 5. The greater yield of U. brizantha dry matter in the two years of evaluation increased bean leaf nutrient levels. The nutritional increase with increasing N application rates showed that the straw produced by the forages had a positive effect on bean nutrition. The grain yield was satisfactory but was not affected by the forage species nor by changes in the N application rates. The Urochloa straw increased the soil organic matter (SOM), Ca, and Mg content in both evaluated years, affected the decomposition and mineralization of organic residues, and ensured the proper development of the bean plants.

The ramularia leaf spot (RLS) disease causes cotton yield losses. Choosing a less susceptible cultivar and a sowing time that are less favorable to the pathogen contribute to the management of this disease. The objective of this work was to evaluate the severity of ramularia leaf spot on cotton cultivars sowed in two different times. The experiment was conducted in a triple factorial design (4x3x2), consisted of four cultivars, the three thirds of the plant and two sowing times, with four replications. Each plot was divided in two twin plots, one with fungicide application (with disease control) and the other without fungicide application (without disease control). The severity assessments were performed every seven days, considering each third of the plant with a diagrammatic scale. Yield was evaluated in each plot. There was a significant interaction between sowing times and the thirds of the plant in the plots without disease control for RLS severity, with the highest values of area under the disease progress curve (AUDPC) in the first sowing time (ST1) and in the lower third of the plant. The FMT705 cultivar had the highest and FM951LL the lowest value of AUDPC. The AUDPC of these cultivars were no statistically different in the second sowing time (ST2), but they had higher AUDPC values in the lower third. Highest yields were found with ST1 in plots with disease control, with no differences between the cultivars, however, lower yields were found in plots without disease control.

The aim of this study was to isolate sporogenic bacteria from the honey of stingless bees Melipona sp., in dry forest, and to evaluate their antagonistic potential for medicinal employment purposes and animal production. The honey samples were collected in Serra Talhada - PE, where honey was taken from four different hives (in triplicate), totaling 12 samples. The samples were diluted and subjected to 80 ºC for 20 minutes to eliminate vegetative cells. The dilutions were plated onto nutrient agar and incubated at 30 ºC for 72 hours. Then the colony forming units (CFU) were quantified. The samples were also plated onto malt agar and Sabouraud agar, and incubated at 30 ºC for 14 days for the growth of yeast and molds. Total and fecal coliforms were quantified by the most probable number method (MPN). Seven isolates (I) of sporogenic bacteria ( Bacillus ) were obtained, however only four showed probiotic potential. Isolate I - 5 showed the greatest probiotic potential and inhibited the growth of Escherichia coli , Klebsiella sp., Pseudomonas aeruginosa, Salmonella sp., and Staphylococcus aureus . The growth of the Sarcina sp. was not inhibited by any isolate. No yeast, molds or coliforms were found. The Melipona sp. honey is a source of spore - forming bacteria and is antagonistic to microorganisms that contaminate honey. It has good microbiological quality.

Cactus is crucial for the livestock of semi - arid regions in Brazil. This plant has shown the high productivity of forage, which is influenced by several management factors. This study aimed to evaluate the effect of organic fertilization doses (20, 40 and 80 t/ ha of bovine manure/ha/two years) and planting densities (20, 40, 80 and 160 thousand plants/ha) on the productivity of cactus pear Clone IPA - 20 ( Opuntia ficus - indica Mill). At the Experimental Station of Caruaru at the Agronomic Institute of Pernambuco, IPA has conducted the experiment. The experimental design was randomized blocks, with split plot arrangements. Higher shoot productivity was observed with increased population density and the application of manure at 80 t ha - 1two years - 1 with values of 61, 90, 117 and 139 t DM ha - 1 two years - 1 at densities of 20, 40, 80 and 160,000 plants ha - 1. The planting density influenced the productivity of cladode - plant and root dry weight, showing exponential responses, with higher cladode - plant and roots weight by area observed with increased plant density. The efficiency of organic fertilization decreased with the increase in manure doses. For increase cactus productivity, 40 t of bovine manure ha - 1 two years - 1 for plantations with 160,000 plants/ha is recommended.

Soil is an important water compartment into a watershed scale, mainly due to its role in providing water to plants and to the influence of antecedent moisture on the runoff initiation. The aim of this research is to assess the permanence of water effectiveness in the soil under preserved-vegetation constraints in the Caatinga biome, in the semiarid northeastern Brazil. For this purpose, hourly soil moisture measurements were collected with TDR and analyzed between 2003 and 2010 for three soil-vegetation associations in the Aiuaba Experimental Basin. The results showed that in nine months per year soil moisture was below wilting point for two associations, whose soils are Chromic Luvisol and Haplic Lixisol (Abruptic). In the third association, where the shallow soil Lithic Leptosol prevails, water was found non-effective four months per year. A possible reason for the high water permanence in the shallowest soil is the percolation process, generating sub-surface flow, which barely occurs in the deeper soils. In situ observations indicates that the long period of soil moisture below the wilting point was not enough to avoid the blooming season of the Caatinga vegetation during the rainy periods. Indeed, after the beginning of each rainy season, there is a growth of dense green vegetation, regardless of the long period under water shortage.