Allelopathy can be defined as any effect , direct or indirect, beneficial or harmful, a plant on the other, through the release of chemical compounds into the environment. Thus, this study aimed at evaluat- ing, in the laboratory, allelopathic effects of aqueous extracts from cover crops as canola (Brassica napus L. var), crambe (Crambe abyssinica Hochst), sunn hemp (Crotalaria juncea), linseed (Linum usitatissimum L.) and forage turnip (Raphanus sativus L.) at 0, 12.5, 25, 50 and 100% concentrations. The plants used in aqueous extracts were collected during their flowering period of each studied species. Germination tests were performed on seeds gerbox, fresh and dry seedlings biomass, root and shoots seedlings length. The experimental design was completely randomized (CRD) in factorial (5x5) with four replicates per treatment. According to these results, it can be concluded that the tested extracts showed allelopathic effect on seedlings of lettuce, cucumber and soybean on almost all parameters, but for soybean germination and dry mass percentage, this effect was not significant. The sunn hemp extract, despite concentration, contributed the most to increased germination and seedling growth. However, linseed extract showed opposite effect for these parameters in 100% concentrations.

The present work studied the productivity of plant and ratoon cane in soils with different physical, chemical and mineralogical particulars submitted to phosphate fertilization. Randomized block field experi- ments were located at Japungu Distillery (Paraíba State), at Sugar Cane Experimental Station of Carpina (Pernambuco State) and at Bom Jesus Sugar Cane plant (Pernambuco State), from where Argisoils of sandy, mid and clayey textures were selected respectively. The doses of 0, 40, 80, 120, 160 and 200 kg ha - 1 P 2 O 5 were applied at the bottom of the furrow (fertilization foundation). In the subsequent ratoon cane were applied 0 and 40 kg ha - 1 P 2 O 5 (topdressing) for each of the doses applied at the planting. It was concluded in this study that the productivity of sugarcane plant was positively influenced by phosphorus fertilization planting. The ratoon cane only responded nicely to phosphorus coverage in the less weathered medium texture Argisoils; Phospho- rus fertilization of ratoon sugarcane coverage in clay and weathered Argissolos did not promote increased productivity, restricting its recommendation in Argissolos with these characteristics.

It characterization of the variability of soil attributes is necessary so that we can interpret the possible causes of variations in crop yields, because the soil has, naturally, heterogeneity its attributes. Thus, the objective of this study was analyze the spatial variability and dependecy, through the tool GS+, the physical attributes of a typic fluvia underwent two systems use and management of soil: disking and mowing lines. The area managed by disking for over 10 years has 0.5 ha and the area mowing between the lines 13 years ago has 2.3 ha both located on the systematic plan of Experimental Farm in the Valley Curu, Pentecoste. Soil samples were taken in both disturbed and undisturbed areas obeying the spacing of 15 x 15 m, 21 in the area with har- rowing and 78 in the area by mowing between the rows. The density was the only attribute which there wasn’t spatial dependence structure. The other attributes (sand, clay, silt, micro and macroporosity and gravimetric soil moisture and the mechanical resistance to penetration) showed spatial dependence of medium until high. It was observed in the mowing area is made between the lines showed lower values macroporosity and high penetra- tion resistance, the constraint condition for the growth of roots.

This paper describes the composition of fatty acids in oil extracted from seeds of carnaúba ( Copernicia prunifera (Miller) H. E. Moore), an important palm species native to Northeastern Brazil. After extracting the crude oil, the physico - chemical characteristics (density, refraction index, pH, acidity and saponi- fication index) were registered and the chemical composition of the fatty acids was determined by gas chroma- tography (GC - FID). The predominance of saturated fatty acids does not make carnaúba seed oil a promising alternative for the food industry, and the small yield obtained (approx. 5%) may constitute a limiting factor for commercial exploitation, but carnauba seed oil could potentially be used in the production of biofuels, cosmet- ics and detergents.

Drip irrigation is one of the most efficient method s forapplyingwaterto a crop, capable of deliv- ering water at a rate close to the demand. Many eff orts have been required to estimate the amount of w ater needed by plants. Therefore studying soil water ext raction by plants linked to mathematical modeling f or be- havior prediction, and linked to computational reso urces to allow complex mathematical procedures to b e real- ized in a short space of time, becomes a powerful a nd necessary alternative for the understanding and quantifi- cation of the involved processes. Simulations were performed through a computational model, with the purpose of estimating the crop coefficient (K c ) of watermelon in the region of Mossoró-RN, using a three-dimensional macroscopic root water uptake model, which solves t he sink term of the Richards equation. The simulati ons results were compared with an experiment that estim ated the K c using lysimeter. The results of Kc estimated by the model showed a good agreement with lysimeter re sults in all chosen statistical indexes, indicating that the model can serve as a tool for predicting transpirat ion and evaporation of soil water under certain con ditions, and as a tool to aid the irrigation management.

The aim of this work was compare the buffaloes and cow’s milk quality. The samples were from cross buffaloes (Jaffarabadi x Murrah) and cow’s (Frisian x Zebu), collected from 2012 April to June.Was determined milk chemical composition (lactose, fat, protein, total solid and milk solids), physical characteris- tics (pH, density and milk acidity). The data were submitted to variance analyze, using F - test (P<0.05). The buffaloes present more level of the fat, protein, lactose, milk solids than cows. In relations to hipercholester- olemics fatty acids, the buffaloes presented hight level to the C16:0 and Lower levels of c12 and c14 than cows. Higher levels to the vacenic and rumenic acid were observed in buffaloes Milk than cows. In spite of a higher content of saturated fatty acids, the milk of water buffaloes showed lower ratio n6/n3 and lower choles- terol when compared to cow. The milk of buffalo and cow showed adequate nutritionally These results indi- cate the need for the creation of specific legislation for the buffalo milk.

The undesirable effects of agrotoxics have aroused the interest of society to use alternative tactics of pest control, as plants with insecticidal activity, which can be used as powders, aqueous and organic extracts, essential oils and emulsifiable. This way, the toxicity, population growth and repellence of aqueous extracts of plants were evaluated on the cassava green mite, Mononychellus tanajoa . Aqueous extracts of Cro- ton blanchetianus , Myracrodruon urundeuva and Ziziphus joazeiro were used, in which were immersed in cas- sava leaf discs (3.5 cm diameter). The extracts at all concentrations (1, 5, 10, 15, 20 and 25%) resulted in a de- cline in the pest population. The concentrations of 20 and 25% of the extracts resulted in the highest percentage mortality of the pest. All extracts in concentrations of 15, 20 and 25% for adult females were repellents M. ta- najoa .

The rio Doce river basin has great silvicultural potential, areas cultivated with pasture are con- verted to forest plantations. Physical processes in the soil, especially the infiltration water, are very dependent on the type and management of its coverage. The objective of the present study was to evaluate the differences between rates of water infiltration in soils submitted to eucalyptus plantations and pasture and adjust empirical models of infiltration. The experiment was conducted at four sites in the Rio Doce river basin, MG, Brazil, where two were planted with eucalyptus and two with pasture. Five infiltration tests using the concentric rings method were performed in each area. Results show that the soils infiltration rate with eucalyptus plantations were higher than those found in soils from pasture areas, with stable infiltration rates of 78 and 165 mm h-1 in eucalyptus and 47 and 50 mm h-1 in pasture. The model of Horton indicated the highest adjusted confidence index for the four sites analyzed.

The optimization of nutritional efficiency is critical to increase productivity and reduce produc- tion costs. However, the identification of lines with greater efficiency and responsiveness to phosphorus is of great importance, with the in intention to join the hybrid, these traits at once and, moreover, the best way to select them. Thus, the objective of this study was to evaluate which characters should be considered in the se- lection of genotypes efficient and responsive to phosphorus in sorghum. The correlations were split into direct and indirect basic variables of efficiency and responsiveness to phosphorus through path analysis. The character that most influenced the efficiency of sorghum lines to phosphorus was harvest index to utilization efficien- cy and dry matter to absorption efficiency and use, under conditions of stress. Under conditions of adequate phosphorus fertilization, the trait with the greatest influence for evaluation of responsiveness was dry grain mass to the apparent recovery efficiency, physiological and agronomic.

The Caatinga biome covers a vast area in northeastern Brazil and presents a high level of biodiversity. It is known that about 400 plant species are used by semi-arid local communities for medical purposes. Based on ethnopharmacological reports, this study aims to screen 24 species from Caatinga regarding the ability to prevent biofilm formation and to inhibit the growth of Pseudomonas aeruginosa - a major opportunistic human pathogen and an important causative agent of morbidity and mortality. The effects of aqueous extracts, at 0.4 and 4.0 mg mL-1, on biofilm formation and on growth of P. aeruginosa ATCC 27853 were studied using the crystal violet assay and the OD600 absorbance, respectively. The most active extracts were analyzed by thinlayer chromatography and high performance liquid chromatography. Our investigation pointed extracts of four species with potential application for the control of P. aeruginosa: Anadenanthera colubrina (Vell.) Brenan, Commiphora leptophloeos (Mart.) J.B. Gillett, Myracrodruoun urundeuva Allemão, whose antibiofilm effects (89%, 56% and 79% inhibition of biofilm, respectively) were associated with complete inhibition of bacterial growth, and Pityrocarpa moniliformis (Benth.) Luckow & R.W. Jobson, which were able avoid 68% of biofilm formation and inhibited 30% bacterial growth. The qualitative phytochemical analyses reveal the complexity of the samples as well as the presence of compounds with high molecular weight.