Growth response of western hemlock and Douglas-fir seedlings to temperature regimes during day and night

1971 ◽  
Vol 49 (2) ◽  
pp. 289-294 ◽  
Author(s):  
H. Brix
Keyword(s):  
Dry Matter ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Stem Length ◽  
Dry Matter Production ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Matter Production ◽  
Production And Distribution ◽  
Growing Conditions

Growth of western hemlock and Douglas-fir seedlings was studied under 11 controlled day–night temperature regimes ranging from 8 to 28 °C, and with light intensities of 450 and 1000 ft-c for 100 days after seed germination. Production and distribution of dry matter, together with length and diameter of stem, were measured. Douglas fir had a broad optimum temperature for growth between 18 and 24 °C, whereas hemlock had a pronounced optimum at 18 °C, especially at high light. High temperature was more detrimental to growth of hemlock than of Douglas fir. At 28 °C, dry matter production of hemlock was 7, and of Douglas fir 40% of the maximum. Low temperature similarly affected the two plants. A constant day–night temperature regime was as good or better than alternating temperatures for both plants. Day temperature was more effective in increasing growth than night temperature. Light intensity, for most temperature regimes, had a pronounced effect on dry matter production, less on stem diameter, and little or none on stem length. Dry matter production of hemlock was considerably lower than for Douglas fir for all growing conditions.

AN ANALYSIS OF DRY MATTER PRODUCTION OF DOUGLAS-FIR SEEDLINGS IN RELATION TO TEMPERATURE AND LIGHT INTENSITY

1967 ◽  
Vol 45 (11) ◽  
pp. 2063-2072 ◽  
Author(s):  
Holger Brix
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Dry Matter Distribution ◽  
Pronounced Increase ◽  
Light Intensities ◽  
Matter Production ◽  
Net Assimilation

Seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were grown in growth chambers under all combinations of three temperatures (13, 18, and 24 °C) and three light intensities (450, 1000, and 1800 ft-c). Dry matter production of leaves, stem, and roots was determined at 65 and 100 days after germination. The leaf area produced per unit of leaf dry weight and the dry matter distribution to the plant organs was measured. Net assimilation rates between the ages of 65 and 100 days were calculated. Rates of photosynthesis per unit of leaf were determined at different light intensities and temperatures, and rates of respiration of plant top and of roots were found for different temperatures.Increasing light intensity affected dry matter production in two opposing ways: (i) it increased the rate of photosynthesis per unit leaf area, and (ii) it decreased the leaf area added per unit of dry matter produced. A pronounced increase in growth with increase in temperature from 13 to 18 °C was a result of a temperature influence on production of leaf area rather than the effect of photosynthesis per unit of leaf. Net assimilation rates decreased with increase in temperature at all light intensities.

Above- and below-ground net production in 40-year-old Douglas-fir stands on low and high productivity sites

1981 ◽  
Vol 11 (3) ◽  
pp. 599-605 ◽  
Author(s):  
Michael R. Keyes ◽  
Charles C. Grier
Keyword(s):  
Fine Roots ◽  
Dry Matter ◽  
Net Primary Production ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Net Production ◽  
High Productivity ◽  
Matter Production ◽  
Below Ground ◽  
Productivity Potential

Above- and below-ground net primary production was estimated for 40-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands growing on sites with apparently large differences in productivity potential. Aboveground net production was estimated from direct measurements of tree growth; belowground productivity was derived from data obtained by sorting live and dead roots from soil cores used in combination with measurements of root growth on observation windows.Aboveground net production was 13.7 t•ha−1 on the high productivity site and 7.3 t•ha−1 on the low productivity site. Belowground dry matter production on the high productivity site was 4.1 t•ha−1 compared with 8.1 t•ha−1 for the poorer site. On the more productive site, 8% of total stand dry matter production was in fine roots in contrast to over 36% on the poorer site. The difference in total net production (aboveground plus belowground) between the two sites was small (2.4 t•ha−1). Apparent differences in aboveground productivity may, to a large extent, result from the need for a greater investment in the fine roots on harsher sites.

scholarly journals Effects of nitrogen fertilizer and elevated CO2 on dry matter production and yield of rice cultivars

1970 ◽  
Vol 34 (2) ◽  
pp. 313-322 ◽  
Author(s):  
MA Razzaque ◽  
MM Haque ◽  
MA Hamid ◽  
QA Khaliq ◽  
ARM Solaiman
Keyword(s):  
Elevated Co2 ◽  
Field Condition ◽  
Dry Matter ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Optimum Dose ◽  
Rice Cultivars ◽  
Nitrogen Levels ◽  
Matter Production ◽  
Growing Conditions

A pot experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the year 2003 to find out the dry matter production and yield of rice cultivars under different nitrogen levels and growing conditions. Thirty-day old single seedlings were transplanted in pot and were placed in 3 growing conditions, such as i) Open top chamber (OTC) with elevated CO2 (570 ± 50 ppm), ii) OTC with ambient CO2 (360 ± 50 ppm), and iii) open field condition. The three nitrogen levels used were, i) control, ii) optimum dose, and iii) supra optimum dose. Three rice cultivars used in the experiment were, i) BRRI dhan 39, ii) Khashkani, and iii) Shakkarkhora. Rice yield and dry matter production respond significantly to different environments. Increasing atmospheric CO2 increased grain yield. Stem dry weight, leaf dry weight, leaf sheath dry weight and root dry weight were increased in elevated CO2 than ambient CO2 and field condition. BRRI dhan 39 gave highest yield (50.82 g/plant) at supra optimum N level in elevated CO2. Local variety gave similar result under elevated CO2 in optimum and supra optimum N levels. The lowest yield (15.09 g/plant) was produced by Shakkorkhora in field condition with no nitrogen application. Key Words: Nitrogen; elevated CO2; yield; dry matter.DOI: 10.3329/bjar.v34i2.5804Bangladesh J. Agril. Res. 34(2): 313-322, June 2009

Temperature Effects on Vegetative Growth of Round-Leaved Mallow (Malva pusilla)

Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 63-67
Author(s):  
Robert E. Blackshaw
Keyword(s):  
Vegetative Growth ◽  
Dry Matter ◽  
Weight Ratio ◽  
Control Program ◽  
Effective Control ◽  
Dry Matter Accumulation ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Matter Production ◽  
C Partitioning

Vegetative growth response of round-leaved mallow to various day/night temperature regimes was studied under controlled-environment conditions to predict its potential geographic distribution and to develop an effective control program. Round-leaved mallow dry matter production was greatest with day temperatures of 18 to 26 C. Dry matter accumulation was reduced by a night temperature of 6 C but was minimally affected by night temperatures ranging from 12 to 24 C. Regression analysis predicted minimal vegetative growth at mean daily temperatures below 8 C and above 30 C, with optimum growth at 20 C. Partitioning of round-leaved mallow biomass in leaves, stems, and roots was affected by temperature. Maximum leaf weight ratio occurred at low temperatures, 10 C day and 6 C night. Stem weight ratio was greatest at a day temperature of 26 C, with night temperature having little effect. Maximum root biomass occurred with a day temperature of 18 C. Results are discussed in terms of environmental conditions that allow round-leaved mallow to be an effective competitor with crops and potential approaches for its control.

scholarly journals Initial Growth of Rosebay Rhododendron Seedlings as Influenced by Day and Night Temperatures

HortScience ◽  
1993 ◽  
Vol 28 (7) ◽  
pp. 705-707 ◽  
Author(s):  
Mark C. Starrett ◽  
Frank A. Blazich ◽  
Stuart L. Warren
Keyword(s):  
Dry Matter ◽  
Weight Ratio ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Similar Response ◽  
Initial Growth ◽  
Night Temperature ◽  
Root Dry Weight ◽  
Matter Production ◽  
Total Plant

Rosebay rhododendron (Rhododendron maximum L.) seedlings were grown in controlled-environment chambers for 14 weeks under long (9-hour) days at 18, 22, 26, or 30C in factorial combination with 15-hour nights at 14, 18, 22, or 26C. Total dry-matter production was lowest for 18C days and highest for 26C days. A similar response occurred for top, leaf, root, and stem dry weights. Nights at 22C maximized total plant, top, leaf, and stem dry weights. The optimum day/night cycle for dry-matter production was 26/22C. Leaf area was optimum with 18C nights. Leaf weight ratio (leaf dry weight: total plant dry weight) increased with an increase in night temperature to a maximum at 22C. Root weight ratio (root dry weight: total plant dry weight) decreased with an increase in night temperature to a minimum at 22C. Stem weight ratio (stem dry weight: total plant dry weight) and shoot: root ratio (top dry weight: root dry weight) were not influenced significantly by day or night temperature. A day/night cycle of 26/22C seems to be optimal for producing-salable plants.

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