The P critical levels in plants depend from soil characteristics which reflect phosphate buffer power. In Pernambuco, soils mineralogical characteristics change at different regions where corn is cultivated. To evaluate P critical levels in corn plants in soil cultivated in different soils and contact periods of this element in the soil, aiming to study the relationships between these critical levels and P adsorption, it was realized an experiment using subsuperficial samples of a Vertissolo Ebânico órtico (VEo) (Mollisol), clay textured with predominance of 2:1 clay mineral and a Nitossolo Vermelho distroférrico (NVdf) (Nitosol), high clay content, predominantly hematitic, colleted at the semi - arid and humid regions of Pernambuco State, Brazil, respectively. The P doses were defined in function of the levels 0; 0.2; 0.4; 0.8 and 1.0 from the P Maximum Capacity of Adsorption (CMAP) of each soil and were incubated by 90; 60; 30; 15; and 0.5 days. The experiment was real- ized into a greenhouse in a factorial scheme (5x5x2), five P levels, five incubation periods and two soils, in randomized blocks delineation with three replicates each. Corn plants were more efficient to utilize P in NVdf, the soil with higher CMAP. The corn shoot critical levels decreased in accordance to the period of incubation in VEo, the soil with lower CMAP.

This study aimed to evaluate the potential for milk production (MP), lactation length (LL) and calv- ing interval (CI), analyze the environmental component affecting these traits, and to estimate the heritability and repeatability for milk production in crossbreds of Murrah buffalo cows in the state of Alagoas, Brazil. Data was composed of 487 observations of MP from 136 lactations recorded between the years of 2000 and 2010. In the analysis of variance for PL, the fixed effects were season (1- October to March, 2 -April to September) and year of the beginning of lactation, calving order and the LL (covariate). For the analysis of LL only the fixed effect of year of the beginning of lactation was included, and finally for the CI analysis, year of the beginning of lactation and calving order. The estimates of covariance were obtained using unicharacteristic analysis by Bayesian inference method, applyingan animal model, through Gibbs sampling. The additive genetic, perma- nent environment and residual effects were included as random effects in the model. The averages (sd) of MP, LL and CI were 2,218.03 kg (408.18), 282.59 days (39.48) e 422.49 days (91.05), respectively. All the effects included in the models were important (P<0.01). The estimates of heritability and repeatability for PL were 0.29 and 0.69, respectively. The results suggest that there is a moderate genetic variability among individuals for PL, indicating the possibility to obtain gain using selection.

In semiarid regions the irrigation is essential for obtaining high yields and fruit quality of pine- apple. The objective of this work was to evaluate the vegetative characteristics, fruit and slips production and fruit quality of pineapple, under different drip irrigation depth. The experiment was conducted in a randomized block design with five treatments replacement of class A evaporation pan (PAN), with 4 replications. The vege- tative growth, flowering, production and fruit quality and slips production were evaluated. The plants of pine- apple that have received regarding the irrigation at 30, 50, 70, 100 and 150% of PAN do not differ for the char- acteristics of productivity, fruit weight with and without crown diameter and fruit length, skin color, total solu- ble solids (TSS), total titratable acidity (TTA), TSS / TTA and pH of the pulp. The pineapple 'Perola' has greater vegetative growth in irrigation depth applied between 67,1 and 79,1% of PAN. The natural flowering cumulative total is greater in depth corresponding to 70% of PAN. The slips production per plant and slips pro- ductivity is greater in depth corresponding to 85% of PAN.

The “araçá” (Psidium spp) is a wild plant with potential for direct and indirect use, and it is found spontaneously in the Semiarid region of the State of Bahia. Thus, the aim of this work was to character- ize and evaluate the genetic diversity for rescuing of 37 accessions of “araça” from the counties of Campo For- moso, Senhor do Bonfim, Jacobina, Morro do Chapéu and Uauá using botanical, morphological and physic- chemical descriptors in plants of different phenological phases. Size of plant, trunk shape, leaf color, floral morphology, fruit transversal diameter, rind color of fruit, fruit mass, fruit longitudinal diameter, fruit shape, soluble solids, titratable acidity, maturation index and C vitamin were the descriptors used. The diversity among the accessions of “araçá” was estimated using the method of Tocher as well as the inverted Tocher start- ing of the integration of data. Three species were determined (P. schenckianum, P. guineense e P. grandi- folium) and it was found great variation for all descriptors used and it was also found plants of the same size of guava plants. Using Tocher and inverted Tocher it was found variation within the same species, among differ- ent species as well as among accessions of different counties and within counties. The descriptors that gave the major contribution were C vitamin (70,88%) and fruit mass (25,66%). The variation found for the descriptors used show that there is genetic diversity among the “araçá” accessions from the five counties of the Semiarid of the State of Bahia and they present potential to be conserved and for future uses.

In aquaculture, infections caused by bacteria are factors that cause damage. The purpose of this study was to identify bacteria with pathogenic potential in pacamã (Lophiosilurus alexandri) of São Francisco Valley. One hundred and fifteen animals were used for sampling from gills, kidneys, external lesions and eggs. The samples were streaked in Trypticase soy agar. The biochemical and antimicrobial susceptibility profiles were determined. The bacterial species identified were A.hydrophila, A. salmonicida, A. media, Acinetobacter spp., P. alcaligenes, E. aerogenes, E. agglomerans, K. oxytoca, K. pneumoniae, P.shigelloides, V. parahaemo- lyticus, V. metschnikovii and S. sannei. The sensitivity to antimicrobial was 85% to norfloxacin, 79% to ceftri- axone, 78% to enrofloxacin, 68% to sulfazothrim, 60% to nitrofurantoin, 59% to tetracycline, 55% to nalidixic acid, 49% to streptomycin, 45% to erythromycin, 32% to neomycin, 7% to ampicillin and 3% to lincomycin. Multiple resistance was observed to all isolates analyzed. Considering the occurrence of pathogenic bacteria in pacamã and its resistance to antimicrobial drugs, security measures should be adopted during antimicrobialther- apy, with the use of antibiotics that did not show resistance strains or trying natural products as an alternative to antibiotics, ensuring protection of human and animal health, as well as the environment.

The effect of plant aqueous extracts in the control of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. the causal agent of guava anthracnose in, was evaluated in vitro with 1, 2 and 3% aqueous ex- tracts of Azadirachta indica, Nerium oleander, Ocimum gratissimum, Syzygium aromaticum. The experiment was installed in a complete randomized desing in a 3x4 factorial scheme (doses x extracts). For the evaluation, it was calculated the percentage of fungal inhibition. The experiment in vivo was conducted by applying Syzy- gium aromaticum and Azadirachta indica aqueous extract at 2 and 3%, respectively, in three different storage conditions: refrigerated with and without plastic film (PVC), and at ambient conditions. The experiment was installed in a completely randomized design, in a 2x3 factorial scheme (extracts x storage conditions). We evaluated the external appearance and severity of disease, loss of weight and Brix degrees. Syzygium aromati- cum extract at 2% provided 100% of fungal mycelial growth inhibition, and Azadirachta indica extract at the highest dosage (3%) inhibited 20.22%. In fruits, there was not significant statistical difference between the ef- fect of extracts on the external appearance and severity of disease, loss of weight and Brix degrees. In relation to the storage conditions, the ones with plastic film and refrigerated differed from the other conditions obtain- ing better external appearance and less severity of disease, lower loss of weight and higher Brix degrees.

Agricultural use of soil resources under irrigated conditions requires constant monitoring of the soil quality attributes due to important soil functions related to soil water storage and distribution, aeration and root growth. The present study aimed to evaluate the impact of citrus cultivation, under irrigated conditions, on the physical quality of a Yellow Ultisol through determination of soil pore size distribution, bulk density and soil water retention, in the Neópolis flat land irrigated perimeter, Sergipe. Soil core samples were collected from the 0-0,10 m, 0,10-0,30 m and 0,30-0,50 m layers, with three replications, in a 15 ha citrus orchard. The same soil type under native forest was also evaluated as a reference of soil quality. It was observed reduction in soil total porosity, macroporosity as well as available water as a function of citrus cultivation. Such alterations in soil physical quality influence negatively root development and plant productivity and also call attention to the need of soil quality monitoring as well as best irrigation management practices. Evaluation of soil quality under native forest was efficient in showing the magnitude of soil alterations as a result of changing in soil use.

The plant species used as ground cover preceding the commercial crops cultivation in the Cerrado must be adapted to the climate and soil of the region, so they have high biomass productivity and offset the decomposition high rates that occurs in these regions. This study aimed to evaluate the biomass yield and the decomposition rate of residues of different cover crops preceding soybean cultivation in Uberaba-MG, Brazil. The experiment was conducted in 2011/12 period in a randomized complete block design in plots with 2 m2 with treatments comprise the following covers: jack bean, millet, sunn hemp and brachiaria. It was evaluated: the dry biomass yield, the decomposition rate through of the bags decomposition, productivity, number of beans per plant, and mass of 100 soybean grains. The millet was the plant cover that showed the highest yield of dry biomass (5.22 Mg ha-1) during the study period. The decomposition of crop residues occurred at accelerated rate until to complete 120 days and after that the rate slowly up until 240 days. Sunn hemp and jack bean were the cover crops with the decomposition highest rates and the smaller half-lives were observed; soybean yield was not affected by the soil covers.

The objective of this study was to evaluate morphophysiologic and productive characteristics from a modern variety of cowpea, cv BRS Novaera, under different plant densities. The experiment was con- ducted out at city of Alvorada do Gurguéia - PI, under irrigation system in the agricultural year 2009/2010. We evaluated five plant populations (100; 200; 300; 400 and 500 thousand plants per hectare) in a randomized complete block design with four replications, using BRS Novaera. The increase in population from 100 thou- sand to 500 thousand plants ha - 1 led to reductions of 78.18% in the number of branches, 66.53% in the number of pods per plant,59.53% in grain yield and, on average,of65.76% and 72.65% for biomass and plantlet af area, respectively. The pod length and weight of on hundred seeds was not significantly influenced by different plant populations. The different plant densities promoted significant changes in morphological and physiological characteristis, yield component sand grain yield.

The scarcity of good quality water in semiarid region has been the main limiting factor for in- creasing the irrigated area. However, due to greater availability of saline water, and reduced costs, when man- aged carefully, can be a viable alternative. The objective of this research was to study the effects of water use with low (S1 = 0,5 dS m-1) and high (S2 = 4,3 dS m-1) salt concentration on growth of melon plant. Melon (Cucumis melo L., cv Sancho) crop was irrigated with water of low and high salinity water under different management strategies: S1S2S2S2 – T1, S1S1S2S2 – T2, S1S1S1S2 – T3, S2S1S2S2 – T4, S2S1S1S2 – T5, S2S2S1S2 – T6 (the 1st, 2nd , 3rd and 4th term of these sequences correspond to different phases of crop – initial growth, flowering, fruit maturation and harvest, respectively), irrigation with S1 water throughout the crop cycle – T7 (control), varying the type of water every two days throughout the cycle (irrigation with S1 during 2 days fol- lowed by S2 1 day – T8 and with S2 during 2 days and followed by S1 1 day – T9) and irrigation with S2 water throughout the cycle - T10. The experiment was conducted in a completely randomized design with four replica- tions. The use of low and high salinity water applied in different phases of plant growth under different man- agement strategies did not affect the characteristics of melon cultivar Sancho. The cultivar Sancho tolerates irrigation water salinity up to 4,3 dS m-1, without any loss in growth and development.