Determination of Merremia cissoides leaf area using the linear measures of the leaflets = Determina o da 芍rea foliar de Merremia cissoides utilizando dimens es lineares dos fol赤olos

作者：Leonardo Bianco de Carvalho; Silvano Bianco; Valeria Cury Galati; Alan Rodrigo Panosso

来源：Acta Scientiarum - Agronomy, 2011.

• weed
• growth
• roadside woodrose
• linear fit
• planta daninha
• crescimento
• jitirana
• ajuste linear

Knowledge of the weed leaf area may give support to study the interference relationships between weeds and crops. The objective of this research was to determine a mathematical equation for M. cissoides leaf area estimation based on the relationship between theleaf blade linear measures. Leaves of the species were collected from a variety of agroecosystems at S o Paulo State University, Jaboticabal, S o Paulo State, Brazil, measuring the length (L), maximum width (W) and real leaf blade area of the three kinds of leaflets. Linear equations Y = a x (X) were estimated for each kind of leaflet. The confidence intervals of the primary leaflet equation overlapped those ones from the secondary leaflet equation, and then only one equation was considered for these leaflets. So, an equation of principal leaflet plus that one of primary + secondary leaflets were used to determine the M. cissoides leaf area. Thus, the leaf areaof the species might be determined by the sum of the leaf areas of the principal leaflet with the primary + secondary leaflets, according to the equation LAest = 0.501 x (X) + 2.181 x (Z), whereX indicates L x W of the principal leaflet and Z indicates medium L x W of the primary + secondary leaflets, respectively. O conhecimento da 芍rea foliar de plantas daninhas pode auxiliar o estudo das rela es de interfer那ncia entre elas e as culturas agr赤colas. O objetivo desta pesquisa foi determinar uma equa o matem芍tica que estime a 芍rea foliar de Merremia cissoides, a partir darela o entre as dimens es lineares dos limbos foliares. Folhas da esp谷cie foram coletadas de diferentes locais na Universidade Estadual Paulista, Jaboticabal, Estado de S o Paulo, Brasil, medindo-se o comprimento (C), a largura m芍xima (L) e a 芍rea foliar de tr那s tipos de fol赤olos. Foram estimadas equa es lineares Y = a x (X) para cada tipo de fol赤olo. Houve sobreposi o dos intervalos de confian a das equa es dos fol赤olos prim芍rio e secund芍rio, por isso considerou-seuma 迆nica equa o da m谷dia desses fol赤olos, al谷m da equa o do fol赤olo principal, para caracteriza o da 芍rea foliar de M. cissoides. Assim, a 芍rea foliar dessa esp谷cie pode ser estimada pelo somat車rio das 芍reas dos limbos foliares dos fol赤olos principal e prim芍rio + secund芍rio, por meio da equa o AFest = 0,501 x (X) + 2,181 x (Z), em que X indica C x L do fol赤olo principal e Z indica C x L m谷dios dos fol赤olos prim芍rio + secund芍rio, respectivamente.