Estimativa de ?rea foliar em gen?tipos de girassol

The leaf area is considered a criterion indicative of productivity. Based on this, methods are easy to perform, non-destructive and fast, which make it possible to estimate this leaf area with precision, thus having high degree of importance, due to enable the observation and evaluation of plant growth in field conditions during the entire cycle. In this present work, the objective was to estimate the leaf area of five genotypes of sunflower in function of the linear measures taken from limbo, and the number of leaves per plant. The experiment was conducted at the experimental area of the Federal University Border South in the period from October 2015 to February 2016. The areas of the limbos, the leaf were determined by direct method and were measured from the length along the main fitting and the width perpendicular to the insertion of limbo in the petiole. For the total area, in addition to the direct method, has been used a destructive method in which the sheets were cut into disks, obtaining regressions for the genotypes and concluded that the best model is the one that uses the product of the linear dimensions, but the models that use only the width are satisfactory in addition to reducing the working time.A ?rea foliar ? considerada um crit?rio indicativo de produtividade. Com base nisso, existem m?todos de f?cil execu??o, n?o destrutivos e r?pidos, que possibilitam estimar essa ?rea foliar com precis?o, assim possuindo alto grau de import?ncia, devido possibilitar a observa??o e a avalia??o do crescimento das plantas em condi??es de campo durante todo ciclo. Nesse presente trabalho, objetivou-se estimar a ?rea foliar de cinco gen?tipos de girassol, em fun??o das medidas lineares realizadas do limbo foliar e m?todos destrutivos do n?mero de folhas por planta. O experimento foi conduzido na ?rea experimental da Universidade Federal Fronteira Sul no per?odo de outubro/2015 a fevereiro/2016. As ?reas dos limbos foliares foram determinadas por m?todo direto e foram mensurados a partir do comprimento ao longo da nervura principal e a largura de forma perpendicular ? inser??o do limbo no pec?olo. Para ?rea total, al?m do m?todo direto, foi utilizado um m?todo destrutivo em que as folhas foram cortadas em discos, obtendo regress?es para os gen?tipos e concluindo que o melhor modelo ? o que utiliza o produto das dimens?es lineares, por?m os modelos que utilizam somente a largura s?o satisfat?rios al?m de reduzir o tempo de trabalho