Leaf area estimatites of custard apple tree progenies

Abstract

Leaf area measurements are required in several agronomical studies. Usually, there is an interest for measurement methods that are simple, quick and that will not destroy the leaf. The objectives of this work were to evaluate leaf area (y), length (l) and width (w) of 20 half-sibling progenies of custard apple tree (Annona squamosa L.), and to fit regression equations of the type y = a + bx, where x = l.w, that will allow y to be estimated based on l and w. The experiment was conducted as random blocks with five replicates and four plants per plot. Five mature leaves were randomly collected from each plant. Leaf area was measured with an automatic measuring device and leaf dimensions were determined with a ruler. All values of b were different from zero. Differences occurred only in 11% of the 190 possible comparison pairs between progenies, with regard to the estimates of b. No differences were observed between progenies with respect to leaf length, width and area. In view of this fact, the equation y = 0.72 x (R² = 0.77) was fitted for all progenies.

Estimativa da área foliar do abacaxizeiro cv. Vitória por meio de relações alométricas

“…Métodos de medição não destrutivos caracterizam-se por estabelecerem relações entre fatores, como área foliar e medições lineares realizadas em folhas, por exemplo. Estes, além de não comprometerem a avaliação de outros parâmetros dependentes da área foliar, reduzem a variabilidade associada a procedimentos de amostragem, bem como permitem que a medida seja realizada várias vezes em diferentes momentos no mesmo indivíduo (LIMA; SILVA et al, 2004).…”

“…Queiroga et al (2003) estimaram a área foliar de feijão-vagem por meio da largura máxima do pecíolo central. Silva et al (2004) desenvolveram equações matemáticas para a estimativa da área foliar da macieira por meio da medição do comprimento e maior largura do limbo foliar. Ramos et al (2008) identificaram equações para a estimativa da área foliar de plantas de pupunheira utilizando a altura, o diâmetro da haste principal, o comprimento e a largura da ráquis foliar.…”

Leaf area estimation in some species of fruit tree by using models as a non-destructive method

“…Also, the plant canopy is damaged, which might affect other measurements or experiments [24]. Non-destructive methods, which do not require the leaves to be detached, are useful because they allow measurements to be repeated during the plant's growth period, and reduce the variability associated with destructive sampling procedures [25]. Recently, new instruments and laser optic apparatuses have been developed for some leaf area measurements [26][27][28][29][30][31][32][33].…”

Non-destructive simple model to estimate the leaf area through midvein in cultivars of Vitis vinifera

“…Generally, in addition to requiring equipment and time to collect and analyze the samples, this type of measurement cannot be repeated many times throughout the cycle due to the reduction of the photosynthetically active area. Non-destructive measurement methods can be more efficient because, besides not compromising the evaluation of other leaf area-dependent parameters, they reduce the variability associated with the sampling procedures (SILVA et al 2004). Non-destructive direct methods consist of portable leaf area integrators, which allow measurements in the field and in real-time.…”