In order to evaluate the sensitivity of citrus g enotypes: ‘Santa Cruz Rangpur’ lime, ‘Sunki Tropical’ mandarin, ‘Troyer’ citrange, ‘Volkamer’ l emon, and HTR-051 and HTR-069 trifoliate hybrids to salinity during the rootstock formation period in g reenhouse. The genotypes were subjected to five lev els of irrigation water salinity: control, tap water with electrical conductivity (EC w ) of 0.41 dS m -1 and water with EC w of 1.0, 2.0, 3.0 and 4.0 dS m -1 , made from salts NaCl, CaCl 2 .2H 2 O e MgCl 2 .6H 2 O, using the 7:2:1 propor- tion, respectively. The ‘genotypes’ and ‘salinity’ factors were arranged in factorial design (6x5), us ing a ran- domized block, with five blocks and four plants per parcel. The growth and physiological variables wer e evalu- ated registering the most significant effects to sa linity on total dry matter at all genotypes, highli ghting total dry matter accumulation in 'Volkamer' lemon and the hig hest decrease from increasing salinity it is observ ed in 'Troyer' citrange. The 'Volkamer' lemon and HTR – 0 69 can be recommended to formation of seedlings of cit- rus rootstocks under salinity due to its less sensi tivity in the formation of biomass.

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.

Culturas de cobertura são usadas para cobrir o solo e também podem liberar nitrogênio para o solo durante a mineralização. No entanto, é necessário identificar espécies que combinem liberação rápida de nutri- entes com maior persistência da palhada na superfície do solo. O objetivo deste estudo foi investigar a degrada- ção da palha e a liberação de nitrogênio por culturas de cobertura sob plantio direto. O experimento de campo foi conduzido durante dois anos no verão (2008/2009 e 2009/2010) na região do Cerrado do Brasil. O delinea- mento experimental foi em blocos ao acaso no esquema fatorial. Os tratamentos foram a combinação de cinco plantas (quatro espécies de plantas de cobertura 1- Panicum maximum, 2- Brachiaria ruziziensis, 3- Brachiaria brizantha e 4- Pennisetum glaucum [milheto] e pousio como controle) com seis épocas de avaliação (seis pri- meiras semanas após a aplicação de glifosato nessas plantas de cobertura). Entre as espécies avaliadas, Penise- tum glaucum e pousio tiveram rápida degradação da palhada e liberação de nitrogênio. As culturas de cobertura Panicum maximum, Brachiaria brizantha e Brachiaria ruziziensis se destacaram na produção de biomassa e na quantidade de nitrogênio nas suas palhadas, mas apresentaram baixos coeficientes de degradação e persistiram por mais tempo na superfície do solo em relação a Pennisetum glaucum e pousio.

The use of compatible rootstocks, besides protecting sensive plant risk of soil- borne pathogens, can increase the yield and improve the quality of the fruit. The study aimed evaluated compatibility, yield and fruit quality of rootstocks and seedless watermelon. The experimental design was randomized blocks, with a 2x3 (two varieties of seedless watermelon: Shadow and RWT8154; three type of root system: without rootstock and upon BGCIA229 and BGCIA941, selected for their resistance/tolerance to nematodes and/or Fusarium spp) with four blocks and six plants/plot. The grafting method was approaching. Hipocotyl diameter of seed- lings of ‘Shadow' was similar to BGCIA229, and 'RWT8154' to BGCIA941. Verified a hight compatibility in combinations 'RWT8154' with BGCIA941 and BGCIA229. Through grafting it was found: Higher survival was observed in 'Shadow' grafted on BGCIA229. increased vegetative growth of 'Shadow' and reduction in 'RWT8154'; delayed of the 'RWT8154' female flowering; increase in fresh plant weight; increase in the yield of 'RWT8154', and reduction in 'Shadow'; increased fruit weight in 'Shadow' grafted on BGCIA229 and 'RWT8154' grafted on BGCIA941; increase in 'RWT8154' peel thickness; greatest firmness; increase in bright- ness and color intensity of the 'Shadow' pulp. The titratable acidity of the cultivars increased and that the SS/ TA ratio decreased in the tested combinations. So there is specificity among cultivars and rootstocks. The com- bination 'RWT 8154' grafted on rootstock BGCIA 941 provided higher yield and fruit quality.

The management when done so improperly can cause changes in the physical, chemical and biological soil properties. The aim of this study was to evaluate the behavior of physical attributes in a dystrophic Oxisol under different vegetation covers and managements in the city of Chain southern state of Piauí. The experimental design was randomized using a split-plot with four types of cropping systems and four sampling depths, with three replications. Cropping systems were studied: Nim (Azadirachta indica), elephant grass (Pennisetum purpureum), Brachiaria decumbens and Native Forest sampling depths 0-0.10, 0.10-0.20, 0.20-0, 30 and 0.30-0.40 m. The effects of hedges and management on soil physical properties in different soil depths were recorded from the analysis of variance and treatment means compared by Tukey p <0.05. Determinations were carried out density, macroporosity, microporosity, total porosity, and resistance to penetration in all cropping systems. The elephant grass and native forest had the lowest values of penetration resistance and bulk density, higher values of total porosity and macroporosity, reflecting better physical condition of the soil. The area with Nim and Brachiaria was influenced by animal trampling, thus causing increase of soil density and hence the resistance to penetration.

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 Ceara State has a variety of species of non-traditional fruits that are consumed in natura and/or processed by local population, with economic potential for agro-industrial processing, however, still poorly studied. In this context, the aim of this research was to evaluate the genetic variability of puçazeiro ‘Coroa de Frade’, native tree from coastal vegetation of Beberibe, Ceará, Brazil, by physico-chemical and chemical characteristics of their fruits. Fifteen genotypes were evaluated. The traits analyzed were: soluble solids (SS), titrable acidity (TA) (% of citric acid), pH, SS/TA ratio, total sugars, reducing sugars, starch and, total and soluble pectin. The genotypes were characterized as a good alternative to the market of exotic fruits, showing high values of SS (20,40 a 31,00 °Brix) and low mean values of titrable acidity (0,27 a 0,58 % of citric acid), producing SS/TA ratio ranged between 37,5 and 102,43, with emphasis on the genotype '8', which pre- sented SS/TA ratio of 95.05. The genotypes showed fruit netting with high starch (> 1%). The values of total pectin (0.35 to 0.98%) and soluble pectin (0.13 to 0.74%) reinforcing the use of this fruits in the industry, with low cost to manufacture of candy and jellies. The repeatability analysis showed that most of the observed varia- tion among genotypes is associated with the genetic component. Therefore, it can be concluded that the studied genotypes of puçazeiro 'Coroa de Frade' showed wide genetic variability and have fruits indicated even for fresh consumption as well as for processing.

The study assessed sensorial aspects and physicochemical characteristics of two non- commercial genotypes of cherry tomato, CH152 and CLN1561, and compared them to the genotype Carolina, all grown organically. Ripened fruits of the three varieties were harvested at the same time, selected, cleaned and subjected to sensorial analysis by 50 adult testers. They used a 9-point hedonic scale to classify the fruits in terms of aroma, flavor, flesh color and general appearance. The physicochemical analyses determined pH, solu- ble solids (SS) and titratable acidity (AT). For the aspects aroma and general appearance, the 3 varieties ob- tained mean scores of 7.0 to 7.9, which corresponds to “like moderately”; and scored 8.0 to 8.9 to the attribute flesh color, which represents “like very much”. For the attribute flavor, the scores of “Carolina” tomatoes and CLN1561A corresponded to “like moderately, and for CH152 it was “like very much”. The mean values of physicochemical parameters (pH = 4.41 to 4.61; SS = 4.03 to 5.06; and AT = 335.13 to 369.23) were similar among the genotypes (ANOVA, P>0.05). In conclusion, both the varieties tested, CH152 and CLN1561, pro- duce fruits of high sensorial and physicochemical quality, showing potential for commercial exploitation.

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.

Due to the oil crisis and concern about the environment, global demand for biofuels has ex- panded rapidly in recent years, so the physic nut has attracted the attention of researchers for the development of research on this specie. The aim of the present work was to verify the effects of the supply of Na to replace potassium nutrition on growth and nutrition of physic nut seedlings. The experiment was conducted in green- house conditions using nutrient solution. We used the completely randomized design in five proportions of replacing K by Na: 100% (T1), 75% (T2), 50% (T3), 25% (T4) and 0% (T5). Thus, the concentrations (in mM) of K:Na in the treatments were: T1 = 0:6.0; T2 = 1.5:4.5; T3 = 3.0:3.0; T4 = 4.5:1.5; T5 = 6.0:0. The sources of K and Na used were KNO3 and NaNO3, respectively. Data were subjected to analysis of variance and means evaluated at Scott & Knott test at 5% probability. The growth and mineral nutrition variables of physic nut seedlings are influenced by the substitution of K by Na, varying according to the characteristic studied. Na re- places partially the K nutrition of physic nut seedlings and establishing a strategy to reduce the doses of K fer- tilizer applied.