Exchanges of CO2 and changes in content ofC and N were studied over the life of a leaf of Lupius albus L. These data were combined with measurements of C:N weight ratios of xylem (upper stem tracheal) and phloem (petiole) sap to determine net fluxes of C and N between leaf and plant. Phase 1 of leaf development (first 11 days, leaf to one-third area) showed increasing net import ofC and N, with...

Plants were obtained with novel O(2)-resistant photosynthetic characteristics. At low CO(2) (250-350 muL CO(2) L(-1)) and 30 degrees C when O(2) was increased from 1% to 21% to 42%, the ratio of net CO(2) uptake in O(2)-resistant whole plants or leaf discs compared to wild type increased progressively, and this was not related to stomatal opening. Dihaploid plantlets regenerated from anther cul...

It has been theorized that photosynthetic radiation use efficiency (PhRUE) over the course of a day is constant for leaves throughout a canopy if leaf nitrogen content and photosynthetic properties are adapted to local light so that canopy photosynthesis over a day is optimized. To test this hypothesis, 'daily' photosynthesis of individual leaves of Solanum melongena plants was calculated from ...

We have developed a spatially inexplicit model of canopy photosynthesis for balsam fir (Abies balsamea (L.) Mill.) that accounts for key processes of light-shoot interaction including irradiance interception by the shoot, spatial aggregation of shoots into branches and crowns, the differential propagation of diffuse and direct light within the canopy, and an ideal representation of penumbra. Al...

Studies were conducted to quantify leaf area damage to ‘Tahiti’ lime by citrus leafminer (CLM) (PhyllocnistLF citrella Stainton) and to relate leaf damage to larval density and the length of time mining per leaf. Visual estimates of leaf damage were similar among five evaluators and were positively correlated with image analysis determinations. The number of CLM larvae per leaf and the number o...

The mass transfer rate of (14)C-sucrose translocation from sugar beet (Beta vulgaris, L.) leaves was measured over a range of net photosynthesis rates from 0 to 60 milligrams of CO(2) decimeters(-2) hour(-1) under varying conditions of light intensity, CO(2) concentration, and O(2) concentration. The resulting rate of translocation of labeled photosynthate into total sink tissue was a linear fu...

The effects of various chemical treatments upon photosynthesis, soluble leaf protein, CO(2) compensation point, and leaf light transmission in soybean, Glycine max (L.) Merr., seedlings were examined following varying response periods after application at 14 to 17 days postemergence. The compounds N(6)-benzyladenine (BA), 2-(4-chlorophenoxy)-2-methylpropanoic acid (CPMP), (4-chlorophenoxy)aceti...