Esterois como indicadores do acúmulo de esgotos domésticos em sedimentos de um sistema estuarino-lagunar tropical (Mundaú-Manguaba, AL)

The history of sewage contamination in the Mundaú-Manguaba estuarine lagoon system (NE Brazilian coastal zone) was evaluated through the concentration of sterols in sediment cores. The concentration of coprostanol increased towards the surface sediments, with the maximum of 5.65 µg g-1 at 0-2 cm sediment layer in Mundaú. Manguaba exhibited a lower level of contamination. The ratio cholestanol/cholesterol suggested degradation of coprostanol only before the burial of organic matter in the sediment. This feature, together with information of population growth in the watershed, allowed the estimation of a sedimentation rate of 0.90 cm year-1 to the Mundaú lagoon.

Optimizing activity of herbicides at reduced rate on Emex spinosa campd. with adjuvants

In pot experiments, two adjuvants were evaluated for their efficacy in enhancing activity of five herbicides applied at reduced rates (75% of the recommended rates) on Emex spinosa at the cotyledon-leaf and at the two- to four- leaf stage. Herbicides (at recommended rates) including fluroxypyr+MCPA at 450 g a.i. ha-1, carfentrazone-ethyl at 20 g a.i. ha-1, bromoxynil+MCPA at 450 g a.i. ha-1, thifensulfuron-methyl at 75 g a.i. ha-1 and tribenuronmethyl at 75 g a.i. ha-1 alone and tank mixed at reduced rates with adjuvants, namely, alkyl ether sulphate sodium salt at 625 mL ha-1 or fatty alcohol ethoxylate at 375 mL ha-1. Addition of the adjuvants to reduced rates of fluroxypyr+MCPA and carfentrazone-ethyl, increased their efficacy with 100% mortality and biomass reduction of E. spinosa at the cotyledon- leaf stage and at the two- to four- leaf stage which was similar to their recommended rates without the adjuvants except for carfentrazone-ethyl at a reduced rate without adjuvants at the two- to four- leaf stage. Bromoxynil+MCPA at reduced rates with alkyl ether sulphate sodium salt also gave 100% control of E. spinosa over weedy check at the two- to four- leaf stage. Both the adjuvants generally increased the efficacy of tribenuron-methyl at reduced rates when sprayed at both leaf stages. These findings suggest that the use of adjuvants may increase the efficacy of the above mentioned herbicides against E. spinosa and it may be incorporated in an integrated weed management program.

WATER USE EFFICIENCY, GROWTH AND YIELD OF WHEAT CULTIVATED UNDER COMPETITION WITH Setaria

ABSTRACT Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.

Sugarcane productivity correlated with physical-chemical attributes to create soil management zone

The socioeconomic importance of sugar cane in Brazil is unquestionable because it is the raw material for the production of ethanol and sugar. The accurate spatial intervention in the management of the crop, resulting zones of soil management, increases productivity as well as its agricultural yields. The spatial and Person's correlations between sugarcane attributes and physico-chemical attributes of a Typic Tropustalf were studied in the growing season of 2009, in Suzanápolis, State of São Paulo, Brazil (20°28'10'' S lat.; 50°49'20'' W long.), in order to obtain the one that best correlates with agricultural productivity. Thus, the geostatistical grid with 120 sampling points was installed to soil and data collection in a plot of 14.6 ha with second crop sugarcane. Due to their substantial and excellent linear and spatial correlations with the productivity of the sugarcane, the population of plants and the organic matter content of the soil, by evidencing substantial correlations, linear and spatial, with the productivity of sugarcane, were indicators of management zones strongly attached to such productivity.

Learning on human resources management in the radiology residency program

Objective To investigate the process of learning on human resource management in the radiology residency program at Escola Paulista de Medicina – Universidade Federal de São Paulo, aiming at improving radiologists' education. Materials and Methods Exploratory study with a quantitative and qualitative approach developed with the faculty staff, preceptors and residents of the program, utilizing a Likert questionnaire (46), taped interviews (18), and categorization based on thematic analysis. Results According to 71% of the participants, residents have clarity about their role in the development of their activities, and 48% said that residents have no opportunity to learn how to manage their work in a multidisciplinary team. Conclusion Isolation at medical records room, little interactivity between sectors with diversified and fixed activities, absence of a previous culture and lack of a training program on human resources management may interfere in the development of skills for the residents' practice. There is a need to review objectives of the medical residency in the field of radiology, incorporating, whenever possible, the commitment to the training of skills related to human resources management thus widening the scope of abilities of the future radiologists.

Spatial influence of physical and chemical parameters on management zone definition in apple orchards

ABSTRACT Precision agriculture adoption in Brazilian apple orchards is still incipient. This study aimed at evaluating the spatial variability of certain soil properties as soil density, soil penetration resistance, electrical conductivity, yield, and fruit quality in an apple orchard through digital mapping, as well as assessing the correlation between these factors by means of geostatistics, establishing management zones. Forty representative points were set within 2.5 hectares of apple orchard, wherein soil samples were collected and analyzed, besides measurements of fruit quality (Brix degree, size or diameter, pulp firmness and color) to generate an overall index quality. We concluded that the fruit quality indexes, when isolated, did not show strong spatial dependence, unlike the index of fruit quality (FQI), derived from a combination of these parameters, allowing orchard planning according to management zones based on quality.

Streamside management zone (SMZ) efficiency in herbicide retention from simulated surface flow

Plot-scale overland flow experiments were conducted to evaluate the efficiency of streamside management zones (SMZs) in retaining herbicides in runoff generated from silvicultural activities. Herbicide retention was evaluated for five different slopes (2, 5, 10, 15, and 20%), two cover conditions (undisturbed O horizon and raked surface), and two periods under contrasting soil moisture conditions (summer dry and winter wet season) and correlated to O horizon and site conditions. Picloram (highly soluble in water) and atrazine (moderately sorbed into soil particles) at concentrations in the range of 55 and 35 µg L-1 and kaolin clay (approximately 5 g L-1) were mixed with 13.000 liters of water and dispersed over the top of 5 x 10 m forested plots. Surface flow was collected 2, 4, 6, and 10 m below the disperser to evaluate the changes in concentration as it moved through the O horizon and surface soil horizon-mixing zone. Results showed that, on average, a 10 m long forested SMZ removed around 25% of the initial concentration of atrazine and was generally ineffective in reducing the more soluble picloram. Retention of picloram was only 6% of the applied quantity. Percentages of mass reduction by infiltration were 36% for atrazine and 20% for picloram. Stronger relationships existed between O horizon depth and atrazine retention than in any other measured variable, suggesting that better solid-solution contact associated with flow through deeper O horizons is more important than either velocity or soil moisture as a determinant of sorption.