ABSTRACT: The objective of this study was to evaluate the optimum plot size to three sunflower hybrids in three spatial arrangements of plants. The uniformity test was installed in the experimental field of the Federal University of Recôncavo of Bahia, in Cruz das Almas, Brazil, in 2012. The plots were composed of six lines of 36 m, which were willing three spatial arrangements of plants: A1 (0,45 m x 0,49 m); A2 (0,70 m x 0,32 m) and A3 (0,90 m x 0,25 m), and each arrangement were distributed three sunflower hybrids: Hélio 250, Hélio 253 e Aguara 3. For the evaluation of the optimal plot size, at 110 days after sowing was harvested a sample of 180 basic units (plants) per plot, in which were evaluated the final plant height, the final diameter of the rod and the diameter of the chapter. Thirty-one plots sizes of three hybrids were simulated and for each variable assessed, wherein each plant was considered as a basic unit. The estimation of optimum plot size to the sunflower crop was calculated by the method of modified curvature maximum. The combined use of hybrid H253, installed in the arrangement 0.45 m x 0.49 m, promotes obtainment the greatest value of curvature maximum it was estimated the optimum plot size of six plants. | RESUMO: O objetivo deste estudo foi avaliar o tamanho ótimo de parcela de três híbridos de girassol em três arranjos espaciais de plantas. O teste de uniformidade foi instalado no campo experimental da Universidade Federal do Recôncavo da Bahia, em Cruz das Almas, Brasil, em 2012. As parcelas foram compostas por seis linhas de 36 m, sendo dispostos três arranjos espaciais de plantas, quais sejam: A1 (0,45 mx 0,49 m); A2 (0,70 mx 0,32 m); e A3 (0,90 mx 0,25 m). Foram distribuidos em cada arranjo três híbridos de girassol: Hélio 250; Hélio 253; e Aguara 3. Para a avaliação do tamanho ótimo de parcela , aos 110 dias após a semeadura, foi colhida uma amostra de 180 unidades básicas (plantas) por parcela, no qual foram avaliadas a altura final de planta, o diâmetro final da haste e o diâmetro do capítulo. Foram simulados 31 tamanhos de parcela dos três híbridos e para cada variável analisada em cada planta considerada como uma unidade básica. A estimativa do tamanho de parcela para a cultura de girassol foi calculada pelo método de máxima curvatura modificada. O uso combinado do híbrido H253, instalado no arranjo de 0,45 mx 0,49 m, promoveu a obtenção do maior valor da máxima curvatura, estimando-se o tamanho ótimo de parcela de seis plantas.

The objective was to compare models by Bayes factor (BF) to estimate the (co)variance compo- nents, genetic parameters and genetic values for the adjusted weights at 205 (W205), 365 (W365) and 550 (W550) days of age in Tabapuã animals reared on pasture in the Brazilian Northeast. Information about 26,838 cattle born in the period from 1975 to 2007 originally from the weight - development - control system of the Bra- zilian Association of Zebu Farmers ( Associação Brasileira de Criadores de Zebu , ABCZ) was used. The (co) variance components and genetic parameters were estimated by the Bayesian approach, in single - and two - trait analysis, using the GIBBS3F90 software. The full model provided the best fit to estimate the breeding value for W205 and W365 characteristics parameters. For trait W550, the model that provided the best fit was the one that did not include the effect of permanent environment. Genetic trends of direct effect were significant for the W205, W365 and W550 features, corresponding to increments of 2.67 kg, 7.35 kg and 8.32 kg, respectively, during the 32 years evaluated. Phenotypic trends were significant only for W205 and W365 characteristics cor- responding to increments of 26.82 kg and 22.42 kg, respectively. The genetic correlations between weight at 205, 365 and 550 days of age were of high magnitude (P205P365 = 0.90, = 0.90 and P205P550 P365P550 = 0.98); you can obtain genetic gains via correlated response to the weights at 365 and 550 days old when select- ing for W205.

The population density is one of the factors that affect the final yield of crops, being easily ma-nipulated by man. The objective was to evaluate the growth of castor bean plants cv BRS Energia in dense pop-ulations through primary data and non-destructive analysis of growth and identify which period greater vegeta-tive growth occurs. We adopted a randomized block design with five treatments and four replications, totaling 20 experimental units. Each experimental unit contained 4 m wide and 6 m in length, representing 24 m². Treatments involving five populations of plants 10.000; 16.666; 25.000; 50.000; 100.000 plants ha-1, with a spacing of 1 m between rows and 1; 0.6; 0.4; 0.2 and 0.1 m between plants, respectively. It was determined: stem diameter, plant height, leaf area, leaf area index and rates absolute and relative leaf growth, of stem diam-eter, of plant height and of fresh biomass epigeal. The castor bean BRS Energia has the highest rates of vegeta-tive increase between 15 and 45 days after emergence. Therefore, it is of great importance, in this period, pro-vide the plant water and nutrient conditions appropriate so that does not compromise on plant development.

The aim of this study was to evaluate the microbial activity and the contribution of light organic matter (LOM) in areas under natural regeneration of the Caatinga, checking the effect of seasonality and turn (daytime and nighttime) about the the release of CO2 from the soil. The experiment was conducted in the mu-nicipality of Santa Terezinha, Paraíba, where four areas were selected: (1) pasture (P), (2) Early Stage (E) of natural regeneration in the last five years, (3) Intermediate Stage (I) regenerating the last 15 years, and (4) Late Stage (L) of approximately 50 years. Microbial activity was determined in the field, monthly in two turns (daytime and nighttime). Respiratory activity in the soil was low in all areas and periods evaluated, with the lowest values for the areas of P and L. The CO2 values tended to be higher in the rainy season when compared to the dry season. The content of LOM was higher in P and E, in the dry season, and did not differ statistically between the areas during the rainy season. All attributes have tended to be influenced by temperature and soil moisture.

Moringa (Moringa oleifera Lam.) is an exotic species, from the Indian Northeast, the Moringaceae family and has significant economic importance, with many applications in industry and medi-cine. This species spreads mainly by seed, so obtaining information on the behavior of different temperature and substrate on germination becomes essential since there is no standardized methodology for installation of the germination test. Therefore, this study aimed at evaluating the influence of substrate and temperature on germination and vigor of Moringa oleifera Lam. seeds. The experiment was conducted at the Seed Analysis Laboratory of the Federal Rural University of the Semi-Arid (UFERSA). The statistical design was completely randomized in a 5x2 factorial scheme (temperature x substrate), totaling ten treatments with four replicates of 25 seeds. The substrates were tested roll paper and vermiculite. Then the seeds were incubated at room Bio-chemical Oxygen Demand (B.O.D.) at constant temperatures of 20, 25, 30 and 35 °C and 20-30 °C alternating with a photoperiod of 8 hours. We evaluated the percentage, the average time and the germination speed index and the shoot length and root and total dry weight of seedlings. The roll paper substrate at temperatures of 25 to 30 °C, as well as vermiculite of 30 °C temperature are the most suitable combinations to evaluate germination and vigor of seeds of Moringa oleifera Lam.

The aim of the present study was to determine the prevalence of Babesia bovis and Babesia bigemina in dairy cattle from São Luis Island in the state of Maranhão, Brazil. A total of 281 blood samples were collected. In total, 275 (97.9%) animals were B. bovis-reactive and B. bigemina reactive in the Enzyme-Linked Immunosorbent Assay (ELISA). The microscopy examination detected 22 (7.8%) animals that were positive for Babesia sp. and the Polymerase Chain Reaction (PCR) analysis showed that 91 animals (32.38%) and 23 animals (8.18%) were positive for B. bovis and B. bigemina, respectively, while 17 animals (6.04%) were co-infected. There is a high level of transmission of these protozoa in Maranhão, and the animals were naturally exposed. Therefore, it is possible to characterize the island as enzootic stability for babesiosis, indicat-ing a risk of financial losses when susceptible animals are introduced from areas of enzootic instability or free regions of B. bovis and B. bigemina.

Desmanthus is a genus of forage legumes with potential to improve pastures and livestock produc-tion on clay soils of dry tropical and subtropical regions such as the existing in Brazil and Australia. Despite this patterns of natural or enforced after-ripening of Desmanthus seeds have not been well established. Four year old seed banks of nine Desmanthus genotypes at James Cook University were accessed for their patterns of seed softe-ning in response to a range of temperatures. Persistent seed banks were found to exist under all of the studied ge-notypes. The largest seeds banks were found in the genotypes CPI 78373 and CPI 78382 and the smallest in the genotypes CPI’s 37143, 67643, and 83563. An increase in the percentage of softened seeds was correlated with higher temperatures, in two patterns of response: in some accessions seeds were not significantly affected by tempe-ratures below 80º C; and in others, seeds become soft when temperature rose to as little as 60 ºC. At 80 °C the heat started to depress germination. High seed production of Desmanthus associated with dependence of seeds on eleva-ted temperatures to softening can be a very important strategy for plants to survive in dry tropical regions.

The goal of this paper was to study the morphogenetic responses of jenipapo explants in differ-ent culture conditions in vitro to support multiplication and in vitro production of secondary metabolites proto-cols. After 90 days of cultivation, the jenipapo seedlings were segmented (nodal and leaf segments) and trans-ferred to MS medium supplemented with 30 g L-1 sucrose and different concentrations of 2.4 2.4-Dichlorophenoxyacetic acid -2.4-D (0; 4 and 8 mg L-1) combined with four concentrations of benzilamino-purine- BAP (0; 1; 2 and 3 mg L-1). After 120 days the percentage of explants with morphogenetic response, as is the formation of calluses and/or organogenesis was evaluated. The 2.4-D at concentrations of 4 and 8 mg L-1 induces an increase in morphogenetic response, especially in callus formation, of leaf and nodal segments. The BAP 1.77 mg L-1 induces increased callus formation in leaf segments and induces their higher shoot regenera-tion in leaf and nodal segments. The concentrations of 2.4- D and BAP studied do not induce the formation of somatic embryogenesis in leaf and nodal segments of jenipapo SIR access.

The objective of this study was to evaluate the optimum plot size to three sunflower hybrids in three spatial arrangements of plants. The uniformity test was installed in the experimental field of the Federal University of Recôncavo of Bahia, in Cruz das Almas, Brazil, in 2012. The plots were composed of six lines of 36 m, which were willing three spatial arrangements of plants: A1 (0,45 m x 0,49 m); A2 (0,70 m x 0,32 m) and A3 (0,90 m x 0,25 m), and each arrangement were distributed three sunflower hybrids: Hélio 250, Hélio 253 e Aguara 3. For the evaluation of the optimal plot size, at 110 days after sowing was harvested a sample of 180 basic units (plants) per plot, in which were evaluated the final plant height, the final diameter of the rod and the diameter of the chapter. Thirty - one plots sizes of three hybrids were simulated and for each variable assessed, wherein each plant was considered as a basic unit. The estimation of optimum plot size to the sun- flower crop was calculated by the method of modified curvature maximum. The combined use of hybrid H253, installed in the arrangement 0.45 m x 0.49 m, promotes obtainment the greatest value of curvature maximum it was estimated the optimum plot size of six plants.

In order to determine the water requirement and crop coefficient for the different phenological stages on corn plants ( Zea mays L.) and cowpea plants ( Vigna unguiculata (L.) Walp) in intercropping and sole cropping systems under the climatic conditions of the Brazilian semiarid. The experiment was conducted in the city of Petrolina, PE. Shoots total dry mass and photosynthetically active radiation intercepted for both crops were monitored. Furthermore, it was obtained the evapotranspiration (ETc) by the soil water balance method. With these data and reference evapotranspiration it was obtained crop coefficient (Kc), which were subsequent- ly used to adjust models as a function of accumulated degree days. With the results, it was found the water re- quirements from maize and cowpea intercropped system were greater than the sole system. Kc in the inter- cropped system was 0.90, 1.30, 1.20 and 0.72 for maize and 0.86, 1.30, 1.21 and 0.91 for cowpea, respectively, for the vegetative, flowering, grain filling and ripening stages. In the sole system, these values were, 0.86, 1.23, 0.97 and 0.52 for maize and 0.68, 1.02, 1.06 and 0.63 for cowpea in those phases mentioned. The variations of the Kc values for both systems and cultures have been associated to the increase of biomass and light intercep- tion. The Gaussian model adjusted properly described the relationship between Kc and accumulated degree days.