-Volatilization plays an important role in the process of herbicide dispersion in the environment. The physicochemical characteristics of the clomazone molecule indicate its volatility potential. The present study aimed to evaluate the volatilization rate of three clomazone formulations under field conditions using indicator plants and wind tunnels. Transparent polyethylene tunnels were placed on a sorghum (Sorghum bicolor) field parallel to the prevalent wind direction, and the herbicide formulations were applied in plastic trays containing 10 kg of sieved soil and placed at the center of the tunnel. The experiment was arranged in a slip-plot design with four replications. The main plots were represented by different formulations of the herbicides: Gamit 360 CS ® , Gamit 500 EC ® and Gamit Star ® , and control plots without herbicide application. The sub-plots represented the distances from the application site: 1, 2, 3, 4, 5, 6 meters. Herbicide injury in sorghum was then assessed at different days after application. The symptoms of all formulations were more intense in the plants that were closer to the application site, and were even more severe in the prevailing wind direction. In general, regardless of the application distance, Gamit 360 CS ® caused less injury to the sorghum.

-Volatilization represents an important process in the displacement of pesticides for the environment. The physicochemical properties of the clomazone molecule indicate its relative volatility. Therefore, this study was carried out to assess the volatilization of different clomazone herbicide formulations using bioindicator species. To that end, airtight glass boxes were used with the presence of different clomazone formulations and plant species. The formulations used were Gamit 360 CS ®

Since its beginning in 1993, FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) has established a number of work groups to develop procedures for estimating concentrations of plant protection products and their metabolites in various environmental compartments (ground water, surface water, soil, sediment, and air). One of the most important parameters in these environmental assessments is the degradation of these compounds. Although the procedures for conducting the laboratory and field studies measuring degradation are specified in study guidelines, the procedures for calculating degradation rates have not been standardised. The general procedures for calculating degradation rates are well known but the assumptions made during this process can appreciably affect the results. Therefore FOCUS established a work group of experts from regulatory authorities, research institutes, and industry to develop recommendations for calculating degradation kinetics in the EU registration process. This FOCUS group met nine times between September 2002 and January 2005, carefully considered the comments of the member states to an initial draft of its findings, and prepared version 1.0 of this report in In response to the comments made by the EFSA PPR Panel, the FOCUS Steering Committee (SC) asked the work group to produce this final version (version 2.0) of the report.The SC reacts to the recommendations by the Panel as follows:(1a) This chapter was not part of the remit of this work group and would lead to a considerable delay in the finalisation of this guidance document which the SC considers undesirable. Therefore the SC decided not to follow this recommendation.However, new Section 11.5 was added to the guidance document that gives some reflections on this matter. (4) Several companies have taken the initiative to develop such software, which is expected to become available in 2006. However, the guidance described in the report has been designed to be generally applicable, independent of specific software tools.(5) The SC agrees that reviewing such experiences is necessary. However, the first step is to collect and report these experiences systematically. The SC cannot commit a FOCUS work group to this task because such experiences are gained in the EU risk assessment procedure co-ordinated by the EFSA PRAPeR team. The SC suggests therefore that this team collects and reports these experiences.The calculation of kinetic parameters is a fundamental component of environmental risk assessments of plant protection products. The recommendations of this report can and will impact the evaluation process. These impacts include more complex evaluation processes, more detailed documentation of calculations, and potentially the need to conduct additional experimental studies. Therefore, the FOCUS Steering Committee recommends the following Page 5 phased approach to the introduction of the recommendations: All regulatory studies that include estimation of degradation kinetics completed later than nine months a...

-The objective of this research was to evaluate the occurance of multiple resistance of Sagittaria montevidensis (SAGMO) biotypes to acetolactate synthase (ALS) and photosystem II (PSII) inhibiting herbicides through dose-response experiments. The experiment was conducted in a greenhouse from October 2012 to March 2013, in Pelotas, RS. The experimental design was completely randomized, with four replications. Treatments were arranged in a triple factorial design: two biotypes of S. montevidensis (SAGMO 35 -susceptible to herbicides and SAGMO 32 -suspected to be multiple resistance to ALS and PSII inhibiting herbicides), four herbicides (penoxsulam, (imazethapyr+imazapic), bentazon and saflufenacil) and 8 rates of these herbicides (1/32x, 1/16x, 1/8x, 1/4x, 1/2x, 0x, 1x, 2x, 4x, 8x, 16x, 32x and 64x). SAGMO 32 biotype presented high levels of resistance to penoxsulam, (imazethapyr+imazapic) and bentazon. For a 50% reduction in dry matter of the resistant biotype rate of 138 and 2.46 times higher than the label required for the susceptible biotype of the herbicides (imazethapyr+imazapic) and bentazon, respectively, are required. Saflufenacil may be used successfully to control Sagittaria montevidensis resistant in irrigated rice.

Soma térmica de subperíodos do desenvolvimento da planta de melancia Thermal time of developmental phases in watermelon RESUMOA temperatura do ar é um dos elementos meteorológicos mais importantes que afetam o desenvolvimento da planta de melancia. Para representar o efeito da temperatura do ar sobre o desenvolvimento das plantas, temse usado o método da soma térmica, por ser um método simples e por ser uma melhor medida de tempo biológico que dias do calendário civil ou dias após a semeadura. O objetivo deste trabalho foi determinar a soma térmica de três subperíodos de desenvolvimento da planta de melancia por diferentes métodos de cálculo. Um experimento em campo foi conduzido em Santa Maria, RS, com duas datas de semeadura durante o ano agrícola 2006-2007 (05/09/2006 e 21/09/2006). Usou-se a cultivar "Crimson Sweet" no delineamento experimental de blocos ao acaso com seis repetições. Os subperíodos foram semeadura-emergência (SE-EM), emergência-florescimento (EM-FL) e florescimento-colheita (FL-CO). A soma térmica diária (STd, ºC dia) foi calculada por três métodos considerando-se as temperaturas cardinais de 10°C, 33°C e 42°C. A soma térmica acumulada (STa, ºC dia) para os três subperíodos foi calculada somando-se os valores de STd. Não se constatou diferença na duração (STa) do ciclo total e dos subperíodos entre os três métodos de soma térmica utilizados. A duração (STa) do subperíodo EM-FL foi similar nas duas datas de semeadura (417ºC dia), mas a STa dos subperíodos SE-EM e FL-CO variou de 98 a 130ºC e de 770 a 840ºC dia, respectivamente.