scholarly journals Physiological responses of two tropical weeds to shade: I. Growth and biomass allocation

1999 ◽  
Vol 34 (6) ◽  
pp. 944-952 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Leaf Area ◽  
Weed Management ◽  
Dry Mass ◽  
High Light ◽  
Low Light ◽  
Light Regimes ◽  
Leaf Dry Mass ◽  
Lower Ability ◽  
Total Plant ◽  
Plant Dry Mass

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.

scholarly journals Dissecting the Genotypic Variation of Growth Responses to Far-Red Radiation in Tomato

2021 ◽  
Vol 11 ◽  
Author(s):  
Yongran Ji ◽  
Theoharis Ouzounis ◽  
Henk J. Schouten ◽  
Richard G. F. Visser ◽  
Leo F. M. Marcelis ◽  
...  
Keyword(s):  
Leaf Area ◽  
Genotypic Variation ◽  
Dry Mass ◽  
Growth Responses ◽  
Light Emitting ◽  
Red Led ◽  
Total Plant ◽  
Net Assimilation ◽  
Tomato Genotypes ◽  
Plant Dry Mass

The recent development of light-emitting diodes (LEDs) and their application in modern horticulture stimulated studies demonstrating that additional far-red (FR) radiation (700–800 nm) increases plant dry mass. This effect of FR has been explained by improved photosynthesis and/or plant architecture. However, the genotypic variation in this response is largely unknown. Here, we aim to explore and explain the genotypic variation in growth responses to additional FR. We expected the genotypic variation in the responses of plant dry mass to additional FR. Further, we hypothesized that a significant improvement of both net assimilation rate (NAR) and leaf area ratio (LAR) is responsible for a strong dry mass increase under additional FR, while some genotypes respond only marginally or even negatively in NAR or LAR under FR, thus resulting in a weak FR effect on plant dry mass. To test these hypotheses, we grew 33 different tomato genotypes for 21 days with 0, 25, or 100 μmol m–2 s–1 of FR added to a common white + red LED background lighting of 150 μmol m–2 s–1. Genotypes responded similarly with respect to plant height, stem dry mass, and shoot:root ratio; i.e., they all increased with increasing FR. However, the response of total plant dry mass varied among genotypes. We categorized the genotypes into three groups (strongly, moderately, and weakly responding groups) based on their relative response in total plant dry mass to FR. Growth component analysis revealed that the strongly responding genotypes increased strongly in NAR rather than LAR. The weakly responding genotypes, however, showed a substantial increase in LAR but not NAR. The increase in LAR was due to the increase in specific leaf area. Leaf mass fraction, which is the other component of LAR, decreased with FR and did not differ between groups. In conclusion, tomato genotypes that increased strongly in NAR in response to FR were able to achieve a more substantial increase in dry mass than did other genotypes. This is the first study to explain the differences in growth responses of a large number of tomato genotypes toward FR in their light environment.

scholarly journals FLAME RETARDANTS EFFECTS ON THE INITIAL GROWTH OF Schizolobium amazonicum HUBER EX DUCKE

2021 ◽  
Vol 45 ◽  
Author(s):  
Elen Silma Oliveira Cruz Ximenes ◽  
Andréa Carvalho da Silva ◽  
Adilson Pacheco de Souza ◽  
Josiane Fernandes Keffer ◽  
Alison Martins dos Anjos ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Leaf Area ◽  
Flame Retardants ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Initial Growth ◽  
Environmental Implications ◽  
Leaf Dry Mass ◽  
Height Increase ◽  
Positive Effect

ABSTRACT Flame retardants are efficient in fighting wildfire; however, their environmental implications, especially regarding the vegetation, need to be clarified. This work aimed at assessing the effects of flame retardant on the initial growth of Schizolobium amazonicum. Treatments consisted in applying different flame retardant concentrations via substrate and leaf: Phos-Chek WD-881® (0, 3.00, 6.00, 8.00 and 10.00 mL L-1), Hold Fire® (0, 7.00, 9.00, 12.00 and 15.00 mL L-1) and water-retaining polymer Nutrigel® used as alternative retardant (0, 0.25, 0.50, 0.75 and 1.00 g L-1). Growth analyses were carried out to assess the effects of these substances (10 repetitions per treatment). The aliquot of 10.00 mL L-1 of Phos-Chek WD881 applied on the leaves led to an increase of 70% in leaf area and 15% in seedling height. The same Phos-Chek concentration favored height increase (32%) and total dry mass accumulation (33%) throughout time. The concentration of 15 mL L-1 of Hold Fire® applied on leaves, compromised 45% the accumulation of dry biomass in the seedling. Initially, 1.00 g L-1 of Nutrigel® applied via substrate led to an increase of 70% in leaf area, 29% in plant height, and 89% in leaf dry mass. Therefore, Phos-Chek applied on leaves favored shoot growth in S. amazonicum. Hold Fire® applied on leaves impaired biomass accumulation in seedlings. Nutrigel® applied on substrate does not cause long-lasting damage to the initial growth of S. amazonicum. The aliquot of 0.50 g L-1 administered via polymer leave had positive effect on seedling shoot.

scholarly journals Soybeans Competitiveness with Morning Glory

2016 ◽  
Vol 34 (1) ◽  
pp. 25-33
Author(s):  
F. PICCININI ◽  
T.N. MARTIN ◽  
S.L.O. MACHADO ◽  
N.D. KRUSE ◽  
R. SCHMATZ
Keyword(s):  
Leaf Area ◽  
Dry Mass ◽  
Morning Glory ◽  
Replacement Series ◽  
Yield And Quality ◽  
Randomized Design ◽  
Total Plant ◽  
Soybean Plants ◽  
Herbicide Use

Weeds interfere negatively on development, yield and quality of soybeans (Glycine max). Inadequate weed control by herbicide use can select for resistant or tolerant biotypes, leading to a shift in the weed flora. An example is the increase of incidence of morning glory (Ipomoea spp.) in soybeans growing areas in South Brazil. The aim of this study was to determine the competitiveness of soybeans intercropped with I. triloba, I. indivisa and I. purpurea through a replacement experiments series. Greenhouse experiments were conducted in a completely randomized design with four replications. The first experiment was carried out aiming to get the plant population while total plant dry mass remained constant. Other experiments were done under replacement series experiments with soybeans and morning glory ratios of 100:0, 75:25, 50:50, 25:75 and 100:0 using the 250 plant m-2 defined by the preliminary experiment. Leaf area, root and shoots dry mass were assessed. Diagrams along with index interpretation were used to performed a competitiveness analysis. Soybeans showed greater competitiveness as I. triloba, I. purpurea and I. indivisa species for the leaf area, root and shoots dry mass variables. Intraspecific competition prevails between soybean plants whilst interspecific competition prevails for morning glory.

scholarly journals Does the climate of the origin control anatomical characteristics of the vessel elements as well as different foliar traits in Fagus crenata?

2011 ◽  
Vol 57 (No. 9) ◽  
pp. 377-383 ◽  
Author(s):  
V. Bayramzadeh ◽  
P. Attarod ◽  
M.T. Ahmadi ◽  
S. Rezaee Amruabadi ◽  
T. Kubo
Keyword(s):  
Leaf Area ◽  
Dry Mass ◽  
Fagus Crenata ◽  
Anatomical Characteristics ◽  
Vessel Area ◽  
Unit Leaf ◽  
Leaf Dry Mass ◽  
Vessel Elements ◽  
Foliar Traits ◽  
Area Percentage

The relationships between climatic factors and anatomical characteristics of the vessel elements as well as different foliar traits were investigated in Fagus crenata seedlings originating from different provenances. Fagus crenata samples were prepared from Chichibu Research Forest of Tokyo University. In the present study, vessel number per mm<sup>2</sup>, average vessel diameter, vessel area percentage, vessel element length, percentages of perforation plate types, transpiration rate, stomatal conductance, leaf area, leaf thickness, leaf dry mass per unit leaf area, stomatal density and stomatal pore length were measured. Vessel number per mm<sup>2</sup>, vessel area percentage, stomatal conductance, transpiration rate, leaf thickness and leaf dry mass per unit leaf area showed a significant negative correlation with yearly, winter, spring and autumn precipitation. The majority of the studied characteristics were not related to the mean annual and seasonal temperatures of the original provenances. The results suggest that anatomical characteristics of vessel elements and different foliar traits in Fagus crenata are mainly influenced by the precipitation of the origins.

Differential Growth of Two Common Groundsel (Senecio vulgaris) Biotypes

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 112-120 ◽  
Author(s):  
Jodie S. Holt ◽  
Steven R. Radosevich
Keyword(s):  
Resource Allocation ◽  
Leaf Area ◽  
Growth Parameters ◽  
High Light ◽  
Root Production ◽  
Differential Growth ◽  
Senecio Vulgaris ◽  
Light Regimes ◽  
Number Of Leaves ◽  
Common Groundsel

Comparative growth, development, and resource allocation of triazine - susceptible and triazine - resistant biotypes of common groundsel (Senecio vulgarisL.), grown under two light regimes, were studied over a 7 - week period. Dry-matter production, height, number of leaves, and leaf area of the susceptible biotype were greater than those of the resistant biotype at all harvests under both light regimes. Root/shoot ratios were lower in the resistant than in the susceptible biotype under high light. Lower values for these parameters in resistant plants are due to lowered photosynthetic capacity, which limits growth and lowers relative root production. Net assimilation rate (NAR) was lower in resistant than susceptible plants when grown under high light, but mean leaf area ratio over a harvest interval (L) of resistant plants was higher than that of susceptible plants under high light. Relative growth rate (RGR) was higher for susceptible plants before day 42 and higher for resistant plants after day 42 under high light. A lower plastochron index (PI) of resistant plants up to 5 weeks old, relative to susceptible plants of the same age, suggests that, when grown under high light, resistant plants are developmentally at least 2 days behind susceptible plants. Shading lowered dry-weight production, height, number of leaves, leaf area, NAR, RGR, PI and root/shoot ratios of both biotypes. Values for these growth parameters for susceptible plants were similar to or larger than for resistant plants when grown under low light. In both biotypes, resource allocation patterns and L shifted towards increased shoot and leaf production in response to shading.

scholarly journals Growth and biomass allocation of the C4 grasses Brachiaria brizantha and B. humidicola under shade

2000 ◽  
Vol 35 (12) ◽  
pp. 2335-2341 ◽  
Author(s):  
MOACYR BERNARDINO DIAS-FILHO
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Leaf Tissue ◽  
Experimental Period ◽  
High Light ◽  
Brachiaria Brizantha ◽  
Pasture Management ◽  
Low Light ◽  
Allocation Pattern ◽  
Full Sunlight

The growth and biomass allocation responses of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola were compared for plants grown outdoors, in pots, in full sunlight and those shaded to 30% of full sunlight over a 30day period. The objective was to evaluate the acclimation capacity of these species to low light. Both species were able to quickly develop phenotypic adjustments in response to low light. Specific leaf area and leaf area ratio were higher for low-light plants during the entire experimental period. Low-light plants allocated significantly less biomass to root and more to leaf tissue than high-light plants. However, the biomass allocation pattern to culms was different for the two species under low light: it increased in B. brizantha, but decreased in B. humidicola, probably as a reflection of the growth habits of these species. Relative growth rate and tillering were higher in high-light plants. Leaf elongation rate was significantly increased on both species under low light; however, the difference between treatments was higher in B. brizantha. These results are discussed in relation to the pasture management implications.

Cotton responses to different light–temperature regimes

1998 ◽  
Vol 131 (3) ◽  
pp. 277-283 ◽  
Author(s):  
D. ROUSSOPOULOS ◽  
A. LIAKATAS ◽  
W. J. WHITTINGTON
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Leaf Area ◽  
Temperature Regime ◽  
Light Regime ◽  
High Light ◽  
Cultivar Differences ◽  
Low Light ◽  
Temperature Regimes

A series of experiments investigating the interactive effects of light and temperature on vegetative growth, earliness, fruiting, yield and fibre properties in three cultivars of cotton, was undertaken in growth rooms. Two constant day/night temperature regimes with a difference of 4 °C (30/20 and 26/16·5 °C) were used throughout the growing season in combination with two light intensities (75 and 52·5 W m−2).The results showed that significant interactions occurred for most of the characters studied. Although the development of leaf area was mainly temperature-dependent, plants at harvest had a larger leaf area when high temperature was combined with low rather than with high light intensity. Leaf area was least in the low temperature–low light regime. However, the plants grown under the high temperature–low light combination weighed the least.Variations in the number of nodes and internode length were largely dependent on temperature rather than light. Light did, however, affect the numbers of branches, sympodia and monopodia. The first two of these were highest in the high light–high temperature regime and the third in the low light–low temperature regime.All other characters, except time to certain developmental stages and fibre length, were reduced at the lower light intensity. Variation in temperature modified the light effect and vice versa, in a character-dependent manner. More specifically, square and boll dry weights, as well as seed cotton yield per plant, were highest in high light combined with low temperature, where the most and heaviest bolls were produced. But flower production was favoured by high light and high temperature, suggesting increased boll retention at low temperature, especially when combined with low light. Low temperature and high light also maximized lint percentage.Fibres were shortest in the high temperature–high light regime, where fibre strength, micronaire index and maturity ratio were at a maximum. However, the finest and the most uniform fibres were produced when high light was combined with low temperature.Cultivar differences were significant mainly in leaf area and dry matter production at flowering.

scholarly journals Physiological and sanitary quality of soybean seeds harvested at different periods and submitted to storage1

2017 ◽  
Vol 47 (3) ◽  
pp. 312-320 ◽  
Author(s):  
Alan Mario Zuffo ◽  
Joacir Mario Zuffo Júnior ◽  
Everton Vinicius Zambiazzi ◽  
Fábio Steiner
Keyword(s):  
Mechanical Damage ◽  
Accelerated Aging ◽  
Dry Mass ◽  
Seed Vigor ◽  
Soybean Seeds ◽  
Adverse Conditions ◽  
Physiological Quality ◽  
Total Plant ◽  
Plant Dry Mass

ABSTRACT Delayed harvesting may affect the physiological quality of soybean seeds, due to adverse conditions in the field. This study aimed to evaluate the physiological and sanitary quality of soybean seeds (BRS 820 RR® cultivar) harvested at eight periods (0; 5; 10; 15; 20; 25; 30; and 35 days after the R8 phenological stage - full maturity) and stored for two periods (0 and 8 months). The following evaluations were carried out: moisture content, germination and emergence rate, emergence speed index, total plant dry mass, accelerated aging, electrical conductivity, mechanical damage, vigor and viability (tetrazolium) and sanitary quality of the seeds. The delayed harvesting of soybean seeds from 10 days after R8 impairs seed vigor and germination, in addition to increase the incidence of pathogens. Regardless of the harvesting period, the soybean seeds stored for eight months showed a reduction in their physiological quality, with an increase in the incidence of Phomopsis spp.

scholarly journals Allometry Between Vegetative and Reproductive Traits in Orchids

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing-Qiu Feng ◽  
Feng-Ping Zhang ◽  
Jia-Lin Huang ◽  
Hong Hu ◽  
Shi-Bao Zhang
Keyword(s):  
Leaf Area ◽  
Unit Area ◽  
Large Diameter ◽  
Reproductive Traits ◽  
Dry Mass ◽  
Reproductive Organs ◽  
Total Leaf Area ◽  
Vegetative Organs ◽  
Leaf Dry Mass ◽  
Inflorescence Length

In flowering plants, inflorescence characteristics influence both seed set and pollen contribution, while inflorescence and peduncle size can be correlated with biomass allocation to reproductive organs. Peduncles also play a role in water and nutrient supply of flowers, and mechanical support. However, it is currently unclear whether inflorescence size is correlated with peduncle size. Here, we tested whether orchids with large diameter peduncles bear more and larger flowers than those with smaller peduncles by analyzing 10 traits of inflorescence, flower, and leaf in 26 species. Peduncle diameters were positively correlated with inflorescence length and total floral area, indicating that species with larger peduncles tended to have larger inflorescences and larger flowers. We also found strongly positive correlation between inflorescence length and leaf area, and between total floral area and total leaf area, which suggested that reproductive organs may be allometrically coordinated with vegetative organs. However, neither flower number nor floral dry mass per unit area were correlated with leaf number or leaf dry mass per unit area, implying that the function between leaf and flower was uncoupled. Our findings provided a new insight for understanding the evolution of orchids, and for horticulturalists interested in improving floral and inflorescence traits in orchids.

scholarly journals Effect of Nickel Applications for the Control of Mouse Ear Disorder on River Birch

2005 ◽  
Vol 23 (1) ◽  
pp. 17-20 ◽  
Author(s):  
John M. Ruter
Keyword(s):  
Leaf Area ◽  
Nickel Sulfate ◽  
Normal Growth ◽  
Growing Season ◽  
Dry Mass ◽  
Shoot Length ◽  
Triple Superphosphate ◽  
Leaf Dry Mass ◽  
Birch Trees ◽  
Mouse Ear

Abstract Mouse ear (leaf curl, little leaf, squirrel ear) disorder has been a problem in container-grown river birch (Betula nigra L.) for several decades. The disorder is easy to detect in nurseries as the plants appear stunted due to shortened internodes which give the appearance of a witches-broom. The leaves are small, wrinkled, are often darker green in color, are commonly cupped and have necrotic margins. Plants grown in soil rarely express the disorder. A trial was initiated in June 2003 to determine if a deficiency of nickel was the cause of mouse-ear on river birch. Symptomatic river birch trees (Betula nigra ‘BNMTF’ Dura-Heat™) in their second growing season in #15 containers were selected for uniformity of size and mouse ear. Treatments included a 1) control, 2) 789 ppm Ni sprays, 3) 394 ppm Ni sprays, 4) 0.005 lbs Ni/yd3 as a drench, 5) 26 g/pot triple superphosphate (0–46–0), and 6) 130 g/pot Milorganite. Nickel was applied as nickel sulfate, whereas triple superphosphate and Milorganite contain trace amounts of nickel. At 16 days after treatment, up to 5 cm of new growth was evident on plants sprayed with nickel. Thirty days after treatment shoot length increased up to 60%, leaf area increased 80 to 83%, and leaf dry mass increased 76 to 81% for plants sprayed or drenched with nickel sulfate. Plants treated with triple superphosphate or Milorganite did not resume normal growth. All plants treated with nickel sulfate in 2003 did not show symptoms of mouse ear after initiation of growth in 2004. Based on this research mouse ear disorder of river birch is caused by a deficiency of nickel which can be corrected by foliar or drench applications of nickel sulfate.

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