Effect of gibberellic acid on growth and photosynthesis in Abies balsamea

1975 ◽  
Vol 53 (17) ◽  
pp. 1805-1810 ◽  
Author(s):  
C. H. A. Little ◽  
K. Loach
Keyword(s):  
Gibberellic Acid ◽  
Abies Balsamea ◽  
Foliar Spray ◽  
Weight Ratio ◽  
Normal Growth ◽  
Net Photosynthesis ◽  
Height Growth ◽  
Balsam Fir ◽  
Root Weight ◽  
Productive Capacity

The hypothesis that exogenous gibberellic acid (GA3) increases height growth in tree species partly because it stimulates the rate of net photosynthesis (PN) was investigated in the conifer balsam fir (Abies balsamea L.). In long-term experiments, the normal growth pattern of 4- and 5-year-old potted trees was changed by GA3 applied in both an aqueous soil drench (20 mg per tree, thrice weekly; or 50 mg per tree, twice weekly) and a foliar spray (1000 ppm, weekly) for about 3 months. Effects included increased longitudinal and radial growth in the leader and longest lateral in the uppermost whorl, enhancement of shoot apical dominance, increased needle length, and decreased root weight – top weight ratio. Nevertheless, the Pn and productive capacity of the current and 1-year-old needles in the GA3-treated and control trees were the same, measured during and at the end of the treatment period. In short-term experiments, the 1000-ppm GA3 spray did not affect PN of current-year needles, measured 3 h up to 7 days after one or two applications. PN of current-year cuttings also was not altered by feeding through the basal end (1) 0.25, 2.5, 25, or250 ppm GA3 for 4 h; or(2) 10 or 100 ppm GA3 for24 h. Feeding25 or250 ppm GA3 for 48 h through the distal portion of an attached, current shoot decreased PN in the proximal portion. Collectively, the results indicate that exogenous GA3 increases height growth in balsam fir by altering the normal distribution of photosynthate, not through increasing photosynthate production.

Gibberellic acid induced growth acceleration in Populus hybrids

1984 ◽  
Vol 14 (6) ◽  
pp. 850-854 ◽  
Author(s):  
S. B. Rood ◽  
G. Daicos ◽  
T. J. Blake
Keyword(s):  
Gibberellic Acid ◽  
Leaf Area ◽  
Foliar Spray ◽  
Dry Weight ◽  
Height Growth ◽  
Total Leaf Area ◽  
Leaf Production ◽  
Relative Growth ◽  
Shoot Dry Weight ◽  
Net Assimilation

Weekly applications of 0.4 mg gibberellic acid (GA) in 8 μL 95% ethanol micropipetted onto shoots of rooted cuttings increased Populuseuramericana (Dode) Guinier height growth by 54% and shoot dry weight by 25% after 21 days. Total leaf area increased by 21% as a result of more rapid leaf production and slightly larger leaf sizes. Root growth was unaffected by GA treatment. The observed GA-induced acceleration resulted from an increase in relative growth rate while mean net assimilation rate was unaffected. Owing to a substantial increase in the number and size of leaves, the leaf area ratio, representing the ratio of photosynthesizing to respiring material, increased. While direct micropipette application of GA promoted height growth and primary shoot dry weight accumulation, GA application through either foliar spray or soil drench also promoted the growth of secondary shoots. Application of GA to shoots was more effective in promoting shoot growth than application through the roots. Direct GA application also promoted the growth of P. alba L. × P. grandidentata Michx. and P. × canescens (Ait.) Smith × P. alba × P. grandidentata. Thus, GA can be used for hastening early growth of these trees under winter greenhouse conditions.

Production, storage, and use of photosynthate during shoot elongation in balsam fir (Abies balsamea)

1973 ◽  
Vol 51 (6) ◽  
pp. 1161-1168 ◽  
Author(s):  
K. Loach ◽  
C. H. A. Little
Keyword(s):  
Dry Matter ◽  
Dark Respiration ◽  
Abies Balsamea ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Extension Growth ◽  
Balsam Fir ◽  
Photosynthetic Production ◽  
Intermediate Time

Rates of net photosynthesis and dark respiration of 1-year-old and currently developing foliage were measured in the uppermost (i.e. 1-year-old) whorl of branches of 6-year-old balsam fir trees (Abies balsamea (L.) Mill.) during the period of extension growth of the current shoot. The rates were integrated to estimate net dry matter production by the two ages of foliage, and compared with dry matter requirements for growth of the new shoot (estimated from a regression equation of length over dry weight), and with cambial growth in the 1-year-old shoot (estimated from periodic harvests). The surplus of production over use in these two sinks was stored temporarily in the 1-year-old foliage or exported from the branch, the latter predominating. Two periods in which a large proportion of the photosynthetic production was exported (corresponding roughly to the months of May and July) were separated by a period when export was relatively low. At this intermediate time, current photosynthetic production was minimal and local growth demands were at their highest. Photosynthates stored in the 1-year-old foliage before budbreak supplemented current photosynthesis and permitted export to continue, except for a few days at the end of June. The contribution from stores in the old foliage, however, never exceeded one-third of current photosynthetic production. When extension growth terminated, a second transient storage peak occurred in the 1-year-old foliage for about 2 weeks. These observations explain the commonly observed reduction in root growth during current shoot extension, and corroborate results from studies made by other investigators using radioactive tracers.

scholarly journals Climate change experiment suggests divergent responses of tree seedlings in eastern North America’s Acadian Forest Region over the 21st century

2021 ◽  
Author(s):  
William Robert Vaughn ◽  
Anthony R. Taylor ◽  
David A. MacLean ◽  
Loïc D'Orangeville ◽  
Michael B. Lavigne
Keyword(s):  
Soil Moisture ◽  
Abies Balsamea ◽  
Height Growth ◽  
Red Spruce ◽  
Balsam Fir ◽  
Red Maple ◽  
Drought Effect ◽  
Growth And Survival ◽  
Forest Region ◽  
Acadian Forest

In this study, we conducted a controlled experiment to assess the growth and survival of balsam fir (Abies balsamea (L.) Mill.), red spruce (Picea rubens Sarg.), and red maple (Acer rubrum L.) seedlings in response to warming, drought, and elevated CO2, as projected under RCP 8.5 for North America’s Acadian Forest Region. In response to warming, only red spruce increased in height; however, this effect varied by CO2 and soil moisture treatments. Under the drought treatment, red spruce biomass was not affected, but mortality increased by two percent. With warming, increases in balsam fir height growth were only detected under certain soil moisture and CO2 conditions. Balsam fir biomass decreased by 24% under drought, while mortality increased by 5 percent. Warming did not improve red maple height growth, but it remained 7-50 times greater than that of the conifers and no mortality was observed. Overall, CO2 enrichment increased height growth of droughted seedlings relative to the ambient treatment, demonstrating an amelioration of the negative drought effect. Balsam fir was the least adapted to warming and drought, while red spruce displayed some positive responses. Although growth of red maple seedlings did not increase with warming, they exhibited greater absolute growth and survival, which suggests red maple may outperform both conifers under a warming climate.

Growth of Lotus creticus creticus and Cynodon dactylon under two levels of irrigation

2002 ◽  
Vol 53 (12) ◽  
pp. 1375 ◽  
Author(s):  
O. R. Vignolio ◽  
C. Biel ◽  
F. de Herralde ◽  
J. P. L. Araújo-Alves ◽  
R. Savé
Keyword(s):  
Leaf Area ◽  
Hydraulic Resistance ◽  
Cynodon Dactylon ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Green Leaf ◽  
Shoot Biomass ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Green Leaf Area

Soils with scarce plant covering are very susceptible to water and wind erosion. Two species recommended for permanent cover of soil are Lotus creticus creticus and Cynodon dactylon. The performance of both species cultivated in pure stands and in mixture and with 2 watering regimes, high (12.64 L/bag) and low (8.36�L/bag), was analysed in polyethylene bags between March and July in greenhouse conditions. With low watering the growth of both species was lower but mortality of plants was not observed. Growth of stems in L.�creticus and stolons in C. dactylon did not stop with low watering. The growth of C. dactylon was higher than that of L. creticus at both watering regimes. Total root and green shoot biomass of each species was affected by watering. Green leaf area, root weight ratio, root hydraulic resistance, and watering efficiency (g biomass/L watering) differed with the combination of species. Green leaf area, root hydraulic resistance, and watering efficiency were higher in C. dactylon than in L. creticus. Root weight ratio was higher in L. creticus than in C. dactylon, but the specific length and area of roots were higher in C. dactylon than in L. creticus. Net photosynthesis rate of each species was only affected by watering regime. Performance of both species was not affected by the mixture and it has the potential to be a successful ground cover.

Chronologie de la croissance chez des semis de sapin baumier (Abies balsamea (L.) Mill.) après une coupe à blanc avec protection de la régénération

2002 ◽  
Vol 78 (6) ◽  
pp. 876-885 ◽  
Author(s):  
Sylvain Parent ◽  
Jean-Claude Ruel
Keyword(s):  
Abies Balsamea ◽  
Ring Width ◽  
Complete Removal ◽  
Moisture Stress ◽  
Height Growth ◽  
Balsam Fir ◽  
White Birch ◽  
Strong Response ◽  
Seedling Bank ◽  
Wide Range

The method of harvesting with protection of the advanced regeneration consists of a complete removal of the main canopy to release a seedling bank established under the overstory shade. After harvesting, seedlings acclimated to understory conditions could suffer from moisture stress, especially the small, juvenile seedlings (less than six years). The objective of the study is to determine the capacity of understory-acclimated balsam fir seedlings to respond positively and immediately to release. The response to release was studied in two seedling populations belonging to two distinct climatic regions of Quebec, the Western and the Eastern sections of the balsam fir-white birch ecological domain. Results show that the response patterns were similar in both populations. Response to release occurred in two steps. One year after harvesting, basal ring width was on the average five times larger than prior to harvesting (p > 0.001). Height growth only became significantly higher the second year after release (p < 0.001). On average, juveniles showed higher height growth rates (height growth/height) than older seedlings. This rate was negatively correlated to seedling height at harvesting (r = -0,68, p < 0.001). Our study clearly shows that balsam fir seedlings can respond immediately and positively to large openings. The strong response of juvenile seedlings to release indicates that these can contribute significantly to the future stand. The geographic and climatic differences between the two stands under study suggest that these observations apply to a wide range of balsam fir stands. Key words: advance growth, balsam fir, release

scholarly journals Effects of exogenous and foliar applications of Brassinosteroid (BRs) and salt stress on the growth, yield and physiological parameters of Lycopersicon esculentum (Mill.)

2017 ◽  
Vol 4 (3) ◽  
pp. 88-101 ◽  
Author(s):  
Muhammad Irfan ◽  
Jan Alam ◽  
Imran Ahmad ◽  
Imtiaz Ali ◽  
Humaira Gul
Keyword(s):  
Salt Stress ◽  
Lycopersicon Esculentum ◽  
Plant Height ◽  
Root Length ◽  
Foliar Spray ◽  
Weight Ratio ◽  
Growth Yield ◽  
Root Weight ◽  
Salinity Levels ◽  
Number Of Leaves

The germination response of Lycopersicon esculentum was studied on different salinity levels from control (non-saline), 0.2,0.4,0.6 and 0.8% NaCl solution. Seeds germinating under salt stress exhibited decrease in saline media as compared to respective control. Seeds germinating with salinity and brassinosteroid (applied exogenously through roots and as foliar spray, 0.25 and 0.5 ppm) exhibited promotion in control as compared to their respective saline media. Plants treated with different salts concentrations (60 and 100mM) NaCl exhibited reduction in plant height, root length, number of leaves, number of fruits and biomass as compared to control while brassinosteroid having concentrations of 0.25 and 0.5 ppm (applied through roots and as foliar spray) caused promotion in plant height, root length, number of leaves, number of fruits and biomass in saline and non saline media. Plants treated with different salts concentration of (60 and 100mM) NaCl exhibited increase in Relative water content, leaf water loss, electrolyte leakage, shoot/- root ratio, root/- weight ratio and leaf/- weight ratio at both NaCl concentrations (60 and 100 mM) as compared to control, while stem/- weight ratio showed reduction at both salinity levels as compared to control while brassinosteroid applied in roots and as a foliar spray at 0.25 and 0.5 ppm concentrations exhibited reduction in stem/- weight ratio at high NaCl level (100 mM) as compared to control. 

scholarly journals Testing the potential of LEDs to enhance growth and quality characteristics of Salvia fruticosa

2019 ◽  
Vol 46 (No. 2) ◽  
pp. 98-106 ◽  
Author(s):  
Filippos Bantis ◽  
Kalliopi Radoglou
Keyword(s):  
Root Biomass ◽  
Weight Ratio ◽  
Dry Weight ◽  
Total Phenolic ◽  
Root Weight ◽  
Light Emitting ◽  
Shoot Dry Weight ◽  
Radiation Spectra ◽  
Salvia Fruticosa ◽  
Developmental Characteristics

The effect of light-emitting diodes (LED) with broad radiation spectra on developmental, physiological, and phytochemical characteristics of Greek sage (Salvia fruticosa L.) seedlings was assessed. Fluorescent (FL – control) tubes and four LED lights [AP67 (moderate blue, red and far-red), L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red) and NS1 (high blue and green, low red, high red : far-red, 1% ultraviolet)] were used in a growth chamber. Seedlings grown under FL, L20AP67 and AP673L exhibited the best morphological and developmental characteristics. FL led to inferior root biomass formation compared to all LEDs. AP67 promoted greater root-to-shoot dry weight ratio and dry-to-fresh overground and root weight ratios, but induced the least morphological and developmental characteristics. NS1 performed well regarding the root biomass production. Total phenolic content and the root growth capacity were not significantly affected. The present study demonstrates that L20AP67 and AP673L LEDs performed equally to FL light regarding the developmental characteristics. AP67 and NS1 may have the potential to be used for compact seedling production.

Weather and Outbreaks of the Spruce Budworm in the Province of Quebec from 1939 to 1956

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
The Past ◽  
Forest Regions ◽  
Tree Component ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.

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