in order to evaluate competition among some weed species and canola, a field experiment in astan ghods razavi's field in mashhad was done on 2007-2008. thirty 50×50 cm quadrates were used in two times (stem and flower production) to measure the canola dry weight, leaf area index and canola and weeds density with destruction and thirty similar quadrates were used for counting weed species a...

We compared the effects of nitrogen fertilization on shoot hydraulic architecture and leaf photosynthetic properties of Eucalyptus grandis Hill ex Maiden trees in Hawaii. It was hypothesized that water transport capacity would adjust to nutrient availability, with leaf specific hydraulic conductivity (kl) increasing in fertilized trees in coordination with higher photosynthetic capacity per uni...

This study examined how leaf and stem functional traits related to gas exchange and water balance scale with two potential proxies for tree hydraulic architecture: the leaf area:sapwood area ratio (A(L):A(S)) and wood density (rho(w)). We studied the upper crowns of individuals of 15 tropical forest tree species at two sites in Panama with contrasting moisture regimes and forest types. Transpir...

We evaluated drought resistance mechanisms in a drought-tolerant clone (CN5) and a drought-sensitive clone (ST51) of Eucalyptus globulus Labill. based on the responses to drought of some physiological, biophysical and morphological characteristics of container-grown plants, with particular emphasis on root growth and hydraulic properties. Water loss in excess of that supplied to the containers ...

This study was conducted to evaluate the response of Iranian promisinglate blooming almond genotypes to deficit-irrigation stress on GN15 rootstock. One-year old plants subjectedto three deficit-irrigation, including moderate and severe stress (soil water potential, Ψsoil = -0.8 and -1.6 MPa, respectively) and a control treatment (Ψsoil= -0.33 MPa), were applied for six weeks to five grafting c...

Prior studies of a broad array of seed plants have reported strong correlations among leaf life span, specific leaf area, nitrogen concentration, and carbon assimilation rates, which have been interpreted as evidence of coordinated leaf physiological strategies. However, it is not known whether these relationships reflect patterns of evolutionary convergence, or whether they are due to contrast...