abstract- the evaluation of leaf area and leaf nutritional value is important for crop growth modeling and estimations of its performance. the purpose of this study was to use image processing techniques to develop an economical method to ease the assessment of nutrient status and leaf area (la) of plants and to compare the outcomes of this method with linear models. leaf area and leaf chloroph...

Steady-state leaf gas-exchange parameters and leaf hydraulic conductance were measured on 10 vascular plant species, grown under high light and well-watered conditions, in order to test for evidence of a departure from hydraulic homeostasis within leaves as hydraulic conductance varied across species. The plants ranged from herbaceous crop plants to mature forest trees. Across species, under st...

We examined photosynthetic characteristics of two fast- and two slow-growing half-sib families of both loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii var. elliottii Engelm.) on two sites in northern Florida to: (1) quantify variation in light-saturated net photosynthesis (Amax) associated with vertical crown position and foliage age; (2) quantify the amount and distribution of l...

The sizes and shapes (physiognomy) of fossil leaves are widely applied as proxies for paleoclimatic and paleoecological variables. However, significant improvements to leaf-margin analysis, used for nearly a century to reconstruct mean annual temperature (MAT), have been elusive; also, relationships between physiognomy and many leaf ecological variables have not been quantified. Using the recen...

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...

1. Populations of Metrosideros polymorpha establish across a broad range of precipitation in Hawai‘i – from <400 to >10000 mm per year. To determine whether adjustment of hydraulic and photosynthetic traits could contribute to this success in both high and low rainfall, we sampled populations on the wet and the dry sides of Hawai‘i Island, replicated on two different-aged lava flows at similar ...

abstract the propose of this study was evaluation of cropsyst model on growth simulation and yield stimation of canola under different irrigation treatments. canola (talaye) was sown under 5 treatment and 4 replicants in completed randomized block designs at the college of agriculture, shiraz universityduring 2007-2008. during the growth season dry mass and lai was meseaured frequently, then mo...

The breeding of wheat with greater early vigour has potential to increase water- and nutrient-use efficiency, as well as to improve weed competitiveness to raise crop yields profitably. Given that wheat is inherently conservative in its early growth, a sustained breeding effort was initiated to increase genetically seedling leaf area in developing novel high vigour germplasm. A recurrent select...