Net photosynthesis and stomatal conductance of red spruce twigs before and after twig detachment

1993 ◽  
Vol 23 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Fan-Rui Meng ◽  
Paul A. Arp
Keyword(s):  
Stomatal Conductance ◽  
Relative Humidity ◽  
New Brunswick ◽  
Photosynthetically Active Radiation ◽  
Regression Models ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Red Spruce ◽  
Active Radiation ◽  
Before And After

Rates of net photosynthesis and stomatal conductance of red spruce (Picearubens Sarg.) twigs were measured in field conditions before and after twig detachment on clear midsummer days in New Brunswick. Although these variables did not change significantly within about 6 min after twig detachment, they did drop continually after detachment. Regression models for the rates of net photosynthesis and stomatal conductance were developed that can be used to simulate this drop. Photosynthetically active radiation, leaf temperature, relative humidity, and CO2 concentration were the principal covariates in these models. The regressions improved by including simulated leaf moisture values in the analysis of data obtained after twig detachment.

Fumigating mature spruce branches with SO2: effects on net photosynthesis and stomatal conductance

1994 ◽  
Vol 24 (7) ◽  
pp. 1464-1471 ◽  
Author(s):  
Fan-Rui Meng ◽  
R.M. Cox ◽  
Paul A. Arp
Keyword(s):  
Stomatal Conductance ◽  
Regression Models ◽  
Late Summer ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Red Spruce ◽  
Direct Proportion ◽  
Active Radiation ◽  
Foliage Leaf ◽  
Leaf Yellowing

Branches on mature red spruce trees (Picearubens Sarg.) were fumigated with SO2 in late summer of 1990 and 1991. There were four SO2 treatment levels (0, 0.1, 0.2, and 0.4 ppm) and 12 fumigation chambers. Each treatment was replicated on three neighboring trees. Net photosynthesis and stomatal conductance of current-year foliage were determined with a Li-Cor photosynthesis system. Rates of foliar SO2 absorption were estimated using regression models, with leaf temperature, relative humidity, atmospheric CO2 concentrations, and photosynthetically active radiation as predictors. Fumigation effects became visible in terms of needle yellowing and browning after a few weeks of treatment. Effects on net photosynthesis and stomatal conductance were generally negative and in direct proportion with cumulative foliar SO2 absorption. It was found that, in shade-adapted foliage, visible symptoms were delayed, and stomatal conductance was slightly stimulated at low SO2 levels. In other foliage, leaf yellowing and browning occurred earlier, and stomatal conductance was depressed. Net photosynthesis was depressed at about the same rate regardless of branch position. Foliage subjected to high SO2 concentration treatments did not recover from SO2 damage 1 year after treatment: needles had fallen off the twigs, and needle and twig length of new foliage was reduced.

scholarly journals A Model for Net Photosynthesis of Rose Leaves as a Function of Photosynthetically Active Radiation, Leaf Temperature, and Leaf Age

1990 ◽  
Vol 115 (3) ◽  
pp. 486-491 ◽  
Author(s):  
J.H. Lieth ◽  
C.C. Pasian
Keyword(s):  
Photosynthetically Active Radiation ◽  
Mathematical Description ◽  
Leaf Age ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Rosa Hybrida ◽  
Crop Canopy ◽  
Active Radiation ◽  
The Relationship

A mathematical description for the relationship between the rate of rose (Rosa hybrida L.) leaf net photosynthesis and photosynthetically active radiation, leaf temperature, and leaf age is developed. The model provides a tool for the prediction of these rates for leaves growing in a rose crop canopy.

scholarly journals 357 PHOTOSYNTHETIC RESPONSE OF SELECT RED MAPLE CULTIVARS TO LIGHT INTENSITY

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 482b-482
Author(s):  
Jeff L. Sibley ◽  
D. Joseph Eakes ◽  
Charles H. Gilliam ◽  
William A. Dozier
Keyword(s):  
Stomatal Conductance ◽  
Light Intensity ◽  
Linear Relationship ◽  
Photosynthetically Active Radiation ◽  
Acer Rubrum ◽  
Net Photosynthesis ◽  
Photosynthetic Response ◽  
Red Maple ◽  
Active Radiation ◽  
Use Efficiency

Net photosynthesis (Pn), stomatal conductance (Cs), transpiration (Ts), and water use efficiency (WUE) were determined with a LICOR 6250 Portable Photosynthesis System for four cultivars of Acer rubrum L. under light intensities ranging from 300 to 1950 μmol·m-2·sec-1 photosynthetically active radiation (PAR). As PAR increased, there was a linear relationship for Pn, Cs, and Ts for the cultivars `Franksred' (Red Sunset TM) and `October Glory'. In contrast, the cultivars `Schlesingeri' and `Northwood' had quadratic relationships for Pn and Cs as PAR increased. Ts was quadratic for `Schlesingeri' and had a linear relationship for `Northwood.' WUE was quadratic for each of the four cultivars.

Formation of the photosynthetic indicators of spring wheat depending on the variety and pre-sowing treatment

10.12737/1361 ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. 96-100
Author(s):  
Воробьева ◽  
Tatyana Vorobeva ◽  
Шашкаров ◽  
Leonid Shashkarov
Keyword(s):  
Leaf Area ◽  
Spring Wheat ◽  
Photosynthetically Active Radiation ◽  
Seed Treatment ◽  
Net Photosynthesis ◽  
Coefficient Of Performance ◽  
Cropping Pattern ◽  
Efficiency Coefficient ◽  
Active Radiation ◽  
Photosynthetic Productivity

This article describes the formation of leaf area, photosynthetic capacity of crops, the net photosynthetic efficiency, leaves productivity and efficiency, Coefficient of performance (COP) of photosynthetically active radiation (PAR) of spring wheat, using Nano- Gro seed treatment instead of the traditional etching, depending on the varietal characteristics o dark gray forest soils of the Nizhniy Novgorod region. The study was carried out on varieties Margarita, Marusya and Sofia. In connection with this problem, above-mentioned issues are relevant to the present day. Rising the yields of spring wheat to the level of its genetically determined potential is only possible with an increase in photosynthetic productivity of crops, primarily due to the proper selection of varieties for specific soil-climatic zones. Cropping pattern should provide the absorption of at least 2% of PAR. The main absorbing body is a leaf. Therefore the need for a crop with optimum leaf surface area. The study revealed the following, the maximum leaf area of plants of spring wheat is formed in earing seed treatment by Nano-Gro. On average, during the growing season net photosynthesis productivity of Margarita variety was 4.5-5.7 g/m2, Maroussia - 4.6-4.8 g/m2 and Sofia - 3.8-5.2 g/m2. Maximum values of net photosynthetic productivity of crops are characterized by variations in seed treatment by Nano-Gro and Margarita variety. The highest efficiency (2.46, 2.57 and 2.55 kg by 1000 units) was observed on the leaves treated by Nano-Gro and the efficiency of Coefficient of performance (COP) of photosynthetically active radiation (PAR) is 1,54-1,81 %. Margarita and Marussia were characterized by maximum values of productivity of leaf and Coefficient of performance (COP) of photosynthetically active radiation (PAR).

The impact of kaolin clay sprays on leaf gas exchange of Ginger Gold apple trees in New Brunswick

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 1377-1381 ◽  
Author(s):  
J. P. Privé ◽  
L. Russell ◽  
A. LeBlanc
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
New Brunswick ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Apple Orchard ◽  
Kaolin Clay ◽  
Gas Exchange Parameters ◽  
Leaf Physiology ◽  
The Impact

A field trial was conducted over two growing seasons in a Ginger Gold apple orchard in Bouctouche, New Brunswick, Canada to examine the impact of Surround (95% kaolin clay) on leaf gas exchange [net photosynthesis (Pn), stomatal conductance (gs), intercellular CO2 (Ci) and transpiration (E)]. In 2004, a greater rate of Pn and gs was achieved at the higher than at the lower frequency of Surround applications. This was particularly notable at leaf temperatures exceeding 35°C. In 2005, no significant (P ≤ 0.05) differences among leaf residue groupings [Trace (< 0.5 g m-2), Low (0.5 to 2 g m-2), and High (≥ 2 g m-2)] were found for the four leaf gas exchange parameters at leaf temperatures ranging from 25 to 40°C. It would appear that under New Brunswick commercial orchard conditions, the application of Surround favours or has no effect on leaf gas exchange. Key words: Surround, particle film, leaf physiology, photosynthesis, stomatal conductance, intercellular CO2, transpiration

Gas exchange processes of yellow-cedar (Chamaecyparis nootkatensis) in response to environmental variables

1991 ◽  
Vol 69 (12) ◽  
pp. 2684-2691 ◽  
Author(s):  
Steven C. Grossnickle ◽  
John H. Russell
Keyword(s):  
Stomatal Conductance ◽  
Response Surface ◽  
Photosynthetically Active Radiation ◽  
Vapour Pressure ◽  
Vapour Pressure Deficit ◽  
Surface Model ◽  
Root Temperature ◽  
Active Radiation ◽  
Chamaecyparis Nootkatensis ◽  
Exchange Processes

Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) gas exchange processes were measured in response to the following primary environmental variables: photosynthetically active radiation, vapour pressure deficit, root temperature, and soil moisture. Under nonlimiting edaphic conditions, maximum stomatal conductance and maximum CO2 assimilation increased rapidly as photosynthetically active radiation increased from 0 to 200 μmol∙m−2∙s−1 and from 0 to 500 μmol∙m−2∙s−1, respectively. Thereafter, greater photosynthetically active radiation levels only resulted in minor increases in stomatal conductance and CO2 assimilation. Maximum stomatal conductance and maximum CO2 assimilation declined in a concave manner as vapour pressure deficit increased from 1 to 5 kPa. Response surface model for stomatal conductance showed vapour pressure deficit was the primary influence after light had caused initial stomatal opening. Response surface modeling approach showed CO2 assimilation increased as photosynthetically active radiation increased, but increased vapour pressure deficit resulted in a suppression of CO2 assimilation. Response surface model showed internal CO2 concentration declined sharply as photosynthetically active radiation increased from 0 to 500 μmol∙m−2∙s−1, but it remained constant with increasing vapour pressure deficit. Decreasing root temperature resulted in a continual decline in CO2 assimilation and stomatal conductance from 22 to 1 °C, while internal CO2 concentration declined from 22 to 13 °C with little change between 13 and 1 °C. As predawn shoot water potential decreased from −0.5 to −2.0 MPa, CO2 assimilation declined in a linear manner, while stomatal conductance and internal CO2 concentration declined in a concave manner. Key words: Chamaecyparis nootkatensis, CO2 assimilation, stomatal conductance, internal CO2 concentration, photosynthetically active radiation, vapour pressure deficit, root temperature, predawn shoot water potential.

scholarly journals Pepper Photosynthesis, Stomatal Conductance, Transpiration, and Water Use Efficiency Differ with Variety, Indigenous Habitat, and Species of Origin

HortScience ◽  
2019 ◽  
Vol 54 (10) ◽  
pp. 1662-1666
Author(s):  
John Erwin ◽  
Tanveer Hussein ◽  
David J. Baumler
Keyword(s):  
Stomatal Conductance ◽  
Relative Humidity ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Temperature ◽  
Greenhouse Production ◽  
Hot Peppers ◽  
Use Efficiency ◽  
Dry Climates ◽  
Tropical Climates

The instantaneous photosynthetic rate (Pn), transpiration rate (E), and stomatal conductance (gS) were measured for 33 outdoor-grown Capsicum varieties (varying in species of origin and indigenous habitat) between 29 July and 22 Aug. 2017 using a portable gas exchange meter. Cuvette leaf temperature (Tleaf) and relative humidity (RH) were recorded at that same time. Pn differed from 3.6 to 3.7 for ‘Malawi Piquante’ and ‘Korean Long Green’ peppers to 16.3 μmol CO2/m2/s (fixed) for ‘Thai Hot’ peppers. The gS differed from 0.01 to 0.05 among 13 varieties to 0.28 mmol H2O/m2/s for ‘Thai Hot’ peppers. E differed from 0.43 to 0.59 among three varieties to 4.14 to 4.20 mmol H2O/m2/s for ‘CGN 22091’ and ‘Peruvian Purple’ peppers. Water use efficiency (WUE; Pn/E) varied from 2.92 to 3.43 among three varieties to 5.10 to 7.20 for 16 other varieties. C. annuum derived varieties had higher Pn (9.4 μmol CO2/m2/s fixed) than varieties derived from other species (4.5–8.6 μmol CO2/m2/s fixed). Varieties originating from dry climates had higher Pn (12.5 μmol CO2/m2/s fixed) than those originating from temperate or tropical climates (8.0–8.8 μmol CO2/m2/s fixed). Tleaf (27 to 33 °C) and RH (38% to 39% and 57% to 59%) differed among varieties. Pn was positively correlated with gS, E, and RH and was negatively correlated with WUE. We found that Capsicum Pn, E, and gS varied more than has been previously reported, and our data suggested that Pn, gS, and E data of outdoor-grown peppers should be used only when selecting parents for a breeding program (unless progeny is intended for greenhouse production).

scholarly journals Simulated Transport, Postproduction Irradiance Influence Postproduction Performance of Potted Roses

HortScience ◽  
1991 ◽  
Vol 26 (11) ◽  
pp. 1401-1404 ◽  
Author(s):  
Terril A. Nell ◽  
Cor Vonk Noordegraaf
Keyword(s):  
Relative Humidity ◽  
Photosynthetically Active Radiation ◽  
Active Radiation ◽  
Irradiance Level ◽  
Fluorescent Lamps ◽  
Level 1

Three simulated transport temperatures (5, 11, or 17C) and durations. (3, 6, or 9 days) were used to evaluate the postproduction flowering patterns of miniature potted rose (Rosa sp) `Orange Rosamini'. The postproduction environment was maintained at 20 ± lC, 60% ± 5% relative humidity (RI-I), and an irradiance level, from cool-white fluorescent lamps, of 4.5 W·m-2 photosynthetically active radiation (PAR) for 12 hours daily to simulate conditions at the retail or consumer level. At 3 weeks postproduction, plants held for 9 days at 17C had the fewest buds showing color per plant. As temperature increased, there were fewer flowers per plant at weeks 2 and 3 of postproduction. In a second study, the effect of simulated transport (3 days at 5C vs. no transport) and postproduction irradiance level (1, 2, or 4 W·m-2 PAR) were evaluated over a 7-week postproduction period for `Orange Rosamini'. A three-way interaction was observed between simulated transport treatment, postproduction irradiance level, and time in postproduction for the number of open flowers per plant. Plants responded similarly at 1 and 2 W·m2 throughout the postproduction period, regardless of transport treatment; however, at 4 W·m-2 the plants of the no transport treatment had two to three open flowers each week up to week 6 of postproduction, while plants subjected to simulated transport followed the pattern of one and two open flowers for 0 to 3 weeks. Flowering then increased to three to four open flowers for the duration of the postproduction period. A third study involved two simulated transport treatments (3 days at SC vs. no transport), three postproduction irradiance levels (1, 2, and 4 W·m-2 PAR), and six miniature rose cultivars (`Orange Rosamini', `Red Minimo' `Sweet Rosamini', `Golden Rosamini', `Favorite Rosamini', and `White Rosamini'). Plants held at 1 or 2 W·m-2 for 3 weeks had no open flowers, while those held at 4 W·m-2 for 3 weeks had one to four open flowers, except `Sweet Rosamini', which had no open flowers with simulated transport.

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