Growth responses of Urtica dioica to nutrient supply

1995 ◽  
Vol 73 (6) ◽  
pp. 843-851 ◽  
Author(s):  
Miroslav Šrůtek
Keyword(s):  
Biomass Allocation ◽  
Clonal Plant ◽  
Reproductive Organs ◽  
Nutrient Supply ◽  
Urtica Dioica ◽  
Growth Responses ◽  
Shoot Height ◽  
Key Words Allometry ◽  
P 16 ◽  
Lateral Branches

This study examines the effects of nutrient supply (three N–P–K treatments: 75, 225, and 375 kg∙ha−1; 12.5% N, 8.5% P, 16% K) on growth, allometry, and architecture of Urtica dioica L., an expansive clonal plant found throughout Central Europe. Biomass allocation was significantly affected by nutrient supply: higher nutrient doses resulted in less biomass allocation to belowground organs, whereas the period of intensive production of aboveground biomass was prolonged. Shoot height increases with nutrient supply. The height ratios were constant over time. Within each treatment and each harvest, inflorescence biomass was positively correlated with shoot height. Branching of the main shoots (number of lateral branches) was positively correlated with plant height and changed with time. The number of new rhizomes was affected by both treatment and harvest, especially in older plants. The results suggest that high nutrient supply increased the allocation of biomass both to reproductive organs and to vegetative organs. Key words: allometry, biomass allocation, clonal plant, nutrients, plant architecture, Urtica dioica.

scholarly journals Effects of mycorrhizal inoculant, N:P supply ratio, and water depth on the growth and biomass allocation of three wetland plant species

2005 ◽  
Vol 83 (9) ◽  
pp. 1117-1125 ◽  
Author(s):  
Lauchlan H. Fraser ◽  
Larry M. Feinstein
Keyword(s):  
Biomass Allocation ◽  
Water Depth ◽  
Soil Surface ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Nutrient Supply ◽  
Wetland Plant ◽  
Below Ground ◽  
Root:Shoot Ratios ◽  
Water Depths

In the greenhouse, we investigated the growth and biomass allocation of three juvenile wetland species ( Carex tribuloides Wahl., Phalaris arundinacea L., and Rumex orbiculatus Gray) under three different water depths (–4, 0, and +2 cm relative to the soil surface), three N:P supply ratios (1:30, 1:1, 30:1), and two mycorrhizal inoculant treatments (arbuscular mycorrhizal (AM) fungi present, absent). After 6 weeks, the plants were harvested, separated to above- and below-ground parts, oven-dried, and weighed. The mycorrhizal inoculant significantly increased plant growth and reduced root:shoot ratios. At an N:P supply ratio of 30:1, plants with AM fungi had significantly greater biomass than those plants without AM fungi. However, at 1:1 N:P supply ratio, plants without AM fungi had greater biomass. Plants without AM fungi had higher root:shoot ratios at 0 and –4 cm water depth than plants with AM fungi. In general, C. tribuloides had the lowest growth, and unlike P. arundinacea and R. orbiculatus, was not affected by the water depth treatment. Growth of the wetland plants was limited more by nitrogen than by phosphorus. Our results suggest that at high N:P nutrient supply ratios and non-flooded conditions the growth of wetland seedlings can benefit by being inoculated with AM fungi.

scholarly journals Red hot maples: Acer rubrum first-year phenology and growth responses to soil warming

2017 ◽  
Vol 47 (2) ◽  
pp. 159-165 ◽  
Author(s):  
J.A. Wheeler ◽  
N.M. Gonzalez ◽  
K.A. Stinson
Keyword(s):  
Biomass Allocation ◽  
Environmental Conditions ◽  
Acer Rubrum ◽  
Growing Season ◽  
Tree Seedlings ◽  
Red Maple ◽  
Growth Responses ◽  
Soil Warming ◽  
Leaf Production ◽  
Trade Offs

Microhabitat environmental conditions are an important filter for seedling establishment, controlling the availability of optimal recruitment sites. Understanding how tree seedlings respond to warming soil temperature is critical for predicting population recruitment in the future hardwood forests of northeastern North America, particularly as environmental conditions and thus optimal microhabitat availabilities change. We examined the effect of soil warming of 5 °C during the first growing season on germination, survival, phenology, growth, and stem and root biomass allocation in Acer rubrum L. (red maple) seedlings. While there was no effect of soil warming on germination or survival, seedlings growing in warmer soils demonstrated significantly accelerated leaf expansion, delayed autumn leaf senescence, and an extended leaf production period. Further, seedlings growing in warmer soils showed larger leaf area and stem and root structures at the end of the first growing season, with no evidence of biomass allocation trade-offs. Results suggest that A. rubrum seedlings can capitalize on soil warming by adjusting leaf phenology and leaf production, resulting in a longer period of carbon uptake and leading to higher overall biomass. The absence of growth allocation trade-offs suggests that A. rubrum will respond positively to increasing soil temperatures in northeastern forests, at least in the early life stages.

scholarly journals How does nitrogen shape plant architecture?

2020 ◽  
Vol 71 (15) ◽  
pp. 4415-4427 ◽  
Author(s):  
Le Luo ◽  
Yali Zhang ◽  
Guohua Xu
Keyword(s):  
Cell Division ◽  
Crop Production ◽  
Plant Architecture ◽  
Reproductive Organs ◽  
N Fertilization ◽  
High Yield ◽  
Shoot Branching ◽  
Shoot Height ◽  
Plant Nitrogen ◽  
N Supply

Abstract Plant nitrogen (N), acquired mainly in the form of nitrate and ammonium from soil, dominates growth and development, and high-yield crop production relies heavily on N fertilization. The mechanisms of root adaptation to altered supply of N forms and concentrations have been well characterized and reviewed, while reports concerning the effects of N on the architecture of vegetative and reproductive organs are limited and are widely dispersed in the literature. In this review, we summarize the nitrate and amino acid regulation of shoot branching, flowering, and panicle development, as well as the N regulation of cell division and expansion in shaping plant architecture, mainly in cereal crops. The basic regulatory steps involving the control of plant architecture by the N supply are auxin-, cytokinin-, and strigolactone-controlled cell division in shoot apical meristem and gibberellin-controlled inverse regulation of shoot height and tillering. In addition, transport of amino acids has been shown to be involved in the control of shoot branching. The N supply may alter the timing and duration of the transition from the vegetative to the reproductive growth phase, which in turn may affect cereal crop architecture, particularly the structure of panicles for grain yield. Thus, proper manipulation of N-regulated architecture can increase crop yield and N use efficiency.

Hormone growth responses of roots of shoot height mutants of pea

2007 ◽  
Vol 129 (4) ◽  
pp. 813-821 ◽  
Author(s):  
Thomas Silva ◽  
Peter J. Davies
Keyword(s):  
Growth Responses ◽  
Shoot Height

Effects of ontogeny and soil nutrient supply on production, allocation, and leaf area efficiency in loblolly and slash pine stands

2000 ◽  
Vol 30 (10) ◽  
pp. 1511-1524 ◽  
Author(s):  
Eric J Jokela ◽  
Timothy A Martin
Keyword(s):  
Leaf Area ◽  
Weed Control ◽  
Loblolly Pine ◽  
Aboveground Biomass ◽  
Soil Nutrient ◽  
Growth Efficiency ◽  
Pinus Elliottii ◽  
Nutrient Supply ◽  
Slash Pine ◽  
Growth Responses

The effects of ontogeny and soil nutrient supply on aboveground biomass accumulation, allocation, and stemwood growth efficiency of loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm. var. elliottii) were investigated in north-central Florida over 16 years using a 2 × 2 × 2 factorial experiment (species, fertilization, weed control). Aboveground biomass growth responses to the combined fertilizer and weed control treatments (FW) averaged ~2- and 2.8-fold for slash and loblolly pine, respectively. In the same treatment, annual needlefall (NF) production for slash pine approached a "steady state" of 6 Mg·ha-1 at ages 8-14 years, while loblolly pine NF production peaked at 7 Mg·ha-1 at age 10 years, and then declined 17% following curtailment of the fertilizer treatment. Periodic stemwood biomass increment (PAI) for the FW treatment for both species culminated at about 15 Mg·ha-1·year-1 at age 8 years and then declined rapidly (~275%) to <4 Mg·ha-1·year-1 at 15 years; reductions for the untreated control were considerably slower. The progressive decline in PAI following peak leaf area development was closely associated with a decrease in stemwood production per unit leaf area (growth efficiency). A unit increase in leaf area index in the 7- to 9-year-old stands produced about 3.0 and 3.1 times more stemwood biomass per year than in the 14- to 16-year-old stands for loblolly and slash pine, respectively.

scholarly journals Growth of `Cunningham's White' Rhododendron in Plastic and Fiber Pots Treated With Copper Hydroxide

2002 ◽  
Vol 12 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Sven E. Svenson
Keyword(s):  
Root Growth ◽  
Dry Weight ◽  
Growth Responses ◽  
Copper Hydroxide ◽  
Shoot Height ◽  
Copper Treatment ◽  
Average Maximum ◽  
Growing Block ◽  
Black Plastic ◽  
Maximum Temperatures

Shoot and root growth responses of `Cunningham's White' rhododendron (Rhododendron x) was studied when grown in black plastic or molded fiber pots treated with copper hydroxide, or not treated. Containers of two sizes were studied, and the influence of pot type on substrate temperature was recorded. Rhododendron shoot height and dry weight was not influenced by pot volume, pot type, or copper treatment at 49, 131, or 362 d after potting. Rhododendron shoots were larger when grown in 3.8-L (trade 2-gal) pots compared to 2.8-L (trade 1-gal) pots, or when grown in 3.8-L fiber pots compared to 3.8-L plastic pots, both 131 and 362 d after potting. Copper treatment did not influence shoot size. Copper treatment reduced the amount of circling or matted roots at the container-substrate interface for both plastic and fiber pots, but there was better control of root growth in 3.8-L pots compared to 2.8-L pots. Substrate average minimum temperatures were warmer, and average maximum temperatures were cooler when pots were located near the center of the growing block compared to the southwest corner ofthe growing block. Substrate average maximum temperatures were cooler in fiber pots compared to plastic pots, but only when pots were located on the southwest corner of the growing block.

scholarly journals Uso da subirrigação para imposição de estresse hídrico em sistema semi-contínuo para medição de CO2

2015 ◽  
Vol 21 (2) ◽  
pp. 235 ◽  
Author(s):  
Rhuanito Soranz Ferrarezi ◽  
Marc W. Van Iersel ◽  
Roberto Testezlaf
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Plant Growth ◽  
Net Photosynthesis ◽  
Dry Mass ◽  
Co2 Exchange ◽  
Carbon Gain ◽  
Growth Responses ◽  
Shoot Height ◽  
Soil Moisture Sensors

The objectives of this work were to evaluate the effects of distinct moisture contents to trigger subirrigation on salvia photosynthesis and plant growth, and to verify the feasibility of subirrigation use in water stress imposition research in this crop. We evaluated two substrate volumetric water contents (VWC) as treatments (0.2 and 0.4 m3 m-3) to trigger subirrigation, with 4 replications. Each replication was composed of 10 plants. An automated semi-continuous multi-chamber crop CO2-exchange system was used, with capacitance soil moisture sensors for continuous moisture monitoring. Manual subirrigation with nutrient solution was performed when VWC dropped below the thresholds. In both treatments, the values of net photosynthesis, daily carbon gain and carbon use efficiency reduced over time, from 2 to 1.1 μmol s-1 from 2.2 to 1 μmol d-1 from 0.7 to 0.45 mol mol-1, respectively, in both soil moisture treatments. Total shoot dry mass (p=0.0129), shoot height in the tip of the highest flower (p&lt;0.0001) and total leaf area (p=0.0007) were statistically higher at 0.4 m3 m-3 treatment. The subirrigation system was not efficient to impose water stress, due to excessive variation on VWC values after each irrigation event in both treatments. Higher soil moisture promoted positive plant growth responses in salvia cultivated by subirrigation.

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