The role of fructans from leaf sheaths for the refoliation of Lolium perenne after severe defoliation was assessed by following the fate of (13)C-fructose supplied to leaf sheaths at the time of defoliation. At the end of the 4 h labelling period on defoliated plants, 77% of the (13)C incorporated was still located in leaf sheaths. Only 4% and 0.9% were, respectively, allocated to stem and root...

There is concern that cotton gins located in boll weevil, Anthonomus grandis grandis Boheman, eradication zones serving customers in adjacent infested zones may serve as a site for boll weevil reintroductions if weevils are transported alive inside cotton modules. We surveyed fields in three distinct areas of Texas and found that weevils can be present in large numbers in cotton fields that hav...

The flow of carbon into sucrose and starch was investigated in fully expanded primary leaves of spinach using the long to short day transition and partial defoliation as tools to manipulate sucrose/starch synthesis. Transfer from 12 hour to 7 hour photosynthetic periods resulted in a 4-fold increase in the initial rate of starch synthesis, a 50% increase in the initial rate of sucrose synthesis...

We measured diel patterns of stem surface CO 2 efflux ( E s , m mol m 2 s 1 ), sap velocity ( v s , mm s 1 ) and xylem CO 2 concetration ([CO 2 ]) ( X s , %) in 8-year-old loblolly pine trees during the spring to determine how v s and X s influence E s . All trees showed a strong diel hysteresis between E s and stem temperature, where at a given temperature, E s was lower during the day than at...

Drought impacts on forests, including widespread die-off, are likely to increase with future climate change, although the physiological responses of trees to lethal drought are poorly understood. In particular, in situ examinations of carbon starvation and its interactions with and effects on infestation and hydraulic vulnerability are largely lacking. In this study, we conducted a controlled, ...

The aim of the study was to evaluate the impact of defoliation intensity, defoliation frequency, and interactions with N supply on N uptake, N mobilization from and N allocation to roots, adult leaves, and growing leaves. Plants of Lolium perenne were grown under two contrasted N regimes. Defoliation intensity treatments consisted of a range of percentage leaf area removal (0, 25, 50, 75, or 10...

BACKGROUND AND AIMS Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical p...

to study the effects of below leaves excision and nitrogen application on stomatal characteristics of wheat flag leaf, grain protein, dry matter remobilization, grain yield and yield component, leaf area of winter wheat (t. aestivum cv. ghods) was artificially reduced under filed condition. the experimental design was a factorial on a rcb with 3 replications, a combination of three levels of de...

J. Eoon. Entomol. 73: 369-373 (1980) Potato plots were partially defoliated by populations of Leptinotarsa decemlineata (Say) to learn how insect defoliation affected potato yields. The experiment was repeated 7 times at 2·wk intervals throughout the season to determine how plant sensitivity to defoliation changed with plant development. The percent yield reduction of defoliated rows was regres...

The phenomenon of overcompensation has been reported in various plant species although it treated by some as isolated incidents with only limited values. Reviewing reports on the extensive studies defoliation maize showed that different genotypes respond differently to defoliation, varying from phenomenal increase significant loss grain yield. responses kernel yield among are confirmed our expe...