The reference evapotranspiration (ETo) by Class A pan (TCA) is an indirect method and widely used in Brazil because of its low cost and easy handling. This work it had as objective to determine, for differ- ent methodologies of determination pan coefficients (Kp) that they are proposed in literature, the ETo gotten with the aid of the evaporation Class A pan (ECA), and to compare such results of ETo of Class A pan with the ETo estimated by the FAO Penman-Monteith method which is considered the standard fort the FAO, with his- torical series data of 15 years. There was a good performance of the Class A pan method to estimate the monthly values of ETo, considering the different ways of calculating Kp, and the methodology proposed by Snyder showed the highest rate of concordance (d = 0.80475) and lower mean absolute error (MAE = 0.28452 mm day-1), indicating its potential for practical use on the estimating of daily ETo in the region of Mossoró, Rio Grande do Norte, Brazil.

The growth regulators have been used in different cultures as cultural management technique that aims to reduce the size of the plant and also provide physiological changes that promote increases in grain yield. The objective of the study was to evaluate the effects of paclobutrazol on growth and yield performance of soybeans grown under different plant densities. The experimental design was a randomized block in factorial scheme (2 × 4 × 4), with four replications, two populations of plants (250 and 450.000 plants ha - 1 ), four doses of the plant growth regulator paclobutrazol (0, 12.5, 25.0 and 37.5 g ai ha - 1 ) and four stages of application (V 3 , V 6 , R 1 and V 3 + R 1 ). Averages for the effects of stadiums applications and plant populations underwent Scott Knott test at 5% probability of doses and the regulator to regression analysis. The population of 450.000 pl ha - 1 resulted in greater plant height, lodging and most lower productivity of soybeans. The use of paclobutrazol at V 3 soybean crop did not reduce plant height or grain yield, but reduced the percentage of lodging, and in the stadiums full development of culture (V 6 ) or early reproductive period (R 1 ) reduced height and lodging, as well as the grain yield of the crop. Increases in doses regulator paclobutrazol resulted in reducing plant height, lodg- ing and grain yield of soybean.

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.

Several microorganisms produce polysaccharides, deemed to protect the bacteria from several environmental stresses. This paper aims to evaluate the protective effect of exopolyssacharides to different abi- otic stresses in bacterial isolates from “sabiá” ( Mimosa caesalpiniifolia ) nodules. 303 fast growing isolates were qualitatively evaluated for exopolyssacharide production and tested in vitro for tolerance to two levels of acidity, joint aluminum and acidity, three salinity levels; 11 antibiotics and three herbicides. Most isolates re- sisted media acidity, acidity with aluminum, salinity, and ampicillin, cefotaxime, gentamicin and vancomycin antibiotics and 2,4D herbicide, while being sensitive to ciprofloxacin, chloramphenicol, streptomycin, kanamy- cin, nalidixic acid, rifampicin and tetracycline antibiotics and paraquat and glyphosate herbicides. There was no connection between exopolyssacharide production and abiotic stress tolerance.

The biocontrol of soilborne plant pathogens represents a promising approach from the environ- mental and practical points of view. Fluorescent pseudomonad rhizobacteria are well known by their antagonis- tic capacity towards several plant pathogens due to a diversity of antimicrobial metabolites they produce. This study was conceived to select and characterize rhizobacteria having antagonistic potential towards the patho- genic fungi Rhizoctonia solani and Sclerotium rolfsii. A total of 94 bacterial strains isolated from the rhizospheres of four vegetable species under organic cultivation were evaluated. Twenty-two strains which predominate in lettuce and rudbeckia rhizospheres showed identical biochemical profiles to Pseudomonas fluo- rescens, while in kale and parsley rhizospheres identical profiles to Pseudomonas putida (subgroups A and B) strains prevailed. Two types of antagonism were verified in vitro and defined as competition and inhibition of mycelial growth. Sixty percent of the evaluated strains showed antagonistic potential and, among those, 24 strains expressed antagonism to both target fungi, with P. fluorescens being the most representative bacterial species. This work clearly identified a number of strains with potential for use as plant growth-promoting and biocontrol of the two soilborne fungal pathogens in vegetable crops production systems.

This study aimed to quantify the agro - industrial income and evaluating the quality of cassava minimally processed in minitolete and rubiene shapes. The assays were performed at the Academic Unit of Serra Talhada/ Federal Rural University of Pernambuco. Roots of sweet cassava cv. Mossoró were harvested at 14 months of age, minimally processed in minitolete and rubiene shapes and stored at 5 ± 2 °C and 90 ± 5 % of relative humidity for 11 days. Agroindustrial income, accumulated fresh weight, pH, soluble solids, soluble sugars and cooking time were evaluated. The experimental design was completely randomized in 2x6 factorial design, referring to shapes (minitolete and rubiene) and refrigerated storage times (0, 3, 5, 7, 9 and 11 days), respectively, with 3 replications. The agroindustrial income for each shape was calculated only at the end of minimal processing. The cooking time was measured at 0 and 11 days in 2x2 factorial design. The formats 'minitolete' and 'rubiene' minimally processed sweet cassava showed agroindustrial income above 60%. There- fore, it is suggested the minimum processing of sweet cassava in those shapes. Furthermore, the quality of the shapes was kept preserved throughout the 11 days of refrigerated storage. The 'rubiene' favored higher mean values of soluble sugars giving this format greater sweetness.

The aim of this study was to evaluate the relative expression of three candidate genes, CHIA1, SGF14c and CHS8 * possibly involved in seed quality, in contrasting seed coats from four soybean genotypes. Two genotypes with yellow seed coats, BMX Potência RR and CD 202, and two genotypes with black seed coats, TP and IAC were studied to determine the relative gene expression through the qPCR technique, in sev- en stages of seed coat development for all four genotypes, at 25, 30, 35, 40, 45, 50 and 55 days after anthesis. The CHIA1 and SGF14c genes showed higher expression in cultivar CD 202; the former in the final stages of seed coat development, at 55 days after anthesis, the latter gene at earlier stages, specifically at 25 days after anthesis. The CHS8* gene showed higher expression in CD 202 seed coats at 50 days after anthesis. All three genes expressed at higher levels on genotypes of yellow seed coats, and are considered relevant to new areas of research based on the expression of genes related to seed quality.

The use of natural coagulants and organic filters locally produced and low financial cost can provide attenuation problems in discharge of wastew aters, without treatment, into watercourses. Was ev aluated in this study the efficiency of the coagulation pro cess, using the Ca(OH) 2 in the preparation of Moringa seed extract, followed by filtration sawdust in the trea tment of sewage. In the tank of 150 L containing se wage was added a solution of the moringa seed extract prepar ed with Ca(OH) 2 0.011 mol L -1 at a concentration of 2.2 grams of seed per liter of wastewater to be treated . The coagulated effluent was applied to organic fi lter and the filtrate volume was converted in pore volume. Physi cal and chemical analyses were carried out in the i nfluent and effluent of the two treatment structure for the evaluation of treatment efficiency. The treatments by coagu- lation followed by filtration provided removals of 98.0, 75.3, 75.8, 75.0, 79, 7, 59.0 and 88.3% of tu rbidity, Total Solids, Total Fixed Solids, Total Volatile So lids, Total Suspended Solids, Suspended Solids Fixe d and Volatile Suspended Solids and of 51.2, 88.7, 72.6; 33.5 and 38.5% of Biochemical Oxygen Demand, Chemic al Oxygen Demand, Phosphorus, Nitrogen and Sodium.

The adoption of management practices that reduce water losses is essential to conserve moisture and improve soil temperature, especially in arid and semiarid environments of the Brazilian Northeast, characterized by high evapotranspiration and the adoption of irrigation with saline water, which harms growth and yield of commercial crops. Given these factories, an experiment was conducted in Nova Floresta, Paraíba, from August 2010 to February 2011 in Oxisoil, in order to evaluate the production of bell pepper and soil moisture in grooves with side trim, and application of biofertilizer and mulch cattle. The experimental design was randomized blocks with four replications using a factorial 2 x 2 x 2 for the ground beef with and without biofertilizer, with and without residues of sisal fiber (Agave sisalana), with and without the side facing the grooves, to reduce lateral water losses by infiltration of water with polyethylene plastic film. From the results, the lining of the lateral grooves provided higher values of soil moisture, number of fruits, fruit mass, plant production and productivity, bell pepper plants. It was also found that the combination of biofertilizer and mulch the ground beef remained wetter in the first 15 cm depth.

The cowpea is a plant of great importance for small producers of the Brazilian Northeast, in particular the region of the Vale of Pajeú. The destination of this plant for the production of green beans constitutes an important source of income for family farmers and presents itself as a good alternative for industrial processing. The objective of this study was to evaluate the potential of cultivars of the cowpea for production of green beans in the conditions of Serra Talhada - PE. The experiment was conducted on the campus of Uni- versity Federal Rural of Pernambuco (UFRPE) / Academic Unit of Serra Talhada (UAST) in the period from August to November 2011. We used five developed improved cultivars: BRS-Tucumaque, BRS-Caumé, BRS- Itaim, BRS-Guariba and BRS-Potengi, and three local cultivars: Corujinha, Paulistinha and Sempre-verde. The experimental design was randomized blocks with four replications, where each cultivar was considered a treatment. The characteristics evaluated were: number of days to beginning of flowering (NDIF), plant size (PP), days to maturity of green pods (DMVV), period of production of green pods (PPVV), length of green pods (CVV) number of grains of green pods (NGVV), grain weight of green pods (PGVV), yield of green pods (PRO.VV), productivity of green grains (PRO.GV), index of green grains (IGV). Cultivars BRS-Potengi, BRS- Tucumaque, BRS-Guariba, BRS-Itaim, BRS-Caumé and Paulistinha and showed potential for the production of green beans in Serra Talhada-PE, under irrigated condition.