The use of Silicon on the plants cultivation is one the most used strategy in order to reduce the negative effects of soils salinity. The goal of this work is to evaluate the influence of Silicon on minimizing the negative impacts due to salinity of irrigation water in the Jatropha curcas plants growth. The experiment was carried out at the National Center of Cotton Research, in a completely randomized design and treatments ar- ranged in a factorial 4 x 4 x 6, performed by four levels of salinity of irrigation water (0,43; 2,5; 5,0; and 7,5 dS m - 1 ), four levels of Silicon (0; 221,76; 443,52; and 665,28 mg L - 1 ) and six evaluation periods (40, 55, 70, 85, 100 and 115 days from emergence) with three replications. The analysis of variance, the F test and the polyno- mial regression to 0.05% significance were used to evaluate the data. hight plant, diameter stem plant, number of plant leaves, leaves plant area, total dry matter, dry matter roots plants e dry mass stem plants, dry mass of shoots and roots of Jatropha curcas were not affected by salinity of water at 115 days after sowing. The leaves number and leaf area were influenced by Silicon.

The objective of this study was evaluate the morphological variability and existing production between peanut genotypes collected from small farmers in seven counties in Recôncavo of Bahia, in addition to selecting the most promising materials. Peanut seeds (60 genotypes) were collected along the ethnobotanical survey. Each genotype was collected from a zoned farmer in the study area. Experimental design was a randomized block with four replications. For morphological analysis of growth characteristics were evaluated: main stem height, number of leaves and number of branches also have assessed them components of plant production and productivity, which were evaluated: the volume of fresh and dried vegetable, fresh vegetable pasta and dried, the diameter and length of vegetables, total number of vegetables, total number of grains and the weight of 100 grains. The data were subjected to analysis of variance and means were compared by the Scott- Knott test at 5% probability. Although not shown variability the vegetative morphological characteristics, yield characteristics are indicative of the existence of variability, and why it has become possible to preselect seven peanut genotypes collected from farmers in the Recôncavo of Bahia, which may be considered important descriptors for the distinction of superior genotypes.

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.

Organic fertilizing promotes changes in the physical, chemical and biological attributes of soil making it more productive. The objective of this study was to evaluate the effect of different amounts of hairy woodrose (Merremia aegyptia L.) and their times of incorporation on the chemical attributes of an Alfissol Eutrophic cultivated with lettuce. The experiment was conducted from April to June 2006 at the Universidade Federal Rural do Semi-Árido (UFERSA) in Mossoró-RN. The experimental design was complete randomized blocks with treatments arranged in a 4 x 4 factorial with 3 replications. The first factor consisted of four amounts of hairy woodrose incorporated into the soil (2.2, 4.4, 6.6 and 8.8 t ha-1 dry matter) and the second factor was the four times of their incorporations (0, 10, 20 and 30 days before transplanting lettuce). The soil pH remained alkali, decreasing with the amounts of hairy woodrose incorporated into the soil and with the times of incorporation. The contents of N, Ca and Mg in the soil increased with increasing amounts of hairy woodrose and with the times of incorporation in soil. The levels of available P and K increased with increasing amounts of hairy woodrose incorporated into the soil. However, in relation to the incorporation times, they were optimized at 16 and 14 days, respectively, after the manure incorporation. The utilization of hairy woodrose as organic fertilizer, generally, indicated improvement in soil chemical attributes in relation to the original values evaluated before its incorporation.

The objective of this study was to evaluate the reaction of soybean (Glycine max) cultivars to brown spot (Septoria glycines) under different crop management methods. In this study the effects of the following crop management techniques were evaluated on five soybean cultivars (Msoy9001; Msoy8411; Conquista; Emgopa313; A7002): (a) fungicides and hormones, and; (b) time of planting (October, November and December). The experiment was set in Cristalina, GO, Brazil, in a randomized complete block design with eight replications in a factorial scheme (5 x 3 x 4). The chemical control of brown spot was tested as following: 1) Tetraconazol (T) (0.35 L ha-1) Thiophanate methyl + (TM) (0.4 L ha-1); 2) Stimulate ® [indolbutiric acid 0.005%, kinetin 0009% and giberelic acid (GA3 0.005%) (0.10 L ha-1)] + T (0.35 L / ha) + TM (0.4 L ha-1); 3) T (0.5 L ha-1), and; 4) control without any product. For each plot was evaluated the disease severity and incidence, and yield of seeds. Msoy8411 and Emgopa-313 planted in November presented the lowest amount of disease, and the highest seed yield. Considering the analysis of all cultivars, the chemical treatments that significantly reduced disease were Tetraconazol (0.5 L ha-1) and the chemical combination [Stimulate ® (0.10 L ha-1) + Tetraconazol (0.35 L ha-1) + Thiophanate methyl (0.4 L ha-1)].

Boron deficiency in sunflower cultivation can cause decreased production, mainly by the fall of the inflorescence diameter. Most soils, especially in the tropics present low content of boron (B) available. To ascertain the response of sunflower to boron application in different orders of tropical soils with different tex- tures, we carried out an experiment under controlled condition. Were applied to the soil samples collected in the layer 0-20 cm, four doses of B as boric acid (H3BO3) in solutions at concentrations of 0.0; 0.04; 0.08 and 0.16 mol m-3. The soils were: PAC - Argissolo Acinzentado; PVe - Argissolo Vermelho eutrófico; PVA - Argissolo Vermelho-Amarelo; RL - Neossolo Litólico; RY - Neossolo Flúvico; VX - Vertissolo Háplico. The experimental design used was a randomized blocks in factorial scheme 4 x 6 (doses x soils) with four replica- tions and one plant per pot. Quantification of B content was performed by extraction method with barium chlo- ride solution of 5.0 mol m-3 subjected to heating with microwave radiation and determining the B content in the soil was performed by colorimetric technique using the azomethine-H reagent. The contents at levels sufficient to allow the soil B established independent of the dose added, a yield exceeding 90% yield on. The highest dry matter yield of sunflower was associated with the B concentration in the soil between 0.04 and 0.08 mol m-3 and there was a decrease with higher concentrations.

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.

In massal rearing of natural enemies with the goal of biological control, the procedures adopted for establishment and maintenance of the individual founders of the colonies may have undesirable effects on population genetic structure of laboratory. This situation influences the success of rearing and effectiveness in the field. The objective of this study was to evaluate, along of generations two laboratory populations (Jaboticabal and Piracicaba) of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), founded with different numbers of adults (1, 5, 10, 15 and 20 couples), the frequency of morphological variants, size of wings and eye color, such as parameters for inferences about the homozygosity degrees. For eye color were assessed the frequency, while for the size of wings was measured the width and the length of the right mesothoracic wings. The eye color variants for C. externa populations may be monitored in the laboratory aiming at detecting inbreeding, whereas the measurements of length and width of wings should not be adopted for this purpose.

The aim of this study was to determine the effects of soil management systems in no - tillage system (NTS) and crop rotations and on soil chemical properties. The experiment was conducted for six con- secutive years, during which were made 12 crops (summer and winter). The experimental design was com- pletely randomized in a split plot scheme. Treatments included four soil management (plots): P 1 = NTS fol- lowed annually for a plowing in the winter; P2 = NTS followed biennially for a plowing in the winter; P3 = NTS followed every three years for a plowing and P4 = continuous NTS. Subplots were crop rotation with crops in the summer and winter: R 1 = millet - common bean - millet - common bean - rice - common bean - millet - common bean - millet - common bean - rice - common bean; R 2 = Soybean - common bean - soybean - wheat - rice - soybean - common bean - soybean - wheat - rice - common bean; R 3 = corn - common bean - corn - tomato - rice - common bean - corn - common bean - corn - tomato - rice - common bean; R 4 = millet - soybean - common bean - rice - common bean - millet - soybean - common bean - rice - common bean; R 5 = millet - common bean - corn - common bean - rice - common bean - millet - common bean - corn - common bean - rice - common bean; R 6 = Soybean - common bean - corn – common bean - rice - soybean - corn - common bean - rice - common bean. Each rotation cycle of three years crop season was repeated twice. Systems of soil management and crop rotations significantly affected soil chemical properties. The chemical attributes Ca, Mg, organic matter, P, K, Mn and Zn concentrated in the top- soil regardless of the crop rotation used in the managements of less soil disturbance. The pH values were simi- lar during the 12 seasons in six years. The crop rotations used in different soil managements under NTS provid- ed the improvement of soil fertility with values of organic matter, P, K, Cu, Mn and Zn contents equal to or higher than the initial values.

This study was developed with the purpose of evaluating the protein fractionation and in vitro di- gestibility of the dry matter (IVDMD) of millet genotypes for grazing, managed at different heights and sub- jected to several cuts. The experiment had a randomized complete block design, with repeated measures over time, four replications in a 3x3 factorial arrangement, with three cultivars of millet (ADR 500, LAB 1542 and LAB 1838) and three average cutting heights (60; 80 and 100 cm). Evaluations were undertaken through cuts in the same plots during four months. Results showed that millet genotypes were similar as for the values of pro- tein fractionation and IVDMD. The forage quality is affected by the management of cutting height, thereby it is not recommended to manage millet genotypes at 100 cm height for providing lower fraction A, B1, B2 and digestibility and higher fraction B3 and C of the forage.