The correct management of an irrigation system depends on reliable estimate of reference evapotranspiration (ETo). This paper aimed to evaluate the performance of some empirical equations used to estimate ETo under the climatic conditions of the municipalities of Anagé, Piatã and Ilhéus, located in the Southwest of Bahia State, Brazil. Climatic variables were used for the years 2006 and 2007 obtained through the automatic data collection platform of the Superintendence of Bahia Water Resources / National Institute for Space Research, in which he averaged variables for the two years. To compare the ETo values estimated by methodos of Penman Modificado FAO 24, Radiação, Blaney-Criddlle, Hargreves-Samani, Priestley-Taylor and Turc with the standard method Penman-Monteith (FAO 56) was performed by parameters of regression equation (b), determination coefficient (r²), correlation coefficient (r) estimated standard error (EEP), agreement index (d), index of confidence or performance (c) in daily, three, five and seven days scales. The best methods to estimate ETo for the climatic conditions of the three sites, depending on the indices and parameters studied were by the order: Blaney-Criddle, Penman Modified - FAO 24, FAO 24 Radiation, Turc, Priestly- Taylor and Hargreaves-Samani.

The aim of the present paper was to evaluate the Jathropa curcas L response to different doses of nitrogen, water regimes and soil surface nature. The experiment was conducted from May 2009 to February 2010 under greenhouse conditions at the Sustainable Development Center of the Federal University of Paraiba in Sumé-PB. A factorial experiment in blocks was used with four organic fertilizer (0, 50, 100 and 150 kg of N/ ha), four irrigation levels (50, 75, 100 and 125% the Class A pan evaporation) and four additional treatments with soil mulching. Sixty plastic vases 100 l capacity were used to cultivate the plants during 257 days and a Class A Evaporation Pan was installed in the greenhouse to monitor daily water evaporation. The plant variables evaluated were plant height, stem diameter, leaf area, total aerial and root dry mass. The increase of the soil water content and soil mulching had significant effect on the evaluated plant variables.

The aim was to evaluate the selectivity of insecticides used to control the fall armyworm to epigeic occurring on the soil of a crop of millet. The research was conducted in field in the town of Dourados. The experiment consists of randomized blocks with eight treatments and four replications. Sampling of natural enemies in observable by traps "pitfall modified." The Belt 480 SC insecticide, was not selective family Tachinidae, but was slightly toxic to Formicidae and selective Araneidae and Calossoma granulatum. The insecticide Gallaxy 100 CE, the mortality rate obtained with 63% in the first (DAA) for Araneidae and Tachinidae families, and was selective to a DAA for C. granulatum predator. The insecticide Tracer 480 SC, was not selective to the spiders, Formicidae and Tachinidae. The insecticide Match 50 EC was the most toxic C. granulatum predator and the Spiders in the assessment a DAA, which obtained a mortality rate of 100% and 67% respectively. The effect of the insecticide Karate SC 250, had a mortality rate of families Araneidae and Formicidae, 89 and 60% mortality. The Lannate 215 S to a DAA, its mortality rate for C. granulatum and families Araneidae, Formicidae and Tachinidae 100, 78, 60 and 50%, and selectivity to Tachinidae. The insecticide Talstar 100 EC, was toxic to the Family Formicidae, Araneidae and Tachinidae in the assessment a DAA, which obtained a mortality rate of 80%, 78% and 75% and preserved population of C. granulatum predator.

This paper had as objective to build and to calibrate weight lysimeters of low capacity and to establish comparisons between the working status of constant level water table lysimeters. Two weight lysimeters of 15-L and 50-L and two constant level water table lysimeters of 15-L and 50-L were built at Embrapa Mandioca & Fruticultura Irrigation and Fertirrigation Laboratory, Cruz das Almas - BA, Brazil. Linearity, repetitivity and hysteresis errors in the range of reading of the weight lysimeter. Simultaneously measurements of soil evaporation were performed on bare soil with the two lysimeters in a 1-h interval. Afterwards, orange transpiration was measured by using lysimeters and by using a heat balance sap flow equipment. Results showed that the relation between analogical signals and the standard mass in the lysimeter provided linear equation with reasonable goodness of fit. The systematic and random errors were larger in the lysimeters of larger capacity. The instruments were able to make readings with good stability during the days of measurements and were also able to detect mass variation due to hourly transpiration. However, the measurements were in agreement if comparing average three day data.

The aerial application of pesticides is a valuable tool in agriculture, when based on well-defined technical criterion. This paper aimed to evaluate the spatial dependence of the drops spectrum and its deposition by an aerial application over the soybean crop (Glycine max). An experimental agricultural aircraft was used, model Acrobat, from England Company, equipped with eight rotary atomizers, model Micronair AU 5000, applying a spray volume of 20 L ha-1. To obtain the droplet spectrum were used hidro sensitive targets consisting of paper, distributed in the middle third and higher plants. Spectrum analysis of the drops was made using the computer program "CIR" version 1.5 in 2002. To determine the amount deposited on the leaves of the upper, middle, and bottom of the soybean plants, we used the bright blue food coloring added to the spray solution. These leaves were washed and the amount determined by spectrophotometry. The analysis of spatial dependence was evaluated using the GS + version 7 program. The results show no spatial dependence for the attributes. There was a low percentage of coverage in the upper and middle third of the plants. The geostatistical analysis can be used to characterize the spatial attributes of application coverage, but should be used a sampling grid of smaller size.

The development of soybean cultivars adapted to different regions and generation technologies contribute to Brazil to increase its production, placing it as the second largest world producer and exporter of grain. Several factors have limited its production among these diseases, approximately 40 already identified in Brazil, especially powdery mildew (Erysiphe diffusa U. Braun & S. Takami), one of the most important, resulting in reductions of up to 40% in income susceptible cultivars. The study aimed to evaluate the severity of powdery mildew on soybean genotypes during seven seasons of evaluation, by analyzing disease progress, using regression. It was developed at the Federal University of Viçosa, Minas Gerais arranged in split plots inrandomized block design seven evaluations were performed by visual quantification of the level of infection of leaf area infected (NIAFI). Regression analysis was performed to check the progress of thedisease. The results showed that the method is efficient for such studies, showing clearly the evolution of the disease, and aiding in the discrimination of resistant and susceptible genotypes at the third assessment. Stood out as sources of resistance genotypes UFV-16, UFV-19, UFV 89-361826T2, FT-Abyara RC5 (F4), FT-RC6 Abyara (F2), FT-10 RC5 (F3), Doko RC, UFV UFV 95-4121333 and UFV 94-334268. FT-104 and FT-Crystalina stood out as susceptible and BR-16 and FT-Estrela as highly susceptible, while the other showed intermediate behavior.

The aim of this paper was to evaluate the no-preference for feeding and biological aspects of Spodoptera eridania fed on cowpea cultivars BR17 Gurgueia, BRS Urubuquara, BRS Nova Era, Sempre Verde, BRS Milênio and BR3 Tracuateua. In free-choice test, leaf discs were placed in Petri dishes where one third instar larvae per cultivar was released, whereas in no-choice test one leaf disc was placed per Petri dish where one caterpillar per cultivar was released, evaluating their attractiveness after 1, 3, 5, 10, 15, 30, 60, 120, 360 and 720 minutes, as well as the leaf area consumed. Randomized blocks and complete randomized blocks design were used for free-choice and no-choice tests, respectively, with six treatments and 10 replications. The evaluation of the biological parameters of S. eridania was carried out in Petri dishes where recently hatched caterpillars were transferred in the proportion of one per dish, and the leafs of the cultivars were offered to them during the whole larval period, and we evaluated: periods and viabilities of larvae and pupae, overall viability, weight of larvae and pupae, sex ratio, longevity and overall cycle. Complete randomized design was used with six treatments and 30 replications. In no- preference for feeding free-choice test the cultivars Sempre Verde and BR17 Gurgueia were the most and the least consumed, respectively. Regarding the effects of cowpea cultivars on larval viability we can infer that BRS Urubuquara and Sempre Verde show antibiosis-type resistance to S. eridania.

This paper evaluated the effect of different herbicides applied isolated and mixed on two species of dayflower (Commelina benghalensis and Commelina villosa). Both species were grown under pot conditions with a capacity of 14 L. Three stems with 10 cm were planted per pot. The herbicides application was made using a stationary spray system, to provide a spray volume of 200 L ha-1, with spray tip XR 110.02VS, when the plants were with dimensions of 25-35 cm for C. benghalensis and 30-35 cm for C. villosa. The mixture saflufenacil more effective control of C. benghalensis were saflufenacil + glyphosate (48 + 720 g ha-1) and, saflufenacil + (glyphosate + imazethapyr) with and without the addition of ammonium sulfate (24 + 623 g ha-1). The combination of carfentrazone + glyphosate (20 + 720 g ha-1) were also effective in the C. benghalensis control. The saflufenacil mixture allowed plant control of C. villosa, where saflufenacil + glyphosate (24 + 720 g ha-1) with the addition of ammonium sulfate, showed a good visually control of this species. The application of 2,4-D (720 g ha-1) and 2,4-D + glyphosate (720 + 720 g ha-1) provided the best visual controls of C. benghalensis e C. villosa. All chemical treatment regardless of Commelina species reduced the dry mass of dayflower.

The aim of this study was to evaluate the effect of different freezing times on the physical and chemical properties of goat Saanen breed milk in different the stages lactation L1 (55-65 days); L2 (75-85 days); L3 (95-105 days) and L4 (125-135 days). Three freezing times were tested: -18 ºC (40, 80 and 120 days) and time control (time zero). The stages of lactation of the goats influenced the cryoscopic index, the fat percentages, lactose, protein and total dry extract of the milks samples; nevertheless, the values that were found are between the limits accepted by the law. The results have shown that the milk freezing time did not influence (P<0,05) the density, cryoscopic, fat, lactose, protein and total dry extract parameters of the milk samples. There was an effect of interaction of stages the lactation x the freezing time of the milk (P<0,05) for the pH and acidity, which showed lower values with the increasing freezing time of the milks samples. The freezing time of goat milk proved to be a good means technical of preservation of its physical and chemical components, guaranteeing the product final quality and enabling the delivery the same in periods of low production.

The use of fertigation is becoming increasingly and common, which requires a thorough knowledge about the culture being used. Knowing the uptake is an important point, since this will determine how the split will occur. Among the nutrients of greatest importance to the development of crops are nitrogen (N) and potassium (K). The aim of this paper was to determine the uptake and accumulation of nutrients from cantaloupe melon type "Harper" within the conditions of Mossoró - RN, order for the recommended fertilizer application through drip irrigation. The experiment was in randomized blocks with two replications. The treatments were formed by the combination of increasing levels of nitrogen - N (N1 - 5, N2 - 37.78; N3 - 111.65; N4 - 237.65; N5 - 442.05; N6 - 666.41 kg ha-1) and potassium - K2O (K1 - 5; K2 - 82.86; K3 - 195.67; K4 - 364.61; K5 - 574.13; K6 - 827.54 kg ha-1). We assessed the biomass and accumulation of N, P and K in the plant. The dry matter accumulation in the plant was not affected by levels N and K applied by fertigation. The highest rate of absorption of nutrients occurred around 44 days after transplanting, indicating that this is the time when the plant has increased demand for fertilizer application. Nutrient requirements primary for melon followed the order: K> N> P. To N, the highest accumulation was observed in the vegetative parts (leaf + stem) and the P and K, the highest accumulation was observed in the fruit.