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...

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...

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...

High midday temperatures can depress net photosynthesis. We investigated possible mechanisms underlying this phenomenon in leaves of Eperua grandiflora (Aubl.) Benth. saplings. This tropical tree establishes in small gaps in the rainforest canopy where direct sunlight can raise midday temperatures markedly. We simulated this microclimate in a growth chamber by varying air temperature between 28...

CO(2) exchange between air and leaf is conceived as a current along a resistor with a respiratory current, unaffected by CO(2) concentration, entering the resistor. The conclusion follows that a plant placed in an atmosphere free of CO(2) will increase the CO(2) concentration to the compensation concentration along a curve determined by the resistor and the volume of the atmosphere. This was ve...

Leaf area and its spatial distribution are key canopy parameters needed to model the radiation regime within a forest and to compute the mass and energy exchange between a forest and the atmosphere. A much larger proportion of available net radiation is received at the forest floor in open-canopy forests than in closed-canopy forests. The proportion of ecosystem water vapor exchange (lambda E) ...

application of biofertilizers is a crucial technique for reducing catastrophic effects of irregular utilization of chemical fertilizers. this experiment was carried out to evaluate the effects of rhizobium strains and plant growth promoting rhizobacteria (pgpr) on dry matter partitioning and some growth parameters of chickpea (cicer arientinum l.), arman cultivar. this research was conducted as...