Effect of Interspecific Interference, Light Intensity, and Soil Moisture on Soybean (Glycine max), Common Cocklebur (Xanthium strumarium), and Sicklepod (Cassia obtusifolia) Water Uptake

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 534-540 ◽  
Author(s):  
Ronald E. Jones ◽  
Robert H. Walker
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Leaf Area ◽  
Water Uptake ◽  
Root Weight ◽  
Pressure Potential ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Shoot Weight ◽  
The Relationship

Greenhouse and growth chamber experiments with potted plants were conducted to determine the effects of interspecific root and canopy interference, light intensity, and soil moisture on water uptake and biomass of soybean, common cocklebur, and sicklepod. Canopy interference and canopy plus root interference of soybean with common cocklebur increased soybean water uptake per plant and per unit leaf area. Root interference with soybean decreased common cocklebur water uptake per plant. Canopy interference of soybean with sicklepod increased soybean water uptake per unit leaf area, while root interference decreased uptake per plant. Combined root and canopy interference with soybean decreased water uptake per plant for sicklepod. Soybean leaf area and shoot weight were reduced by root interference with both weeds. Common cocklebur and sicklepod leaf area and shoot weight were reduced by root and canopy interference with soybeans. Only common cocklebur root weight decreased when canopies interfered and roots did not. The relationship between light intensity and water uptake per unit leaf area was linear in both years with water uptake proportional to light intensity. In 1991 water uptake response to tight was greater for common cocklebur than for sicklepod. The relationship between soil moisture level and water uptake was logarithmic. Common cocklebur water uptake was two times that of soybean or sicklepod at −2 kPa of pressure potential. In 1991 common cocklebur water uptake decreased at a greater rate than soybean or sicklepod in response to pressure potential changes from −2 to −100 kPa.

Carbon Isotope Discrimination and Gas Exchange in Coffea arabica During Adjustment to Different Soil Moisture Regimes

1992 ◽  
Vol 19 (2) ◽  
pp. 171 ◽  
Author(s):  
FC Meinzer ◽  
NZ Saliendra ◽  
C Crisosto
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Leaf Area ◽  
Coffea Arabica ◽  
Carbon Isotope Discrimination ◽  
Total Leaf Area ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Moisture Regimes ◽  
Area Basis

Although carbon isotope discrimination (Δ) has been reported to decline in plants growing under reduced soil moisture, there is little information available concerning the dynamics of adjustments in Δ and gas exchange following a change in soil water availability. In this study Δ, photosynthetic gas exchange, and growth were monitored in container-grown coffee (Coffea arabica L.) plants for 120 days under three soil moisture regimes. At the end of 120 d, total leaf area of plants irrigated twice weekly was one half that of plants irrigated twice daily, although their assimilation rates on a unit leaf area basis were nearly equal throughout the experiment. This suggested that maintenance of nearly constant photosynthetic characteristics on a unit leaf area basis through maintenance of a smaller total leaf area may constitute a major mode of adjustment to reduced soil moisture availability in coffee. Intrinsic water-use efficiency (WUE) predicted from foliar Δ values was highest in plants irrigated weekly, intermediate in plants irrigated twice weekly and lowest in plants irrigated twice daily. When instantaneous WUE was estimated from independent measurements of total transpiration per plant and assimilation on a unit leaf area basis, the reverse ranking was obtained. The lack of correspondence between intrinsic and instantaneous WUE was attributed to adjustments in canopy morphology and leaf size in the plants grown under reduced water supply which enhanced transpiration relative to assimilation. Values of Δ predicted from the ratio of intercellular to ambient CO2 partial pressure determined during gas exchange measurements were not always consistent with measured foliar Δ. This may have resulted from a patchy distribution of stomatal apertures in plants irrigated weekly and from a lag period between adjustment in gas exchange and subsequent alteration in Δ of expanding leaves. The importance of considering temporal and spatial scales, and previous growth and environmental histories in comparing current single leaf gas exchange behaviour with foliar Δ values is discussed.

Correlations Between Carbon Isotope Discrimination and Climate of Native Habitats for Diverse Eucalypt Taxa Growing in a Common Garden

1996 ◽  
Vol 23 (3) ◽  
pp. 311 ◽  
Author(s):  
JE Anderson ◽  
J Williams ◽  
PE Kriedemann ◽  
MP Austin ◽  
GD Farquhar
Keyword(s):  
Soil Moisture ◽  
Leaf Area ◽  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Common Garden ◽  
Potential Evaporation ◽  
Unit Leaf Area ◽  
Isotope Discrimination ◽  
Unit Leaf ◽  
Native Habitats

Distributions of common species of Eucalyptus in south-eastem Australia are related to gradients in temperature and rainfall. To determine whether intrinsic water-use efficiency (as indexed by carbon isotope discrimination, Δ) or other leaf attributes were related to climate of native habitats, we sampled 17 populations representing 14 species of Eucalyptus growing in a common garden in south- central New South Wales. Phreatophytes were clearly distinguished from populations that are totally dependent upon soil moisture derived from rainfall by having higher Δ at a particular level of rainfall. Among 12 non-phreatophytic populations (11 species), Δ was positively correlated with mean annual precipitation (r = 0.75, P = 0.005), December-March precipitation (r = 0.79, P = 0.002), an index of annual soil moisture (r = 0.81, P = 0.001) and seasonality of precipitation (r = 0.85, P < 0.001). There were similarly strong but negative correlations between Δ and potential evaporation during the summer months, but Δ was not correlated with annual potential evaporation of the source sites. Leaf mass per unit area (ρe) was negatively correlated with indices of water availability, positively correlated with nitrogen per unit leaf area (r = 0.90, P < 0.001), and negatively correlated with Δ (r = -0.73, P = 0.007). A was negatively correlated with area-based leaf nitrogen (r = -0.79, P = 0.002). These complementary correlations among Δ, ρe, and nitrogen per unit leaf area indicate that variation in Δ may stem largely from variation in photosynthetic capacity. The results provide strong evidence that variation in Δ and ρe reflect genetic adaptations to native habitats.

Stomatal Development During Leaf Expansion in Tobacco and Sunflower

1975 ◽  
Vol 23 (2) ◽  
pp. 253 ◽  
Author(s):  
HM Rawson ◽  
CL Craven
Keyword(s):  
Leaf Area ◽  
Stomatal Density ◽  
Stomatal Development ◽  
Developmental Patterns ◽  
Full Size ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Wide Range ◽  
Young Leaves ◽  
Different Levels

Changes in stomatal density and size were followed in tobacco and sunflower leaves expanding from 10% of final area (10% Amax) to Amax under different levels of radiation. Lower radiation increased final leaf area, reduced stomatal densities, and increased area per stoma but had little effect on stomatal area per unit leaf area at Amax. In very young leaves (20% Amax) there was a wide range in the sizes of individual stomata, some stomata being close to full size, but by Amax differences were small. The possible relationship between the developmental patterns described and photosynthesis is briefly discussed.

Photosynthetic Acclimation of Alocasia macrorrhiza (L.) G. Don

1988 ◽  
Vol 15 (2) ◽  
pp. 107 ◽  
Author(s):  
WS Chow ◽  
L Qian ◽  
DJ Goodchild ◽  
JM Anderson
Keyword(s):  
Charge Density ◽  
Leaf Area ◽  
Cell Walls ◽  
Surface Charge Density ◽  
Leaf Tissue ◽  
O2 Evolution ◽  
Palisade Cell ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Growth Irradiance

The photosynthetic acclimation of Alocasia macrorrhiza (L.) G. Don, a species naturally occurring in deep shade in rainforests, has been studied in relation to a wide range of controlled irradiances during growth (~3-780 �mol photons m-2 s-1 of fluorescent or incandescent light, 10 h light/ 14 h dark). At the maximum growth irradiances, the light- and CO2-saturated rates of O2 evolution per unit leaf area were ~4 times as high as at low irradiance, and approached those of glasshouse-grown spinach. Growth at maximum irradiances reduced the quantum yield of O2 evolution only slightly. Changes in the anatomy of leaf tissue, the ultrastructure of chloroplasts and the composition of chloroplast components accompanied the changes in photosynthetic functional characteristics. At low growth irradiance, palisade cell chloroplasts were preferentially located adjacent to the distal periclinal cell walls and had large granal stacks, and the destacked thylakoids had a very low surface charge density. In contrast, at higher growth irradiance, palisade cell chloroplasts were preferentially located adjacent to the anticlinal cell walls; they had small granal stacks, large stromal space, and a high surface charge density on the destacked thylakoids. The number of chloroplasts per unit section length increased with growth irradiance. Ribulosebisphosphate carboxylase activity per unit leaf area increased markedly with irradiance. Photosystem II, cytochrome f and latent ATPase activity per unit chlorophyll increased to a lesser extent. While the chlorophyll a/chlorophyll b ratio increased substantially with growth irradiance, the chlorophyll content per unit leaf area declined slightly. Our results show that coordinated changes in the structure of leaf tissue, and the organisation and composition of chloroplast components are responsible for Alocasia being capable of acclimation to high as well as low irradiance.

scholarly journals Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 843-846 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yoshiaki Kitaya ◽  
Saki Hayashi
Keyword(s):  
Leaf Area ◽  
Growth Parameters ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Unit Leaf Area ◽  
Cucumber Seedlings ◽  
Unit Leaf ◽  
Net Assimilation ◽  
Normal Light

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.

scholarly journals Nitrogen, Phosphorus, and Potassium Nutrition Increases Growth and Total Polyphenol Concentrations of Bush Tea in a Shaded Nursery Environment

2007 ◽  
Vol 17 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Fhatuwani N. Mudau ◽  
Puffy Soundy ◽  
Elsa S. du Toit
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Block Design ◽  
Limpopo Province ◽  
Root Weight ◽  
Total Polyphenol ◽  
Phosphorus And Potassium ◽  
Shoot Weight ◽  
Number Of Branches ◽  
Leaf N

The objective of this investigation was to determine the effects of simultaneous applications of nitrogen (N), phosphorus (P), and potassium (K) nutrition on growth and chemical analysis of bush tea (Athrixia phylicoides). Four consecutive trials were conducted at Morgenzon (Louis Trichardt, Limpopo Province, South Africa), a commercial nursery, one at each season (autumn, winter, spring, and summer) under 50% shade. Treatments comprised three levels of N (300, 350, 400 kg·ha−1), three levels of P (250, 300, 350 kg·ha−1), and three levels K (150, 200, 250 kg·ha−1). The experimental design was a 3 × 3 × 3 factorial experiment arranged in a randomized complete-block design with four replications. Parameters recorded were plant height, number of branches and leaves, fresh and dry stem weight, fresh and dry root weight, stem girth, fresh and dry shoot weight, leaf area, and percent concentration of leaf and root tissue N, P, K, and total polyphenol concentrations as influenced by season in a shaded nursery environment. Treatment combinations of N and P at rates of 300 kg·ha−1 and K at 200 kg·ha−1 increased fresh and dry shoot weight, number of leaves, leaf area, and concentration of total polyphenols. Other treatments did not consistently affect concentrations of leaf N, P, or K during the study period, although the treatment that received combinations of N and P at rates of 300 kg·ha−1 and K at 200 kg·ha−1 always had the highest concentrations of leaf N, P, and K and lowest root N, P, and K concentrations. No differences in plant height, number of branches, number of flower buds (autumn and winter), stem girth, fresh and dry root weight, and fresh and dry stem weight due to treatment combinations were observed.

A Measurement of the Total Mass of Spray and Irrigation Mixtures Intercepted by Small Whole Plants

1997 ◽  
Vol 11 (3) ◽  
pp. 466-472 ◽  
Author(s):  
R. D. Wauchope ◽  
H. R. Sumner ◽  
C. C. Dowler
Keyword(s):  
Leaf Area ◽  
Total Mass ◽  
Spray Deposition ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Cotton Plants ◽  
Before And After ◽  
Corn Plants ◽  
Whole Plants

A plant-weighing procedure was used to measure the total mass of spray mixture intercepted by small whole corn and cotton plants. Mixtures of water and water plus crop oil concentrate or spreader–sticker were applied at spray volumes of 280 to 28,000 L/ha. The plants were weighed before and after passing under the spray and leaf areas, and shoot fresh and dry weights for each plant were measured. Spray deposition increased with spray volumes but not proportionally. Corn plants were larger than cotton plants and retained more spray per plant; however, cotton retained more spray per unit leaf area. The two adjuvants had similar effects on deposition, tending to increase it in corn and decrease it in cotton.

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