scholarly journals Growth reactions of carnation, measured by net photosynthesis, on different air contents of the soil.

1970 ◽  
Vol 18 (3) ◽  
pp. 149-157
Author(s):  
A.L.M. Van Wijk ◽  
J. Buitendijk
Keyword(s):  
Light Intensity ◽  
Dry Matter ◽  
Dianthus Caryophyllus ◽  
Net Photosynthesis ◽  
Constant Level ◽  
Fresh Matter ◽  
Soil Air ◽  
Air Content ◽  
Light Intensities ◽  
Matter Production

In pot experiments, Dianthus caryophyllus plants grown for 2 1/2 months at soil-air levels of 20, 10 or 5% (v/v) produced approx. equal amounts of dry matter, but fresh-matter production at 5 and 10% soil air was 13 and 2% lower than at 20% soil air. The effect of aeration on growth (photosynthesis) increased with increasing light intensity. Decreasing content of soil air from 20, 10 and 5% to 5 and 2.5% respectively was accompanied by an immediate reduction of photosynthesis to a fairly constant level. This reduction increased with increasing light intensity. An increase in soil air from 2.5 to 20, 10 or 5% gave a recovery of photosynthesis which at the two lowest light intensities was complete within 1-3 days when the period of low air content was not >14 days. At the highest light intensity the recovery of photosynthesis was slower. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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.

Comparative CO2 exchange patterns in mosses from two tundra habitats at Barrow, Alaska

1976 ◽  
Vol 54 (12) ◽  
pp. 1355-1369 ◽  
Author(s):  
Walter C. Oechel ◽  
Nigel J. Collins
Keyword(s):  
Light Intensity ◽  
Water Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Co2 Exchange ◽  
Polar Regions ◽  
Light Intensities ◽  
Matter Production ◽  
Exchange Patterns

The effects of variation in light intensity, temperature, and water content on rates of net photosynthesis and dark respiration have been investigated in two common tundra mosses, Polytrichum alpinum from drier habitats and Calliergon sarmentosum from wetter habitats at Barrow, Alaska. Optimum temperatures for net photosynthesis of 10–15 °C for both species and saturating light intensities (photosynthetically active radiation (PhAR), 400–700 nm) of about 0.12 cal cm−2 min−1 for P. alpinum and 0.15 cal cm−2 min−1 for C. sarmentosum correlate well with measurements of light intensity and moss tissue temperatures made over the season at the collection site. It is suggested that depressions in net photosynthetic rates around midday might be caused by supraoptimal temperatures and possibly supraoptimal light intensities. Calliergon sarmentosum, a semiaquatic species required a higher water content (about 450% dry weight) than P. alpinum (about 200%) to reach maximal rates of net photosynthesis. Mean maximal rates of net photosynthesis ranged from about 2.6 to 4.4 mg CO2 g−1 dry weight h−1 for P. alpinum and from about 1.5 to 3.0 mg CO2 g−1 dry weight h−1 for C. sarmentosum. Predictions of net annual production have been made for both species. Predicted levels of 171 g C m−2 per 50-day season for C. sarmentosum compare well with results obtained for species of similar growth form elsewhere in polar regions. For P. alpinum the predicted level of 38.5 g C m−2 per 50-day season compares with observed dry matter production at the same site of 43 g m−2 per season.

EFFECT OF DIFFERENT SALINITY AND LIGHT INTENSITY ON THE GROWTH OF PORPHYRIDIUM CRUENTUM

2021 ◽  
Vol 8 (18) ◽  
pp. 71-77
Author(s):  
Leyla USLU
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Optical Density ◽  
Dry Matter ◽  
Porphyridium Cruentum ◽  
Laboratory Conditions ◽  
Light Intensities ◽  
Density Values

In the study, Porphyridium cruentum was cultured under laboratory conditions at 20±2°C, 16:8 (light:dark) photoperiod and continuous aeration to different salinity (20‰, 30‰, 40‰) and two different light intensities (37 µmol m-2s-1 photon and 110 µmol m-2s-1 photon) and growth was determined. Dry matter, optical density and chlorophyll a parameter were used to determine growth. The best growth was determined in culture with a salinity of 30‰ at 110 µmol m-2s-1 photon light intensity. In this group, the optical density (OD) was 1.504±0.003 and the dry matter amount was 1.327gl-1. In the case of 37µmol µmol m-2s-1 photon light intensity, the optical density values were found to be similar in groups with 30‰ and 50‰ salinity and were found to be 1.234±0.004 and 1.215±0.002, respectively. The amounts of dry matter were also similar; 1.168gl-1 and 1.159gl-1, respectively. While the lowest growth was in the culture at 37 µmol m-2s-1 photon light intensity and 20‰ salinity. The optical density obtained on the last day of this group was 1.165±0.004 and the dry matter amount was determined as 0.986gl-1. The amount of chlorophyll a was determined in the cultured groups at the best 37 µmol m-2s-1 photon light intensity.

scholarly journals Production of lettuce with brackish water in NFT hydroponic system

2018 ◽  
Vol 39 (3) ◽  
pp. 947 ◽  
Author(s):  
Jucicléia Soares da Silva ◽  
Vital Pedro da Silva Paz ◽  
Tales Miler Soares ◽  
Willian Fernandes de Almeida ◽  
Joseane Pereira Fernandes
Keyword(s):  
Dry Matter ◽  
Fresh Matter ◽  
Reject Water ◽  
Water Demands ◽  
Nutrient Film Technique ◽  
Matter Production ◽  
Local Water ◽  
Groundwater Reserves ◽  
Semi Arid Region ◽  
Semi Arid

Groundwater reserves in the semi-arid regions, which are mostly brackish, could be used to meet local water demands. Hydroponic cultivation is an alternative of rational use of water. Thus, the objective of this work was to evaluate the technical feasibility of using brackish groundwater in the semi-arid region of Bahia and Recôncavo of Bahia for hydroponic production of curly lettuce cv. ‘Verônica’ and purple lettuce cv. ‘Quatro Estações’. The experiment was conducted in a greenhouse in the city of Cruz das Almas, Bahia State, in a randomized block experimental design, composed of seven treatments [T1- public-supply water; T2- water from the well of UFRB; T3- reject water from the well of Cruz das Almas; T4- water from the well of Sapeaçu; T5- reject water from the well of Sapeaçu; T6- reject water from the well of Conceição do Coité and T7- artificially salinated water (NaCl)] and six replicates in an experimental hydroponic structure using the nutrient film technique (NFT). The following variables were analyzed: number of leaves, shoot fresh matter, shoot length, root length, shoot dry matter, and root dry matter. Relative shoot dry matter production in curly lettuce increased by 1, 5, and 2% in the treatments T2, T3, and T4, respectively, whereas in purple lettuce, the increments were 10, 1, and 20%, respectively, for the same treatments. The use of brackish groundwater from the deep tubular wells of the Federal University of Recôncavo da Bahia and Sapeaçu and desalination reject water from the tubular well of Cruz das Almas proved to be technically feasible for hydroponic lettuce production.

Growth kinetics of Marquis wheat. IV. Temperature dependence

1973 ◽  
Vol 51 (4) ◽  
pp. 729-736 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
Plant Growth ◽  
Net Photosynthesis ◽  
Absolute Maximum ◽  
Temperature Optimum ◽  
Differential Growth ◽  
Low Light ◽  
Growth Coefficient ◽  
Light Intensities ◽  
Kinetics Of

Earlier described data from this laboratory were subjected to primary growth analysis. The plants had been grown in constant conditions of light intensity (200 to 2500 ft-c) and temperature (10° to 30 °C) at five different settings each. Multiple temperature optima were revealed and interpreted. The computed maximum plant growth coefficient was highest in value at 25 °C (plant kmL = 0.44 day−1) and secondarily so at 15 °C, but at the experimental light intensities the plant growth coefficient was maximal at 15 °C. The higher temperature optimum was characteristic of roots and "stems" (stem plus leaf sheaths) whose growth coefficients displayed a prominent peak at 25 °C (root kmL ~ 0.8 day−1, "stem" kmL = 0.4 day−1). This optimum was shifted downward with decreasing light intensity until temperature insensitivity was attained at low light intensity. The low-temperature optimum at 15 °C was principally displayed by leaf blades (lamina kmL = 0.47 day−1) whose computed maximum growth coefficient also showed a secondary maximum at 25°, but the 15 °C peak was the only one evident at low light intensities. It was tentatively concluded that the 25 °C temperature optimum was that of net translocation, and that the 15 °C temperature optimum was that of net photosynthesis in which photosynthesis was primarily balanced by photorespiration in wheat. The differential growth of the organs represented their relative sink strengths for attracting growth substrate, as dependent on light intensity and temperature. The availability of photosynthate was considered to be the dominating factor in the kinetics of growth free from inorganic limitations. When there was very little photosynthate the tissues benefited from translocation on a "first come first serve" basis. The high values of kmL pushed the absolute maximum plant growth coefficient, kM, of Marquis wheat toward 0.5 or 50% per day, and the basis of the advantage over previous approximations must be elucidated by further experiments. The computed relative efficiency of the use of photosynthate for growth was temperature dependent, but its value at optimum temperature was similar to previous estimates.

Seed pre-treatment using a derivative of 5-hydroxybenzimidazole (AMBIOL) pre-acclimates carrot seedlings to drought

2002 ◽  
Vol 82 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Lada R. Rajasekaran ◽  
Terence J. Blake
Keyword(s):  
Root Growth ◽  
Dry Matter ◽  
Net Photosynthesis ◽  
Membrane Capacitance ◽  
Dry Matter Production ◽  
Pressure Potential ◽  
Drought Acclimation ◽  
Matter Production ◽  
Xylem Pressure Potential ◽  
Pre Treatment

The possibility that AMBIOL, a derivative of 5-hydroxybenzimidazole, may promote drought acclimation of carrot seedlings was studied. Carrot seeds were pre-treated by soaking in AMBIOL solutions of 0, 0.1, 1 or 10 mg L–1 for 24 h and germinated. Fifteen-day-old seedlings were exposed to a 7-d drought by withholding water until soil moisture content declined to one-third of the initial values. Drought caused a significant reduction in xylem pressure potential, elongation growth, leaf area expansion, root growth and dry matter production. Membrane capacitance, net photosynthesis, stomatal conductance, transpiration and water use efficiency all declined in all plants under drought. However, seed pre-treatment using AMBIOL 0.1 and 10 mg L–1 completely alleviated the drought-induced reduction in shoot dry matter production. Seed preconditioning using AMBIOL 10 mg L–1 promoted dry matter production, which was 214% higher than in the untreated droughted plants and was even 26% higher than that of the untreated, unstressed controls. AMBIOL appeared to have induced drought acclimation through root adjustments that enhanced root growth, possibly supplying root-derived essential factors. Key words: Acclimation, antioxidant, carrot, drought, dry matter production, 5-hydroxybenzimidazole, growth, membrane capacitance

scholarly journals pengaruh pupuk organik cair genetika plus dan jarak tanam yang berbeda terhadap pertumbuhan dan produksi biomas rumput gajah (pennisetum purpureum)

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Abdul Karim Madina
Keyword(s):  
Plant Height ◽  
Biomass Production ◽  
Leaf Blade ◽  
Dry Matter ◽  
Organic Fertilizer ◽  
Pennisetum Purpureum ◽  
Fertilizer Treatment ◽  
Plant Spacing ◽  
Fresh Matter ◽  
Matter Production

ABSTRACTAbdul Karim Madina. 2018. The Effect of different Levels of Liquid Organic Fertilizer of Genetika Plus and different Spacing on Growth and Production of Elephantgrass Biomass (Pennisetum purpureum). Supervised by Muhammad Mukhtar as main supervised and Musrifah Nusi as vice supervised.The purpose of this research was to determine the effect of the level of liquid organic fertilizer (LOF) of Genetika Plus and different spacing on the growth and production of elephantgrass biomass (Pennisetum purpureum). This research was conducted in Tamboo Sub-District Tilongkabila, Bone Bolango District, from April to June 2018. The method used in this study is Factorial RAL with two factors. Data were analyzed using analysis of varian. The results showed that under fertilizer treatment and plant spacing had a significantly effect on the growth and production of biomass. The highest plant height was obtained in R3K2 (397 cm) and the lowest in R0K3 (210 cm), the highest tillering production was in R3K3 (7.5) and the lowest was in R0K1 (3.5). Whereas biomass production, the highest in fresh matter weight was obtained in R3K1 (29,076) and the lowest in R0K3 (1,638), the highest leaf blade percentage obtained in R3K1 (38,519) and the lowest in R0K1 (14), the highest dry matter weight was obtained in R3K1 (494) and lowest in R0K3 (27.75). Based on the research, the level of genetics plus liquid organic fertilizer (LOF) and plant spacing has a significantly effected on the growth of elephant grass (Pennisetum purpureum) on plant height, fresh matter production, leaf blade percentage, dry matter production and number of tillers.Key words: Biomass production, elephantgrass, Genetika plus fertilyzer, plant spacing

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