scholarly journals The effect on the growth of Lemna minor of alternating periods of light and darkness of equal length

1938 ◽  
Vol 125 (838) ◽  
pp. 115-123 ◽  
Keyword(s):  
Growth Rate ◽  
Lemna Minor ◽  
Stomatal Closure ◽  
Continuous Light ◽  
Dry Weight ◽  
Culture Solution ◽  
Single Individual ◽  
Lighting Conditions ◽  
Net Assimilation ◽  
Total Dry Weight

Garner and Allard (1931) showed that plants grown in alternating light and dark periods of equal duration respond differently according to the length of the period. They found that the growth of Cosmos sulphureus, for example, was progressively poorer as the alternating periods decreased from 12 hr. to 1 min., after which it improved rapidly so that at 5 sec. intermittency the plants were of fairly normal appearance, i.e. like those in 12 hr. alternations. No measurements of these effects however were made. Portsmouth (1937) carried out similar experiments with cucumber plants, and has shown that the increase in total dry weight is greatest in continuous light, only slightly less in 12 hr. alternations and considerably less in 1 min. alternations. He suggests that the effects observed were related to carbohydrate deficiency occasioned by a falling net assimilation rate and partial closure of the stomata at 1 min. alternations. Gregory and Pearse (1937) have shown that short alternating light and dark periods are accompanied by a closing of the stomata in Pelargonium , and here again the effect was at a maximum with intermittencies of about 1 min. duration. In view of the above results it was decided to repeat and extend the growth-rate determinations with Lemna minor , which is simple in structure and is eminently suitable for experimental work under laboratory conditions. It had also the advantage, as its stomatal opening does not change, that should results similar to those of Garner and Allard, and Portsmouth, be obtained it would be possible to assess the value of stomatal closure at rapid intermittencies on growth rate. 2. Experimental procedure Two different stocks of Lemna were employed, one, coming originally from the Chelsea Physic Garden, had been used previously in this de-partment, while the other was a fresh stock obtained from Sutton. Each stock was established in the first instance from a single individual. In all cases colonies were grown under 12 hr. alternating light and darkness for 14 days before being placed under the lighting conditions in which their growth rate was to be measured. Apart from the light factor all environmental conditions were the same during the preliminary 14 days as when measurements were being made. The plants were grown in a culture solution made up as follows: CaH 4 (PO 4 ) 2 . H 2 O 0·100 g., KNO 3 0·800 g., MgSO 4 . 7H 2 O 0·25 g., FeCl 3 0·002g., distilled water 1000 ml. In some cases the water used was condensed on glass, in others on copper. The culture solution was changed only when the plants were being measured; it was not aerated but always shaken up with air immediately before being used. The solution was made up in amounts of 2 litres, but as the number of colonies to be supplied varied from time to time the several lots lasted for different periods.

scholarly journals Growth analysis in chard plants (Beta vulgaris L. Cicla, cv. 'Pencas Blancas') exposed to different light quality

2014 ◽  
Vol 32 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fánor Casierra-Posada ◽  
Esteban Zapata-Casierra ◽  
Daniel A. Chaparro-Chaparro
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Light Quality ◽  
Dry Weight ◽  
Dry Mass ◽  
Dry Matter Partitioning ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Total Dry Weight

To determine the effects of light quality on the growth indices of plants, Pencas Blancas cultivar chard plantlets were grown for 2 months under five different light treatments, obtained by filtering sunlight through colored polyethylene films. The treatments included: red, blue, green, yellow and transparent cover colors. A transparent cover (white light) was used as the control. The colored covers affected the plant growth. The plants grown under the yellow cover presented a better behavior with regards to growth, taken as: total dry weight per plant, leaf area, specific leaf area, absolute growth rate, relative growth rate, harvestable dry matter and root to shoot ratio. The dry matter partitioning in the leaves and roots was affected by the light quality, but not in the petioles, with a higher accumulation of dry mass in the leaves of plants grown under the yellow cover. As a consequence of the enhanced leaf area in the plants under the yellow cover, they also had the highest water uptake. On the other hand, the highest net assimilation rate value was found in plants grown under the transparent cover. These results open up the possibility of using yellow colored cover in leafy green vegetables, especially in chard plants grown under controlled conditions.

scholarly journals The effect of high iron doses (Fe2+) on the growth of broccoli plants (Brassica oleracea var. Italica)

2014 ◽  
Vol 32 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Jaime E. Peña-Olmos ◽  
Fánor Casierra Posada ◽  
Misael A. Olmos-Cubides
Keyword(s):  
Growth Rate ◽  
Brassica Oleracea ◽  
Dry Weight ◽  
Dry Mass ◽  
Iron Sulfate ◽  
Relative Growth ◽  
Excess Iron ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Total Dry Weight

Tests were carried out under greenhouse conditions in Tunja (Colombia) in order to evaluate the effect of Fe2+ toxicity on the growth of broccoli plants. 'Legacy' hybrid Brassica oleracea var. Italica plantlets were grown in glass containers with a nutritive solution. Iron sulfate was added to the substrate in order to produce excess iron at concentrations of 100 and 200 mg L-1; a control without iron sulfate applications was used. The following evaluations were made: leaf area, total dry weight of the plants, distribution of dry mass (DM) in the different organs, absolute growth rate, relative growth rate, net assimilation rate and the root:shoot ratio. The total DM decreased drastically in the plants subjected to excess Fe2+, the growth indices progressively decreased with increases in the Fe2+ concentrations in the substrate and the distribution of DM in the organs varied as a function of the needs of the plants, with 15.85 and 11.10% less DM in the roots of the plants subjected to Fe2+ than in the control plants, at 100 and 250 mg L-1, respectively.

Effects of Temperature and CO2Concentration on the Growth of Cotton (Gossypium hirsutum), Spurred Anoda (Anoda cristata), and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Short Term ◽  
Leaf Weight ◽  
Matter Production ◽  
Total Plant ◽  
Net Assimilation ◽  
Total Dry Weight

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.

EFFECT OF SOLID AND LIQUID ORGANIC FERTILIZER ON GROWTH, YIELD AND YIELD COMPONENTS OF ROSSELLE (Hibiscus sabdariffa L.) IN THE NIGERIAN SAVANNAH

2021 ◽  
Vol 5 (2) ◽  
pp. 428-439
Author(s):  
K. M. Ladan ◽  
M. G. Abubakar ◽  
J. Suleiman
Keyword(s):  
Growth Rate ◽  
Plant Height ◽  
Seed Weight ◽  
Organic Fertilizer ◽  
Poultry Manure ◽  
Dry Weight ◽  
Assimilation Rate ◽  
Area Index ◽  
Net Assimilation ◽  
100 Seed Weight

The Study was conducted to evaluate the effect of solid and liquid organic fertilizer on growth and yield of rosselle in 2016 cropping season at Institute of Agricultural Reserve Zaria, Samaru (11011’N 07038E and 686m) and Institute of Horticultural Research Farm Bagauda (12000’N 8031”Em 488m) in Northern Guinea Savannah and Sudan Savannah Ecological Zones of above sea level Nigeria. Treatments consisted of four levels of solid poultry manure (0.0, 1.0, 2.0 and 3.0) tons/ha and five levels of liquid organic manure from Grand Total Organic Fertilizer Limited (0.0, 0.5, 1.0, 1.5 and 2.9) litres/ha, which were factorially combined in a randomized complete block design (RCBD) and replicated three times. Data on growth parameter were collected on plant height (cm), plant dry weight (g), leaf Area index crop growth rate (CGR) Relative Growth Rate (RGR) and Net assimilation rate (NAR) while data on yield parameters like number of calyx per pant, 100 seed weight (g) and  calyx yield per hectare kg/ha were collected. Results showed that plant height, plant dry weight(g), 100 seed weight(g) and calyx dry yield kg/ha had a significant increase with application of 2.0 litres/ha of liquid fertilizer than other rates. While application of solid poultry manure at 3.0ton/ha significantly increases plant height, net assimilation rate, leaf area index and calyx dry weight when compared with other rates. From the results obtained, the combination of 2.0 litres/ha liquid organic fertilizer and 3.0 ton/ha solid poultry manure produce the highest calyx yield at both location.

scholarly journals Influence of Soil Amendment on the Relative Growth Rate and Net Assimilation Rate of Phaseolus vulgaris and Vigna aconitifolia

2020 ◽  
pp. 1-13
Author(s):  
E. A. Effa ◽  
A. A. J. Mofunanya ◽  
B. A. Ngele
Keyword(s):  
Growth Rate ◽  
Phaseolus Vulgaris ◽  
Relative Growth Rate ◽  
Soil Amendment ◽  
Dry Weight ◽  
Organic Manure ◽  
Assimilation Rate ◽  
Vigna Aconitifolia ◽  
Relative Growth ◽  
Net Assimilation

Background: Soil pH is one of the most important factors that contribute to crop growth and productivity. The present research was designed to assess the influence of soil amendment using organic manure and agricultural lime on the relative growth rate (RGR) and net assimilation rate (NAR) of Phaseolus vulgaris and Vigna aconitifolia grown on soils from different locations. Methodology: The three locations were: Akamkpa, Calabar Municipality and Odukpani. The pH for the three soil locations were 4.0, 7.0 and 9.0, respectively. The treatments were; control (0 g), OM1 (100 g organic manure), OM2 (200 g organic manure), AL1 (100 g agricultural lime), AL2 (200 g agricultural lime), OM1 + AL1 (50 g organic manure + 50 g agricultural lime) and OM2 +AL2 (100 g organic manure and 100 g agricultural lime). Results: Results obtained on the RGR of the leaf dry weight of P. vulgaris treated with OM2 was the highest (0.50 g/wk) followed by OM1 (0.41 g/wk). OM1 + AL1 had the highest RGR of the stem dry weight of P. vulgaris grown on soil from Calabar Municipality. In the RGR of the root dry weight, OM2 had the highest mean value in both plants grown on Akamkpa soil. Results obtained at 4 weeks after planting (WAP) revealed that there was significant (P<0.05) increase in NAR of plants grown on soil from Akamkpa. The highest NAR was obtained for V. aconitifolia treated with OM2 (0.0447 g/wk) followed by OM2 + AL2 (0.0057 g/wk) for both V. aconitifolia and P. vulgaris. P. vulgaris grown on Akamkpa and Odukpani soils treated with AL2 (0.0032 g/wk), OM1 + AL1 (0.0041 g/wk) and OM2+ AL2 (0.0062 g/wk) had the highest NAR at 8 WAP. Conclusion: The RGR and NAR of the two bean varieties were improved following treatments with organic manure and agricultural lime.

scholarly journals Fitness Cost of Imazamox Resistance in Wild Poinsettia (Euphorbia heterophylla L.)

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Weight ◽  
Area Ratio ◽  
Fitness Cost ◽  
Seed Plant ◽  
Growth Indices ◽  
Relative Growth ◽  
Net Assimilation

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.

Competition, Growth Rate, and CO2Fixation in Triazine-Susceptible and -Resistant Smooth Pigweed (Amaranthus hybridus)

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 438-444 ◽  
Author(s):  
William H. Ahrens ◽  
E. W. Stoller
Keyword(s):  
Growth Rate ◽  
Dry Weight ◽  
Dry Matter Accumulation ◽  
Lower Growth ◽  
Amaranthus Hybridus ◽  
Relative Growth ◽  
Lower Growth Rate ◽  
Net Assimilation ◽  
Synthetic Capacity ◽  
Smooth Pigweed

Triazine-susceptible (S) and -resistant (R) biotypes of smooth pigweed (Amaranthus hybridusL.) were grown in the field under competitive conditions at varying initial proportions of S and R plants. R plants were less competitive than S plants as measured by accumulation of total above-ground dry weight and seed dry weight. S and R plants were also grown in the field under non-competitive conditions at 100, 40, and 10% light. Growth rate at 10% light did not differ between S and R plants. At the two higher light intensities, dry-matter accumulation 11 weeks after seeding was about 40% less in the R plants. At 100% light, relative growth rate and net assimilation rate were lower in the R plants by about 3.5 and 19%, respectively. The light- and CO2-saturated rates of CO2fixation in intact leaves of glasshouse-grown R plants were 20% less than those in S plants. An apparent 10 and 20% greater number of chlorophyll molecules per photosystem II reaction center in R plants (as compared with S plants) grown in the field at 40 and 100% light, respectively, did not explain differences between the S and R biotypes in photo synthetic capacity. The S and R plants did not differ in specific leaf weight or chlorophyll content on a leaf-area basis. Lower growth rate of R plants may be responsible for inferior competitive ability of R biotypes and could be the result of an impaired photosynthetic capacity.

scholarly journals Variation Between Cut Chrysanthemum Cultivars in Response to Suboptimal Temperature

2007 ◽  
Vol 132 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Anke van der Ploeg ◽  
Ranathunga J.K.N. Kularathne ◽  
Susana M.P. Carvalho ◽  
Ep Heuvelink
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Temperature Response ◽  
Dry Weight ◽  
Stem Length ◽  
Long Day ◽  
Cultivation Period ◽  
Optimum Response ◽  
Total Dry Weight ◽  
Response To Temperature

To breed for more energy-efficient cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivars it is important to know the variation of the temperature response existing in modern cultivars. In a greenhouse experiment with 25 chrysanthemum cultivars, a significant variation was observed in temperature response (16 °C or 20 °C) for reaction time, total dry weight produced, stem length, and flower size and number. To study this genetic variation in temperature response over a larger range of temperatures (15 °C to 24 °C), four contrasting cultivars (Annecy, Delianne, Reagan, and Supernova) were selected in a second experiment. Furthermore, a third experiment was performed in which the cultivation period was split into three phases and the influence of temperature in each of these phases was studied for the four selected cultivars. Dry weight production in all cultivars was very sensitive to temperature during the long day period. Relative growth rate showed an optimum response to temperature, with the optimum around 24 °C. Net assimilation rate also showed an optimum response to temperature, whereas leaf area ratio increased linearly with temperature. Compared with these temperature effects during the long day, the effect of temperature on absolute growth rate during the short day was, depending on the cultivar, relatively small or even absent. The reaction time, on the other hand, was very temperature sensitive, showing an optimum that was cultivar dependent. The temperature response of the total dry weight production during the whole cultivation period was, therefore, very cultivar dependent. Furthermore, depending on the cultivar, stem length increased with temperature, especially during long day, as a result of both increasing internode number and average internode length. The response of both flower size and number to temperature was also highly cultivar specific. The possibilities of using this genetic variation for breeding are discussed.

Development of yield in two grain-sorghum hybrids. I. Dry weight and carbon-14 studies

1982 ◽  
Vol 33 (6) ◽  
pp. 1009 ◽  
Author(s):  
RJ Chamberlin ◽  
GL Wilson
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Growth And Development ◽  
Dry Weight ◽  
Grain Sorghum ◽  
Carbon 14 ◽  
Biological Yield ◽  
Total Dry Weight ◽  
Weight Data

Growth and development of two grain-sorghum hybrids (De Kalb E57 and Texas 610) were examined under glasshouse conditions by sequential harvesting and the use of I4C. The grain yield per plant of Texas 610 was higher than that of E57, with higher total biological yield and similar harvest indices. The contribution to grain weight at maturity, of carbon assimilated prior to anthesis, was about 10% for each hybrid. The leaves were the main source of this material. After anthesis, dry weight data indicated that temporary storage of assimilates before retranslocation to the grain was of greater importance in Texas 610 than E57. This storage was largely in the leaves (including sheaths), upper internodes, and roots. A high grain-growth rate was maintained for longer by Texas 610 than by E57. Total dry weight production after anthesis in both hybrids was, at all stages examined, more than sufficient to maintain grain growth.

scholarly journals COMPARISON OF GROWTH AND TUBER DEVELOPMENT IN THREE POTATO CULTIVARS WITH DIVERSE CANOPY SIZE

1977 ◽  
Vol 57 (3) ◽  
pp. 797-801 ◽  
Author(s):  
W. B. COLLINS
Keyword(s):  
Growth Rate ◽  
Potato Breeding ◽  
Dry Weight ◽  
Net Assimilation Rate ◽  
Tuber Growth ◽  
Assimilation Rate ◽  
Tuber Development ◽  
Final Yield ◽  
Net Assimilation ◽  
Canopy Size

The basis of differences in tuber and plant development in potato, due to differences in canopy size, was studied by measuring changes in plant dry weight and leaf area throughout the growing season. Differing canopy sizes were obtained by selecting three cultivars from the Canada Potato Breeding Program. These were F57048, Grand Falls, and F62008, which normally produce small, medium and large sized canopies respectively, with similar tuber yields. Differences in total and tuber dry weight through the season were slight compared to differences observed in leaf and stem growth. The branching capacity of the cultivars appeared to be the major determinant of canopy size. In these three cultivars, as canopy size increased, the initial tuber growth rate immediately following tuberization decreased. Thus, in the two smaller cultivars, the early tuber growth rate was more critical in determining final yield than was the case in the large-canopied cultivar, F62008. As expected, the net assimilation rate increased as canopy size decreased. The evidence indicated that the demands of the developing tubers exerted the greatest influence on the net assimilation rate.

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