Field measurements of the photosynthetic rate of potatoes grown with different amounts of nitrogen fertilizer

1988 ◽  
Vol 111 (1) ◽  
pp. 85-90 ◽  
Author(s):  
D. M. Firman ◽  
E. J. Allen
Keyword(s):  
Photosynthetic Rate ◽  
Nitrogen Fertilizer ◽  
Leaf Age ◽  
Field Measurements ◽  
N Fertilizer ◽  
Photosynthetic Rates ◽  
Rate Of Photosynthesis ◽  
Applied Nitrogen

SummaryThree experiments are reported in which the photosynthetic rates of potatoes grown with various amounts of applied nitrogen (N) fertilizer were measured. Rates of photosynthesis in leaves of plants grown without applied N reached levels as high as those receiving N in all experiments. The rate of photosynthesis in the uppermost leaves of the variety Pentland Crown was found to increase during the season, whereas in Estima rates remained the same. Decline in the rate of photosynthesis with leaf age was more rapid in strongly shaded leaves than in less shaded leaves which were found to be photosynthetically active 8 weeks after expansion.

Effects of foliar applied nitrogen fertilizer on cotton waterlogged in a cracking grey clay

1987 ◽  
Vol 38 (4) ◽  
pp. 681 ◽  
Author(s):  
AS Hodgson ◽  
DA MacLeod
Keyword(s):  
Nitrogen Fertilizer ◽  
Furrow Irrigation ◽  
N Fertilizer ◽  
Control Treatment ◽  
Yield Response ◽  
The Third ◽  
Foliar N ◽  
Waterlogging Treatment ◽  
Applied Nitrogen

Foliar-applied nitrogen (N) fertilizer was investigated as a means of ameliorating the damage to cotton of waterlogging associated with extended furrow irrigation of a cracking grey clay. Dissolved urea was applied at 0, 5, 10 and 20 kg N ha-1 to the cotton foliage one day before furrow irrigations lasting 4, 8, 16 and 32 h. Treatments were repeated at three crop irrigations. Storms following the first two irrigations delayed the recovery from waterlogging and reduced treatment differences. However, foliar-applied N significantly increased late square and green boll numbers after the third irrigation, and produced more open bolls and heavier lint yields than the control treatment at harvest. Lint yields increased by 2.8, 5.9, 8.4 and up to 10.5 kg ha-1 per kg of foliar N applied before irrigations lasting 4, 8, 16 and 32 h, respectively. From this interaction it was concluded that foliar-applied N ameliorated the effects of waterlogging. Nevertheless, in the most severe waterlogging treatment, yield response to foliar N reached a limit, indicating that some other factor had become limiting.

Effects of leaf age, elevation and light conditions on photosynthesis and leaf traits in saplings of two evergreen conifers, Abies veitchii and A. mariesii

2020 ◽  
Vol 13 (4) ◽  
pp. 460-469
Author(s):  
Rina Suzuki ◽  
Koichi Takahashi
Keyword(s):  
Photosynthetic Rate ◽  
Leaf Age ◽  
Leaf Traits ◽  
Light Conditions ◽  
Coniferous Species ◽  
Photosynthetic Rates ◽  
Abies Veitchii ◽  
Maximum Photosynthetic Rate ◽  
Wide Range ◽  
High Elevations

Abstract Aims Subalpine coniferous species are distributed over a wide range of elevations in which they must contend with stressful conditions, such as high elevations and extended periods of darkness. Two evergreen coniferous species, Abies veitchii and Abies mariesii, dominate at low and high elevations, respectively, in the subalpine zone, central Japan. The aim of this study is to examine the effects of leaf age, elevation and light conditions on photosynthetic rates through changes in morphological and physiological leaf traits in the two species. Methods We here examined effects of leaf age, elevation and light conditions on photosynthesis, and leaf traits in A. veitchii and A. mariesii. Saplings of the two conifers were sampled in the understory and canopy gaps at their lower (1600 m) and upper (2300 m) distribution limits. Important Findings The two species showed similar responses to leaf age and different responses to elevation and light conditions in photosynthesis and leaf traits. The maximum photosynthetic rate of A. veitchii is correlated negatively with leaf mass per area (LMA) and non-structural carbohydrate (NSC) concentration. LMA increased at high elevations in the two species, whereas NSC concentrations increased only in A. veitchii. Therefore, the maximum photosynthetic rate of A. veitchii decreased at high elevations. Furthermore, maximum photosynthetic rates correlate positively with nitrogen concentration in both species. In the understory, leaf nitrogen concentrations decreased and increased in A. veitchii and A. mariesii, respectively. LMA decreased and the chlorophyll-to-nitrogen ratio increased in understory conditions only for A. mariesii, suggesting it has a higher light-capture efficiency in dark conditions than does A. veitchii. This study concluded that A. mariesii has more shade-tolerant photosynthetic and leaf traits and its photosynthetic rate is less affected by elevation compared with A. veitchii, allowing A. mariesii to survive in the understory and to dominate at high elevations.

The influence of red and blue light on the rate of photosynthesis and the CO2 compensation point at various oxygen concentrations

1970 ◽  
Vol 48 (6) ◽  
pp. 1251-1257 ◽  
Author(s):  
N. P. Voskresenskaya ◽  
G. S. Grishina ◽  
S. N. Chmora ◽  
N. M. Poyarkova
Keyword(s):  
Nicotiana Tabacum ◽  
Blue Light ◽  
Photosynthetic Rate ◽  
Prolonged Exposure ◽  
Red Light ◽  
Compensation Point ◽  
Gas Analyzer ◽  
Co2 Compensation Point ◽  
Rate Of Photosynthesis ◽  
Light Inhibition

Apparent photosynthesis of attached leaves of Phaseolus vulgaris, Vicia faba, Pisum sativum, and Nicotiana tabacum at various intensities of blue and red light was measured by infrared CO2 gas analyzer in a closed system. Simultaneously the CO2 compensation point was measured.It was found that light-limited photosynthetic rate in blue light was equal to or more than that in red light. Inhibition of photosynthesis, which sometimes occurred at light-saturated intensities of blue light, could be avoided by addition of red light, prolonged exposure of the plants to blue light, or by lowering the O2 concentration. Accordingly, the increase of photosynthetic rate due to change of O2 concentration from 21 to 3% O2 is higher in blue light only when photosynthesis is inhibited by blue light at 21% O2. The data on the action of blue and red light on the CO2 compensation point seems to exclude the activation of photorespiration by blue light.The possible effects of blue light on apparent photosynthesis are discussed on the basis of the results presented.

Effects of Clone and Irrigation on the Stomatal Conductance and Photosynthetic Rate of Tea (Camellia sinensis)

1994 ◽  
Vol 30 (1) ◽  
pp. 1-16 ◽  
Author(s):  
B. Gail Smith ◽  
Paul J. Burgess ◽  
M. K. V. Carr
Keyword(s):  
Stomatal Conductance ◽  
Camellia Sinensis ◽  
Photosynthetic Rate ◽  
Leaf Temperature ◽  
Temperature Optimum ◽  
Photosynthetic Rates ◽  
Clone Selection ◽  
Treatment Interaction ◽  
Dry Seasons ◽  
The Relationship

SummaryStomatal conductances (g) and photosynthetic rates (A) were monitored in six tea clones planted in a clone X irrigation experiment in the Southern Highlands of Tanzania. Measurements were made during the warm dry seasons of 1989 and 1990. There was no genotype X treatment interaction in the response in A or g of the various clones to irrigation. Irrigation increased A more than it increased g. Irrigation also increased the temperature optimum for photosynthesis and decreased photo-inhibition at high illuminance. Clones differed in g and A, and in the relationship between leaf temperature and A. The implications of these findings for clone selection are discussed.

scholarly journals The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants

2011 ◽  
pp. 117-123
Author(s):  
Jaroslav Pokorny ◽  
Josef Pulkrábek ◽  
Karel Krofta ◽  
Josef Ježek
Keyword(s):  
Photosynthetic Rate ◽  
Copper Content ◽  
Copper Fungicides ◽  
Before And After ◽  
Elemental Copper ◽  
Rate Of Photosynthesis ◽  
Accredited Laboratory ◽  
Effect Of Copper ◽  
Copper Fungicide ◽  
Infrared Analyzer

The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.

Milk production from cows grazing on tropical grass pastures. 1. Effects of stocking rate and level of nitrogen fertilizer on the pasture and diet

1985 ◽  
Vol 25 (3) ◽  
pp. 505 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
RK Shepherd ◽  
P Martin
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Fertilizer Application ◽  
Stocking Rate ◽  
Crude Protein Content ◽  
Stocking Rates ◽  
Applied Nitrogen

A 3-year experiment was conducted at Kairi Research Station on the Atherton Tablelands, Queensland, to determine the effects of stocking rate and applied nitrogen fertilizer on the pasture yield and composition, diet selection by cows, and soil fertility of Gatton panic (Panicum maximum cv. Gatton) pastures. Thirty-two Friesian cows were used in a 4x2 factorial design: four stocking rates (2.0, 2.5, 3.0 and 3.5 cows/ha), each at two rates of fertilizer application 200 and 400 kg N/ha.year. The higher rate of fertilization increased the pasture green dry matter on offer at all samplings (P < 0.01); the increase ranged from 1 106 kg/ha in summer to 548 kg/ha in spring. Green dry matter decreased ( P< 0.0 1) with increasing stocking rate, with mean yields of 3736 and 2384 kg/ha at 2.0 and 3.5 cows/ha, respectively. Weed yields increased over the 3 years at the higher stocking rates for pastures receiving 200 kg N/ha.year. The crude protein content of leaf and stem increased with increasing stocking rate and amount of applied nitrogen fertilizer. Values ranged from 12.1 to 26.5% of dry matter (DM) in leaf and from 3.7 to 13.8% DM in stem. In leaf, sodium concentration (range 0.05-0.20% DM) was increased, while phosphorus concentration (range 0.21-0.44% DM) was decreased by the higher rate of fertilizer application. Plant sodium and phosphorus levels were inadequate for high levels of milk production. Dietary leaf content and crude protein contents were consistently increased by both a reduced stocking rate, and the higher rate of fertilization. Cows were able to select for leaf and at the lowest stocking rate, leaf in the diet averaged 38%; while the leaf content of the pasture was 20%. Dietary leaf content ranged from 38 to 57% in summer and from 11 to 36% in winter. Dietary crude protein ranged from 13 to 15% in summer and from 7 to 11% in winter and was positively correlated with pasture crude protein content and dietary leaf percentage. Soil pH decreased (P<0.05) from an overall mean of 6.3 in 1976 to 6.1 at 200 N and 5.8 at 400 N in 1979. Soil phosphorus status remained stable, while calcium and magnesium levels were lower (P<0.01) after 3 years.

Effects of supplementary nitrogen fertilizer on nodulation, yield and seed characteristics of soybean (Glycine max) on the Darling Downs

1975 ◽  
Vol 15 (76) ◽  
pp. 694 ◽  
Author(s):  
AJP Williamson ◽  
A Diatloff
Keyword(s):  
Glycine Max ◽  
Nitrogen Content ◽  
High Temperatures ◽  
Nitrogen Fertilizer ◽  
Rhizobium Japonicum ◽  
Research Station ◽  
Climatic Data ◽  
Depressive Effect ◽  
Four Seasons ◽  
Applied Nitrogen

In field experiments with soybeans (Glycine max) conducted over four seasons at Hermitage Research Station, Queensland, levels of applied nitrogen (as urea) up to 134 kg ha -1 were examined. Nodulated soybeans failed to respond to applied nitrogen in three out of the four seasons. A response was obtained in one season when abnormal climatic conditions of low rainfall and high temperatures resulted in a comparatively lower level of nodulation. The probability of such a response is discussed in relation to climatic data of the area over the past 108 years. Nodulation and nitrogen fertilizer increased seed size and nitrogen content of the seed in soils free of Rhizobium japonicum but nitrogen fertilizer had little effect on these characteristics in soils carrying R. japonicum. Oil content of the seed was negatively correlated with the nitrogen content in rhizobia-free soils. Nitrogen fertilizer had a depressive effect on nodulation. This effect was severe when inoculated soybeans were grown in soil free of R. japonicum particularly under conditions of declining soil moisture and high temperatures. In soils with R. japonicum the depressive effect was comparatively light.

Cellular Photosynthetic Rate of Fully and Partially Pigmented Chlamydomonas reinhardtii as a Function of Irradiance

2011 ◽  
Author(s):  
Thomas E. Murphy ◽  
Halil Berberog˘lu
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Algae ◽  
Photosynthetic Rate ◽  
Wild Strain ◽  
Experimental Setup ◽  
Light Penetration ◽  
Photosynthetic Rates ◽  
Planktonic Algae ◽  
Mass Cultures ◽  
Increase Productivity

This paper reports the cellular photosynthetic rates of the green algae Chlamydomonas reinhardtii wild strain and its truncated chlorophyll antenna transformant, tla1, as a function of local irradiance. It is hypothesized that reduction in the pigmentation of algae cells can enhance light peneration in mass cultures and increase productivity. Thus, an experimental setup was designed to expose each cell within planktonic algae cultures to a nearly uniform irradiance. An oxygen microsensor was used to monitor the photosynthetic rate as the irradiance onto the sample was varied. The results showed that the cellular photosynthetic rate of the wild strain, CC125, was greater than that of tla1 at all irradiances, by a factor that ranged from 1.7 to 4. Photoinhibition was observed in both strains, although the effect was more pronounced in CC125. Although less pigmented cells enable deeper light penetration in photobioreactors, their reduced phosotynthetic rate can negate this benefit.

THE RELATIONSHIP BETWEEN CHLOROPHYLL CONTENT AND RATE OF PHOTOSYNTHESIS IN SOYBEANS

1977 ◽  
Vol 57 (1) ◽  
pp. 1-5 ◽  
Author(s):  
B. R. BUTTERY ◽  
R. I. BUZZELL
Keyword(s):  
Linear Regression ◽  
Chlorophyll Content ◽  
Photosynthetic Rate ◽  
Regression Line ◽  
Quadratic Equation ◽  
Chlorophyll Contents ◽  
Rate Of Photosynthesis ◽  
Highly Correlated ◽  
The Relationship ◽  
Selection Of

Photosynthetic rate of soybeans (on a leaf area basis, PA) estimated from the incorporation of 14CO2 under field conditions was highly correlated with chlorophyll content of the side leaflets of the same leaves. Among a collection of 48 cultivars, the linear regression of PA on chlorophyll content accounted for 44% of the variation, whereas with a selection of genotypes with various mutant chlorophyll genes, the regression accounted for 81%. When the data for the two tests were re-calculated relative to the check cv. Altona, a quadratic equation between PA and chlorophyll accounted for nearly 90% of the variation. When photosynthetic rate was expressed on a unit chlorophyll basis (Pc), no significant differences among lines were established in the cultivar test. In the mutants test, significant differences in Pc were established with higher values of Pc associated with lower chlorophyll contents; a linear regression accounted for 45% of the variation. Transformation of the data from both experiments relative to Altona allowed the fitting of a common regression line (quadratic) which accounted for 63% of the variation. We suggest that initial screening of progenies in a breeding program for high photosynthetic rate could be done by measuring chlorophyll content.

EFFECT OF TYPE, RATE AND INCORPORATION OF LIME AND OF NITROGEN FERTILIZER AND GYPSUM ON MOVEMENT OF LIME IN SOIL COLUMNS

1986 ◽  
Vol 66 (4) ◽  
pp. 757-762
Author(s):  
P. B. HOYT ◽  
B. G. DROUGHT ◽  
G. H. NEILSEN ◽  
E. HOGUE
Keyword(s):  
Key Words ◽  
Soil Ph ◽  
Nitrogen Fertilizer ◽  
Soil Surface ◽  
Deionized Water ◽  
N Fertilizer ◽  
Soil Columns ◽  
Downward Movement ◽  
Type Rate

Soil columns were used to study downward movement of calcite and dolomite applied at two rates on the soil surface or incorporated 0–5 cm deep in combinations with gypsum and surface-applied N fertilizer. The columns were irrigated with 800 mm of deionized water applied over 3 wk. Incorporation of the liming materials greatly accelerated their downward movement in soil. Calcite and dolomite were equally effective in raising soil pH at the lower depths. Neither gypsum nor fertilizer nor doubling the liming rate had much effect on lime movement. Key words: Lime movement, calcite, dolomite, gypsum

Sign in / Sign up

Export Citation Format

Share Document