Use of an analytical model to study limitations on net photosynthesis in Arbutus unedo under field conditions

Oecologia ◽  
1986 ◽  
Vol 70 (3) ◽  
pp. 393-401 ◽  
Author(s):  
P. C. Harley ◽  
J. D. Tenhunen ◽  
O. L. Lange
Keyword(s):  
Analytical Model ◽  
Net Photosynthesis ◽  
Field Conditions ◽  
Arbutus Unedo

Design and testing of twig chambers for ozone fumigation and gas exchange measurements in mature trees

1994 ◽  
Vol 102 ◽  
pp. 541-546 ◽  
Author(s):  
Wilhelm M. Havranek ◽  
Gerhard Wieser
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Ambient Air ◽  
Field Conditions ◽  
Chamber System ◽  
Mature Trees ◽  
Diurnal Courses ◽  
Controlled Conditions ◽  
Design And Testing

SynopsisA twig chamber system was developed for the exposure of mature trees to ozone (O3) under field conditions. The fumigation system allowed the exact control of O3 concentrations in the chambers, the measurement of O3 uptake as well as gas exchange measurements under ambient and controlled conditions during and after O3 fumigation. Because of differences in individual twigs the system should provide the exposure of replicates to different O3 treatments. Tests showed that temperature, humidity and O3 concentrations inside the chambers were comparable with diurnal courses observed in the field. Comparative gas exchange measurements indicated that there were no differences in net photosynthesis and conductance of twigs outside the chambers and twigs which remained within the chambers for 23 weeks receiving ambient air.

scholarly journals Growing Conditions Influence Mite Damage on Apple and Peach Leaves

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 445-448 ◽  
Author(s):  
Richard J. Campbell ◽  
Kendrick N. Mobley ◽  
Richard P. Marini
Keyword(s):  
Regression Models ◽  
Spider Mite ◽  
Prunus Persica ◽  
Net Photosynthesis ◽  
Field Conditions ◽  
Panonychus Ulmi ◽  
Experiment Control ◽  
Mite Feeding ◽  
Growing Conditions ◽  
Leaf N Content

The effect of growing conditions on the physiological damage caused by mite feeding was evaluated. Control and twospotted spider mite (Tetranychus urticae Koch)-infested `Imperial Delicious' apple (Malus domestica Borkh.) and `Redhaven' peach [Prunus persica L. (Batsch.)] trees were grown under winter and summer greenhouse conditions. Mite feeding reduced net photosynthesis (Pn) of apple in both winter and summer, with equivalent regression models (Pn on mite days). Total chlorophyll content (TCHL) was decreased, and specific leaf weight (SLW) was increased by mite feeding in both winter and summer. In peach, Pn was also reduced by mite feeding, with equivalent regression models in winter and summer. SLW was unaffected, and TCHL was reduced by mite feeding in both seasons. Transpiration (Tr) of apple and peach was inconsistently affected by mites in winter and summer. In another experiment, control and European red mite (ERM) [Panonychus ulmi (Koch)]-infested `Red-chief Delicious' apple trees were grown in the summer under both greenhouse and field conditions. ERM feeding negatively affected Pn in both the greenhouse and the field, but reductions were less under field conditions. Mites reduced Tr 28% in the greenhouse and 12% in the field. TCHL, SLW, and leaf N content (LFN) were reduced by 16%, 24%, and 26%, respectively, in the greenhouse. In the field, TCHL was not significantly reduced, and SLW and LFN were reduced by 6% and 13%, respectively.

New Unified Analytical Model of Backscattering Coefficient From Low- to High-Field Conditions in Quasi-Ballistic Transport

2008 ◽  
Vol 29 (12) ◽  
pp. 1392-1394 ◽  
Author(s):  
SÉbastien Martinie ◽  
Daniela Munteanu ◽  
Gilles Le Carval ◽  
Jean-Luc Autran
Keyword(s):  
Analytical Model ◽  
High Field ◽  
Ballistic Transport ◽  
Field Conditions ◽  
Backscattering Coefficient

IMPROVING THE DEVELOPMENT OF COFFEA ARABICA AFTER CHANGING THE PATTERN OF LEAF GAS EXCHANGE BY WATERING CYCLES

2010 ◽  
Vol 46 (3) ◽  
pp. 381-391 ◽  
Author(s):  
PAULA NOVAES ◽  
JOÃO PAULO SOUZA ◽  
CARLOS HENRIQUE BRITTO ASSIS PRADO
Keyword(s):  
Gas Exchange ◽  
Coffea Arabica ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Area Ratio ◽  
Field Conditions ◽  
Initial Growth ◽  
Initial Development ◽  
Vegetative And Reproductive Growth ◽  
Flowering Intensity

SUMMARYHardening of Coffea arabica saplings by watering cycles (WCs) might be a suitable practice to achieve higher tolerance to low leaf water potential (Ψleaf) before transplanting to the field. As a consequence, hardening could promote growth and biomass gain during the initial development of C. arabica in the field. Thus, the less interrupted initial growth in a changing environment should confer higher flowering intensity in hardened than in control plants. The aim of this work was to verify if leaf gas exchange and Ψleaf behaviour of C. arabica saplings grafted on C. canephora showed consistent alterations during hardening by WCs and if this was effective to improve vegetative and reproductive growth under field conditions. For these reasons, saplings of the Mundo Novo cultivar of C. arabica grafted on C. canephora were submitted to seven WCs over 35 days. Each WC was completed when net photosynthesis was close to zero. The pattern of leaf gas exchange, mainly stomatal conductance (gs), was modified permanently after three WCs and the new pattern of leaf gas exchange could result in a more positive water balance and less interrupted development of C. arabica saplings in the field, particularly due to permanent low values of gs. After field transplantation, hardened plants showed greater height and stem diameter, more leaves and branches, and superior biomass production in leaves, stem and roots than control plants in dry and wet periods. The number of flowers was also significantly higher in hardened than in control plants. On the other hand, similar values were found between control and hardened plants in the leaf area ratio and the shoot/root ratio. Therefore, previous hardening by WCs was effective in improving leaf gas exchange, vegetative and reproductive development under field conditions and maintained the original biomass partitioning among the main plant compartments in dry and wet periods.

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