MODELAGEM FUZZY PARA AVALIAÇÃO DE MUDAS PRÉ-BROTADAS DE CANA-DE-AÇÚCAR UTILIZANDO DIFERENTES DOSES DE POLÍMEROS E LÂMINAS DE IRRIGAÇÃO

With the increase of the demand for biofuel, Brazil has been globally known as sugarcane productor. Seeking the reduction of costs of that culture, the system of pre-sprouted seedlings is a method that decreases the necessary raw material volume to the planting. Besides, the water is indispensable for the production of that seedling type and to supply that need it is possible to add polymeric to the substratum. Because of that, the present work aimed at analyzing, through a modeling fuzzy, the effects in the formation of pre-sprouted sugarcane seedlings of different polymeric doses mixed with the substratum and different water depth of daily irrigation, 60 days after the planting of the small stalks. Thus, it was used the mathematical modeling of an experiment that took place in a greenhouse in Sao Paulo State Technology College (Fatec). In the fuzzy model developed, the input variables were: polymeric and irrigation. And the output variables studied were: length of the aerial part, aerial part fresh mass, aerial part dry mass, roots fresh mass and roots dry mass. The analysis of polymeric and irrigation effects was accomplished through three-dimensional graphs and maps of the output variables outline. Such modeling aimed at having results also in several points that were not checked experimentally, making possible to analyze all sceneries of the vegetative and physiologic development of such seedlings. It was verified that variables related to the aerial part of the seedlings are positively affected for the addition of polymeric, while the mass of roots has the opposite behavior. In general, it is concluded that the area close to 3 g L-1 of polymeric mixed to the combined substratum with daily irrigation water depth among 10 to 15 mm had the largest answers of the studied biometrics variables. Since it is aimed to have a lower hydric consumption, it is recommended the dosage of 3 g L-1 of polymeric with 10 mm of daily irrigation.