An attempt has been made to uncouple the effects of the two primary components of shade light, a reduced red to far-red (R/FR) ratio and low photosynthetically active radiation (PAR), on the elongation of the youngest internode of sunflower (Helianthus annuus) seedlings. Maximal internode growth (length and biomass) was induced by a shade light having a reduced R/FR ratio (0.85) under the low P...

Many biomechanical and theoretical studies have been based on the pipe-model theory, according to which a tree is regarded as an assemblage of pipes, each having the same amount of leaf area or leaf mass. However, the physiological mechanisms underlying the theory have not been extensively examined, particularly at the branch level. We analyzed how branches and trunks thickened in nine young Ac...

Studies were conducted to characterize the effect of advanced potato (Solanum tuberosum L.) seed-tuber age on plant growth potential and whole-plant morphology. Plant growth from single-eye seedcores from 5- to 18-month old ;Russet Burbank' seedtubers was compared. Loss in apical dominance was apparent with advanced age. On a per-core basis, the amount of plant dry weight was equal for the two ...

Foliage growth, mass- and area-based leaf nitrogen concentrations (Nm and N a) and specific leaf area (SLA) were surveyed during a complete vegetation cycle for two co-occurring savanna tree species: Crossopteryx febrifuga (Afzel. ex G. Don) Benth. and Cussonia arborea A. Rich. The study was conducted in the natural reserve of Lamto, Ivory Coast, on isolated and clumped trees. Leaf flush occurr...

Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy w...

Sugar Beets (Beta vulgaris L. cv F58-554H1) were cultured hydroponically in growth chambers. Leaf orthophosphate (Pi) levels were varied nutritionally. The effect of decreased leaf phosphate (low-P) status was determined on the diurnal changes in the pool sizes of leaf ribulose 1,5-bisphosphate (RuBP), 3-phosphoglycerate (PGA), triose phosphate, fructose 1,6-bisphosphate, fructose-6-phosphate, ...

Rising temperature and tropospheric ozone (O(3)) concentrations are likely to affect carbon assimilation processes and thus the carbon sink strength of trees. In this study, we investigated the joint action of elevated ozone and temperature on silver birch (Betula pendula) and European aspen (Populus tremula) saplings in field conditions by combining free-air ozone exposure (1.2 × ambient) and ...

a pot experiment was conducted in a completely randomized design with five treatment and five replication, in each replication were 6 plants used. the study of zinc sulphate (znso4) application (20 and 40 ppm) and salicylic acid (sa) application (50 and 150 ppm) was compared to the control (distillated water) on growth and flowering petunia hybrid. for each plant was used 100 cc of solution at ...

this research was carried out on corn in the orzuiyeh region of kerman province over two consecutive seasons (2005-6 to 2007-8). the experiment was done as a split plot with a completely randomized block design and four replications. four levels of consumed water (60%, 80%, 100% water requirement, water use based on regional custom) and three varieties (404sc, 700sc, 704sc) were the main factor...