RESUMOO uso contínuo do herbicida glifosato pode selecionar biótipos de plantas daninhas resistentes e exigir o desenvolvimento de novas práticas de manejo. Desta forma, o objetivo da proposta foi avaliar a eficácia de diferentes manejos das plantas daninhas na cultura da soja roundup ready, através de herbicidas residuais e pós-emergentes. O experimento foi instalado no delineamento em blocos ao acaso, com 14 tratamentos e quatro repetições e envolveram a aplicação de diclosulam (29,4 g ia ha -1 ) ou sulfentrazone (600 g ia ha -1 ) em mistura com glifosato (712 g ia ha -1 ) e 2,4-D (670 g ia ha -1 ) na dessecação das plantas daninhas, 14 dias antes da semeadura da soja. Posteriormente, foram feitas aplicações de glifosato em pós-emergência nos estádios de desenvolvimento V2 e V4 (356 g ia ha -1 ) ou glifosato aplicado em uma única vez em V2 ou V4 (712 g ia ha -1 ), além das testemunhas sem herbicida e testemunha sem os herbicidas residuais. Atentou-se para a importância de aplicar herbicida residual junto com o glifosato, tanto do ponto de vista de controle de plantas daninhas como em relação ao desenvolvimento da cultura. A adição dos herbicidas diclosulam ou sulfentrazone à dessecação tornou uma única aplicação de glifosato no estádio V4 da soja suficiente. Palavras-chave: glifosato, inibidores da ALS, plantio direto Residual herbicides in weed management in transgenic soybean ABSTRACTThe continued use of glyphosate can select resistant weeds biotypes and tolerant species, suggesting the need to develop new management practices. Thus, the aim of this proposal was to evaluate the effectiveness of different managements in soybean using residual herbicides and post-emergent control of weeds, and observe the possible effects on crop development. The experiment, in the field, was in a randomized block design with four replications and 14 treatments, involving the application of diclosulam (29.4 g ai ha -1 ) and sulfentrazone (600 g ai ha 1 ) and post emergent glifosato (712 g ai ha -1 ) and 2,4-D (670 g ai ha -1 ) in weed desiccation, 14 days before soybean sowing, and treatments with glifosato in soybean stages V2 and V4 (356 g ai ha -1 ) and glifosato applied at a single time in V2 or V4 (712 g ai ha -1 ). We noted the importance of applying residual herbicides with glyphosate to weed control plant, and for the development of culture. The addition of the herbicide sulfentrazone diclosulam or desiccation became a single application of glyphosate in the V4 stage of soybean enough.

In this paper, a daily plan model to the irrigation of a crop field using optimal control was developed. This daily plan model have in consideration: weather data (temperatures, rainfall, wind speed), the type of crop, the location, humidity in the soil at the initial time, the type of soil and the type of irrigation. The aim is to minimise the water used in the irrigation systems ensuring that the field crop is kept in a good state of preservation. MATLAB was used to develop our mathematical model and obtain its output. Its results were compared with experimental ones obtained from a real farm field of grass in Portugal. This comparison not only allowed us to validate our model, but also allowed us to conclude that, using optimal control considerable savings in water resources, while keeping the crop safe are obtained. Some real test cases were simulated and the comparison between the optimised water to be used by the irrigation system (calculated by software) and the real amount of water used in irrigation site (on-off control system for irrigation) produced water savings above 10%.