Effects of Carbon Dioxide Enrichment on the Growth and Morphology of Kudzu (Pueraria lobata)

Weed Science ◽  
1988 ◽  
Vol 36 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Thomas W. Sasek ◽  
Boyd R. Strain

Kudzu (Pueraria lobataOhwi # PUELO) was grown from seeds in controlled-environment chambers at 350, 675, or 1000μl·1−1CO2. Biomass and leaf area production, morphological characteristics, and growth analysis components were determined at 14, 24, 45, and 60 days after emergence. At 60 days, plants grown at 1000μl·1−1CO2had 51% more biomass, 58% longer stems, and 50% more branches than plants grown at 350μl·1−1CO2. Plants grown at 675μl·1−1CO2were intermediate. Growth analysis components indicated that CO2enrichment increased growth by compounding effects due to increased net assimilation rates and increased leaf area duration. Relative growth rates were not significantly affected. The large CO2-induced increase in stem height versus stem diameter is in marked contrast to previously reported responses of woody erect growth forms. Possible ecological implications for competitive abilities are discussed.

Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Andrew C. Seibert ◽  
R. Brent Pearce

Growth and morphological characteristics of four weed and two crop species were analyzed to determine how small-seeded weeds can compete with large-seeded crops despite the initial size disadvantage. Small-seeded weeds had higher relative growth rates because of increased percentages of biomass devoted to leaves. This morphological scheme was achieved primarily through a reduction in the percentage of biomass devoted to roots. Yet, small-seeded weeds were able to develop larger mean plant root lengths as a result of having both roots of smaller diameter and higher rates of root length increase.


1982 ◽  
Vol 30 (3) ◽  
pp. 347 ◽  
Author(s):  
RM Gleadow ◽  
KS Rowan

The clumping of invading seedlings of Pittosporum undulatum Vent. around the butts of established trees is due partly to the site-dependent survival of seedlings. particularly during summer. P. undulatum seedlings were very drought-tolerant when grown at moderately low temperatures (21.4°C day/17.8°C night compared with 27.4°C day/23.9°C night) and in deep shade. Plants droughted at 5°C higher temperatures and higher photon flux densities stopped transpiring and wilted 10-13 days earlier than those droughted under cooler, densely shaded conditions. Well watered seedlings had higher relative growth rates and net assimilation rates when grown under higher temperatures and photon flux densities. Control seedlings were more leafy when grown under low light. as reflected by the specific leaf area, leaf area ratio and root/shoot ratios. The adverse effects of higher photon flux densities and temperatures on the drought tolerance of P. undulatum seedlings support the hypothesis that survlval of invading seedlings in their first year is dependent on the microclimate.


2019 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
N. Nurmuliana ◽  
Muh. Akhsan Akib

AbstractThe growth of jack bean (Canavalia ensiformis L) is affected by genetic and environmental factors.  One of the environmental factors involved is growing space. Growing space related to each plant of areas occupied is stated by the distance between plants. A Research has been conducted as long three months in dry season with average daily temperature of 25 to 31OC on altitude of 25 to 500 meter, to determine the timing of the application of cutback technology based on an analysis of growth of jack bean plants (Canavalia ensiformis L) in different growth spaces.  The research was conducted in the trial form using a randomized block design. Variables of plants growth analysis observed is leaf area index (LAI), leaf area is computed by gravimetric method; net assimilation rate (NAR), and relative growth rate (RGR) is determined based on the dry weight of plants; in all three rooms grew, namely 75 cm x 100 cm (control), 75 cm × 75 cm and 75 cm × 50 cm, each repeated three times. The result shows that the trend of leaf area index increased at net assimilation rate (g-1.cm-2.week-1) and relative growth rate (g-1.g-1.minggu-1) decreasing at the time the plant to the age 8 weeks after planting.  The best time for the application of reduction technology to jack bean plants (Canavalia ensiformis L) in all tested growing spaces, is recommended when plants are between 7 and 8 weeks after planting


1969 ◽  
Vol 49 (4) ◽  
pp. 465-470
Author(s):  
D. B. Wilson ◽  
A. Johnston

Seedlings of a native grass, rough fescue, Festuca scabrella Torr., and of a tame grass, tall fescue, Festuca arundinacea Schreb., were grown in the greenhouse for 10 weeks. Each week 20 plants of each species were destructively harvested for growth analysis. Leaf and tiller numbers and leaf lengths were recorded for an additional 10 plants of each species. Mean net assimilation rates of rough fescue were similar to those of tall fescue, but leaf area ratios were significantly lower. Thus, mean relative growth rates of rough fescue were less than those of tall fescue. Tiller numbers were similar for both species but rough fescue produced fewer leaves. Dry weight of tops of the tame grass produced during the 10-week period was about 17 times that produced by the native grass.


2019 ◽  
Vol 11 (11) ◽  
pp. 214
Author(s):  
Fernando Storniolo Adegas ◽  
Dionísio Luiz Pisa Gazziero ◽  
Alexandre Ferreira da Silva ◽  
Germani Concenço

Sourgrass (Digitaria insularis) is highlighted as one of the most troublesome weeds in Brazilian agriculture. The growth analysis of the species and biotypes with resistance to glyphosate are preponderant to support management strategies. In this way, the aim of this work is to compare the growth of biotypes resistant and susceptible to glyphosate, and to characterize the species growth in field conditions. The greenhouse experiment was installed in randomized blocks design, in factorial scheme 2 × 10, with eight replications. Factor A comprised the biotypes, and factor B the fortnight evaluations. The dry mass of roots, stems, leaves and shoot were assessed, besides leaf area and plant height. From these variables, the relative growth rate, net assimilation rate and leaf area ratio were calculated. For the field experiment, the same variables were assessed and the same parameters were calculated, without distinction on resistant or susceptible biotype. The biotype with resistance to glyphosate did not show adaptative disadvantages compared to the susceptible one. In this way, it is necessary to prevent the entry of resistant biotypes in cropped fields, as once established the area may not naturally return to the initial frequency of susceptible biotypes. Sourgrass shown slow initial growth and dry mass accumulation up to 42 days after emergence, indicating that control of this specie should be performed preferably before this period.


1972 ◽  
Vol 52 (1) ◽  
pp. 13-20 ◽  
Author(s):  
B. R. BUTTERY ◽  
R. I. BUZZELL

Spaced plants of soybean (Glycine max (L.) Merrill) cultivars were subjected to classical growth analysis. Varietal differences in mean net assimilation rate (NAR), relative growth rate (RGR), relative leaf growth rate (RLGR), leaf area ratio (LAR), specific leaf weight (SLW), and shoot/root ratio (S/R) were detected within a group of 21 cultivars grown in three tests over 3 years. Only LAR and SLW differed within another group of 23 cultivars grown in 2 years. Comparisons of cultivars with their parents showed that selection for yield had resulted in increased NAR and SLW, and in decreased LAR, S/R, plant weight, and leaf area. Many of the cultivars were transgressive segregants for higher NAR and SLW and for lower LAR. Phenotypic correlations showed that NAR was highly correlated with SLW and inversely correlated with LAR. SLW might be a useful character for indirect selection of soybean yield.


2016 ◽  
Vol 40 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Saiful Islam ◽  
Nargis Jahan

An investigation was made to see the effect of different concentrations (10, 20, 30 and 40 ppm) of 2, 3, 5- triiodobenzoic acid (TIBA) on leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) of a cultivar of chickpea (Cicer arietinum L.) grown during rabi season of 2015 - 2016. Results revealed that LAI and LAD showed a positive response from flowering stage to maturity (66 - 110 DAS) due to 30 ppm TIBA application with maximum LAI and LAD occurring at the flowering stage. At 66 - 83 and 83 - 97 DAS, CGR was highest with the application of 30 ppm TIBA, while RGR was highest due to 10 ppm TIBA. Peak CGR was recorded at the time of pod setting to pod filling stage (8 - 97) and increased over control by 29.64%. Irrespective of the treatments, NAR was recorded maximum during flowering stage to pod setting (66 - 83 DAS) and thereafter decreased till maturity. At 66 - 83 and 83 - 97 DAS, maximum NAR values were recorded due to 30 ppm TIBA and the increases were 9.09 and 32.69% higher over the control, respectively.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 2, 199-205, 2016


Author(s):  
Mohamed Ewis Abdelaziz ◽  
A. H. Hannfy Ahmed ◽  
R. S. Bekhid ◽  
Robert Pokluda

This work was conducted to study the effect of five NPK fertigation levels on the growth rate of sweet pepper (Capsicum annuum L. cv. Bruyo) grown under the plastic greenhouse using different growth analysis formulas. Leaf area ratio (LAR), specific leaf area (SLA), relative growth rate (RGR) and net assimilation rate (NAR) was evaluated in two periods (60–90 and 90–120 days after transplanting). The mean values of LAR, SLA, RGR and NAR tended to decrease significantly with advancing plant age in both seasons. In general, at the moderate level (34N-42P-29K / plastic house 540 m2) was found the highest significant values of LAR and SLA in the two growth periods. On the other hand, the highest values of NAR were recorded at the plants treated with the lowest NPK fertigation level (17N-21P-15K / plastic house 540 m2). However, increase of NPK fertigation doses to the moderate levels had favorable effects on LAR and SLA of sweet pepper plants.


1970 ◽  
Vol 21 (2) ◽  
pp. 183 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson

A previous study of one grass and one legume at early vegetative stages has been extended to include a further nine species of each. It confirms the superior relative growth rates (RW) of grasses, arising from very high net assimilation rates (EA), in turn dependent on high photosynthetic rates (P). Leaf area ratios (FA) varied over a similar range in both groups. RW values of grasses in the second week after sowing varied from 0.41 to 0.55 gg-1 day-1; for legumes, they were 0.31-0.36. Corresponding EA values were 1.5-1.9 g dm-2 wk-1 in grasses, and 1.1-1.8 in legumes. Within both grasses and legumes, comparisons between species can be made with less certainty. In grasses, variation in FA combined with generally uniform EA values resulted in variable RW values. Both FA and EA varied in the legumes but were usually compensatory, leading to uniformity in RW. Watson and Hayashi's method of separating EA into photosynthetic and respiratory components was used. Differences both between and within grasses and legumes were shown, but there are probably important errors in this technique, particularly where there are discrepancies between light and dark respiration.


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