For applications in water management, estimation of evapotranspiration is a critical term in the water balance, to establish a sustainable development of activities that requires such action. So it is necessary to more accurately estimate the reference evapotranspiration (ETo). The objective of this study was to evaluate the performance of daily ETo values obtained for 12 empirical methods by comparing them with the Penman- Monteith FAO. The meteorological data used for the empirical models were measured in the National Institute of Meteorology automatic meteorological station installed at the experimental station in Rafael Fernandes, Federal Rural University of Semi-Arid, Mossoró, RN. Even with some methods presenting divergences from the standard method in the months of the highest water demand with an absolute error of approximately 0.99 to 1.67, it could infer that the most suitable methods based on the performance index greater than 0.76 were: Benevides and Lopez (1970), Linacre (1983), Bruin (1979), Jensen and Hayse (1963) and Priestley and Taylor (1972), in that order, thus it may represent satisfactorily the ETo. The methods that require fewer climatic elements such as Benevides and Lopez (c = 0.85) and Linacre (c = 0.79) performed better than more complex to estimate ETo in daily periods at any time of year.

Anthracnose (Colletotrichum gloeosporioides) and dry rot (Phoma caricae-papayae) of papaya (Carica papaya) reduce fruit post-harvest storage life. Therefore, this study evaluated under laboratory conditions the effect of the hydrothermal treatment of fruits on these diseases. Two types of tests were conducted: (1) fruit immersion in hot water (48 ºC) for 10, 15, 20, 25 and 30 min; and, (2) fruit immersion in hot water at 44, 46, 48 and 50 ºC / 20 min. The experiments were conducted in a randomized complete block design with five replications. Two isolates of C. gloeosporioides and one of P. caricae-papayae were tested in papaya fruits of cv. 'Sunrise Solo' and hybrid ‘Tainung 1’. Fruits were washed, wounded (3mm), inoculated (50μL, 106 conidia mL-1), placed in humid chamber (24 h), and then treated. After treatment, fruits were water cooled (13ºC/20 min) and stored (14 days) in cold chamber (13 ºC; 85-100% R.H.). Daily the diameter of lesions was evaluated for two weeks. Variations on time and temperature did not alter fruit firmness (kg cm-2), pH, total soluble solids (o Brix) e tritable acidity (% of citric acid) in comparison to non-treated fruits. However, in one case on ‘Tainung 1’ fruits, tritable acidity was higher at 48 ºC / 20 min. Fruits treated with hot water at 48 ºC / 20-30 min or 48-50 ºC / 20 min presented less fruit rots.

The indiscriminate use of pesticides is a major environmental problems in the conventional agricultural production systems. The Integrated Production (IP) emphasizes the reduced use of pesticides based on monitoring of pests and diseases. This study aimed to quantify the percentage of reduction in pesticide use in vine growing companies in the region of the São Francisco Submédio Valley after the introduction of IP- Grape. For the survey data were used passbooks field of nine companies in the region checking the number of applications during the production cycle of the years 2006 to 2009, compared to when there was no IP-Grape. In 2006, 2007, 2008 and 2009 decline of 10, 20, 25 and 16% respectively, in the number of fungicide applica- tions, while the spraying of insecticides decreased 99, 95, 93 and 76%. Herbicides had the greatest rationaliza- tion (85%) in 2006, reaching 100% in 2007, 2008 and 2009, in other words from the year 2007. The rationali- zation in acaricides use was not recorded. Thus, the IP-Grape has achieved positive results in relation to the rational use of pesticides.

The objective of this study was to propose monthly average values of Class “A” pan (Kp) for the Pajeu Middle region, as well as analyze the theirs effects in the estimate of agricultural crop evapotranspira- tion (ETc). Evaporation values of class "A" pan and daily weather data from a series of 1999 to 2011 were used. From the daily values of odd-numbered years were obtained monthly values of reference Kp (Kpref). That series was used in the implementation of six methods of estimation of the Kp. The values found have been sub- jected to an analysis of variance and t-test (p > 0.05). The performance of the Kp values was done by estima- tion of the accumulated ETc values of the six agricultural crops. It was verified that the Kpref provided the best statistical indexes and minor errors in the estimate of ETc. The methods of Pereira et al. and the FAO case A should the best estimates among those evaluated. On the other hand, the Snyder and FAO case B methods were those of the worst performances. The performance of the estimation of the ETc in the Middle Pajeu, using the evaporation values of Class "A" pan, is conditioned by the time of year and crop to be explored.

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.

Considering that milk is susceptible to fraud, this study aimed to evaluate the effect of different concentrations of sodium citrate and fortifier in density and freezing point of milk. The addition of citrate in 0.1%, the maximum regulated by Brazilian legislation, was sufficient to decrease the average freezing point for 0.021 °H and increase the density average in 0.0008 g cm - 3 . In these samples was possible to add up to 5.6% water without exceeding the Brazilian standards density and freezing point. The fortifier added to milk in con- centrations higher than 0.05% decreased the average freezing point 0.0024°H compared to the control treat- ment. The average density difference only in the group with addition of 0.44% of tonic, an increase of 0.0034 g cm - 3 compared to the control treatment. However, the dilution recommended by the manufacturer (0.007%) not changed density and freezing point average of milk. The results showed that the addition of citrate in percent- ages permitted by Brazilians law was able to change the freezing point and the density of milk. It should be pointed that in direct UHT process the evaporation of water excess from milk with 0.1% of citrate is based on - 0.530 o H, it is possible that the removal of the incorporated water in UHT process could be incomplete, and can be present in percentages higher than 5%. Thus, the manufacturer recommended concentration of fortifier did not change the density and the freezing point of milk.

The objective was to evaluate the effect of the omission of macronutrient and micronutrient boron in dry matter production, the characterization of the symptoms of nutritional deficiencies and mineral composition in plants of ipeca, an experiment was conducted in greenhouse conditions by the technique the missing element and visual diagnosis. A randomized block experimental design with four repetitions and the treatments were: complete and omissions of N, P, K, Ca, Mg, S and B. The analytical results demonstrated that the production of dry matter was affected in all of the treatments with omission of nutrients and that the ipeca plants presented characteristic symptoms of nutritional deficiencies due to the omissions of N, P, K, Ca, Mg, S and B and the concentrations of the macronutrients and of the micronutrient boron in the different parts of the ipeca plant varied when a certain nutrient was omitted in the solution.

This study evaluated the effects fungicides with or without association with potassium phosphite on the control of the Asian rust (Phakopsora pachyrhizi) of soybean. Two field tests (‘Coodetec- 219RR’ and ‘Emgopa-313’) were conducted (12/2005-4/2006) in Cristalina (Goiás, Brazil), in a complete ran- domized block design (Nine treatments; five replications). The treatments were with one and two applications of phosphite-K (1192 g a.i. ha-1 P2O5 + 596 g a.i. ha-1 K2O) + vegetable oil (VO - 0.5% v v-1), two applications of traditional fungicides (TF) [pyraclostrobin+epoxyconazole (66.5 + 25 g a.i. ha-1); methyl- thiophanate+flutriafol (300+60 g a.i. ha-1); tebuconazole (100 g a.i. ha-1)], and, one application of TF+phosphite and a second application of phosphite+VO. For ‘Emgopa-313’, product applications were made on V8 and R2 soybean growth stage, while for Coodetec-219RR on R1 and R5. Evaluations of disease severity (%DS) were made each seven days after product applications. After the first product application, all treatments significantly reduced DS. At the end of evaluations only treatments with TF significantly reduced DS. Yield and mass of 1000 seeds were significantly higher for treatments with TF. Phosphite-K applications decreased DS, but did not increase yield and mass of 1000 soybean-seeds.

The objective of this study was to evaluate the g rowth of cowpea under the effect of herbicides fomesafen and bentazon + imazamox. The experiment w as conducted in a randomized block design, using th e split-plot scheme. In the plots were evaluated thre e weeds management systems (culture kept weeded by hoe- ing, with application of fomesafen (250 g ha -1 and the mixture of herbicides bentazon + imazamox (1.200 + 56 g ha -1 )) and in the subplots, 10 evaluation periods: 05, 12, 19, 26, 33, 40, 47, 54, 61 and 68 days after em er- gence (DAE). In each evaluation were collected rand omly in two of the four rows of the floor area of t he plots, three plants of cowpea to determine the following c haracteristics: leaf area, dry mass of leaves, stem , pods and total per plant, leaf area index, leaf area ratio, as well as the rates of absolute and relative growt h and of net assimilation. At harvest, we evaluated the number o f plants (stand), number of pods per plant, number of seeds per pod, 100-grain weight and grain yield. The fome safen caused severe intoxication in cowpea, delayin g flow- ering and harvest in seven days, while reducing pro ductivity. The mixture of the herbicides bentazon + ima- zamox did not affect the characteristics related to the growth of cowpea plants as well as the product ion compo- nents.

The vegetation features in the coastal portion of the State of Rio Grande do Norte are presented as transitional environment between Caatinga and Atlantic Forest biomes. Being an area where distinct phytoecological domains overlap and interpenetrate keep their own ecological characteristics. As there are no major human settlements and so little agricultural activities and prominent livestock, natural scenery prevails almost untouched. Because of these characteristics, this stretch of coast has been the target of heavy real estate speculation. This study was aimed to conduct a floristic and structure ecotone study which could contribute to conservation and sustainable use. For the floristic study the entire area (300 ha) was used and the method adopted was the pathway. For the phytosociological characterization a sample from an area of approximately 60 hectares was extracted, which applied the plot method, marking 100 contiguous plots of 100 m2. The phytosociological parameters were calculated using specific software. The floristic recorded 108 species in 91 genera and 49 families. For the phytosociological survey, 1960 individuals comprising of 31 species in 27 genera and 22 botanical families. The most important family was the Myrtaceae. The most abundant species were Psidium oligospermum, Eugenia luschnathiana and Pilosocereus catingicola and endangered species Aspilia procumbens, Cattleya granulosa and Melocactus violaceus. Species from the caatinga and the atlantic forest has been observed, supporting the idea of ecotone.