An analysis of the growth of silver maple and eastern cottonwood seedlings exposed to ozone

1982 ◽  
Vol 12 (2) ◽  
pp. 420-424 ◽  
Author(s):  
K. F. Jensen

Silver maple (Acersaccharinum L.) and eastern cottonwood (Populusdeltoides Bartr.) seedlings were treated with either 0.0, 0.1, 0.2, or 0.3 ppm ozone for 12 h/day for up to 60 consecutive days. Six seedlings were harvested from each treatment at 10-day intervals to construct growth curves for leaf area, leaf weight, and stem plus leaf weight. Relative growth parameters were calculated from these curves. Relative growth rate, relative leaf-area growth rate, and relative leaf-weight growth rate declined with an increase in time and ozone concentration. Net assimilation rate declined with time in both species. Specific leaf area and leaf-area ratio had no consistent trends.

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. M. A. Mondal ◽  
A. B. Puteh ◽  
M. A. Malek ◽  
M. R. Ismail ◽  
M. Y. Rafii ◽  
...  

Growth parameters such as leaf area (LA), total dry mass (TDM) production, crop growth rate (CGR), relative growth rate (RGR), and net assimilation rate (NAR) were compared in six varieties of mungbean under subtropical condition (24°8′ N 90°0′ E) to identify limiting growth characters for the efficient application of physiology breeding for higher yields. Results revealed that a relatively smaller portion of TDM was produced before flower initiation and the bulk of it after anthesis. The maximum CGR was observed during pod filling stage in all the varieties due to maximum leaf area (LA) development at this stage. Two plant characters such as LA and CGR contributed to the higher TDM production. Results indicated that high yielding mungbean varieties should possess larger LA, higher TDM production ability, superior CGR at all growth stages, and high relative growth rate and net assimilation rate at vegetative stage which would result in superior yield components.


HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1262e-1262
Author(s):  
N. Soltani ◽  
A.R. Harmon ◽  
J.L. Anderson

`Crimson Sweet' watermelon plants grown under various mulches and rowcovers were harvested weekly and analyzed for absolute growth rate (AGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA), specific leaf weight (SLW), leaf weight ratio (LWR), leaf area duration (LAD), biomass duration (BMD), and runner growth. Hourly air and soil temperatures were monitored inside the rowcovers. Vispore and Reemay rowcovers generally showed greater mean AGR, LAR, SLA, LAD, and BMD than Agronet black-clear and black mulches. No significant differences in LWR were found between mulched and rowcovered plants. Plants under mulches and rowcovers showed significant increases in AGR, RGR, NAR, LAR, SLA, LAD, and BMD over noncovered (bare ground) plants. Longest runner length was highly correlated with total runner length. Growth analyses depicted decreased growth rate inside the rowcovers during the hottest weeks of the summer, and generally correlated well with the earliness and total yield of the crop.


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6501
Author(s):  
Mohammad Ajlouni ◽  
Audrey Kruse ◽  
Jorge A. Condori-Apfata ◽  
Maria Valderrama Valencia ◽  
Chris Hoagland ◽  
...  

Crop growth analysis is used for the assessment of crop yield potential and stress tolerance. Capturing continuous plant growth has been a goal since the early 20th century; however, this requires a large number of replicates and multiple destructive measurements. The use of machine vision techniques holds promise as a fast, reliable, and non-destructive method to analyze crop growth based on surrogates for plant traits and growth parameters. We used machine vision to infer plant size along with destructive measurements at multiple time points to analyze growth parameters of spring wheat genotypes. We measured side-projected area by machine vision and RGB imaging. Three traits, i.e., biomass (BIO), leaf dry weight (LDW), and leaf area (LA), were measured using low-throughput techniques. However, RGB imaging was used to produce side projected area (SPA) as the high throughput trait. Significant effects of time point and genotype on BIO, LDW, LA, and SPA were observed. SPA was a robust predictor of leaf area, leaf dry weight, and biomass. Relative growth rate estimated using SPA was a robust predictor of the relative growth rate measured using biomass and leaf dry weight. Large numbers of entries can be assessed by this method for genetic mapping projects to produce a continuous growth curve with fewer replicates.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado

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.


2017 ◽  
Vol 43 (1) ◽  
pp. 49-60
Author(s):  
Ferdowsi Noor ◽  
Feroza Hossain ◽  
Umme Ara

A field study was conducted during the Rabi season of 2009-2010 in the research field of Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka. Six levels of GA3, viz. 0, 30, 50, 70, 90 and 110 ppm were sprayed at 18 days after sowing (DAS). GA3 treatments significantly increased plant height than the control plants. GA3 with 30 to 90 ppm significantly increased number of branches and leaves, leaf area, leaf area index (LAI), leaf dry matter and total dry matter at different growth stages. GA3 at 30 to 70 ppm gradually increased crop growth rate (CGR), net assimilation rate (NAR) and relative growth rate (RGR) and declined advanced growth stages. Number of dry pods /plant, number of seeds /pod, 1000 seed weight, fresh fodder, fresh pod, dry seed yield and harvest index also significantly increased. Positive significant correlations were found among growth parameters and as well as yield contributing characters. Asiat. Soc. Bangladesh, Sci. 43(1): 49-60, June 2017


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


Author(s):  
Parthvee Rupsinh Damor ◽  
Arvind D. Patel

Background: Among the pulse crops mungbean is one of the richest sources of protein. There is great loss in the yield of mungbean due to various reasons may be biotic or abiotic constraints. To overcome the yield loss various physiological activities are studied. Physiological activities of the plant are greatly influenced by the source manipulation, plant growth regulators and chemical in mungbean. In correspondence to this, an experiment was conducted to study the physiological parameters in greengram.Methods: A factorial randomized block design in two respective years, i.e. 2016 and 2017 to study the response of source manipulation (nipping, 25% defoliation and 50% defoliation), plant growth regulators (GA3 and NAA at 25 and 50mg/l respectively) and chemical (Thiourea 500 and 1000mg/l) on the physiological parameters like Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and Leaf Area (LA) in greengram at 30, 45, 60 and 75 DAS/harvest at Regional Research Station, Anand Agricultural University, Anand. Result: From the obtained results it can be proposed that the physiological parameters like crop growth rate, relative growth rate and net assimilation rate increased with the increasing phase and decreased at harvesting stage. While leaf area increased significantly at each growth phase. The treatment of nipping M2 was noted significantly higher value for CGR i.e., 8.42, 16.17 and 11.48 g/cm2/day/10, for RGR i.e., 0.544, 2.967 and 1.290 g/day, for NAR i.e., 0.466, 2.959 and 1.484 mg/cm2/day and for LA i.e. 96.87, 218.94, 381.88 and 588.78 cm2. While the treatment S2 GA3 25 mg/l was noted significantly higher value for CGR i.e, 8.60, 16.67 and 11.69 g/cm2/day/10, for RGR i.e., 0.568, 2.938 and 1.202 g/day, for NAR i.e., 0.372, 3.043 and 1.529 mg/cm2/day and for LA i.e., 96.61, 224.75, 382.20 and 580.42 cm2 contributing to the higher seed yield under M2 nipping treatment i.e., (1719.7 kg/ha) and S2 treatment i.e., GA3 25 mg/l (1714.1 kg/ha). Thus, GAM-5 had a better source-sink partitioning efficiency.


1968 ◽  
Vol 48 (3) ◽  
pp. 299-311 ◽  
Author(s):  
C. A. Campbell ◽  
D. W. L. Read

The response of Chinook wheat to light intensity, air temperature and soil moisture stress was studied under controlled environmental conditions in a 3 × 3 × 2 factorial experiment.Increasing day temperature from 21 to 27 °C or night temperature from 13 to 21 °C did not affect tillering, but the plants had shorter, slimmer culms with smaller individual leaves, less total leaf area, and less vegetative and grain dry matter. Temperature changes had little effect on leaf area ratios and their influence on net assimilation rate and relative growth rate was inconsistent. Percent grain protein was increased by temperature.A reduction of light intensity from 17 to 6 cals cm−2hr−1 did not change individual leaf size, but did produce shorter plants with fewer tillers and weak culms. Vegetative, root and grain dry matter were reduced. Shading reduced the translocation of leaf assimilates and lowered the cellulose content of the straw, but increased percent grain protein.Plants developed more tillers at the lower moisture stress, but this difference disappeared by heading time. The lower stress resulted in taller, thicker-stemmed culms with a greater total leaf area, and greater yields of straw and root. The effect of moisture on leaf area ratio was small and its influence on net assimilation rate and relative growth rate was small and inconsistent. Its influence on grain yield varied with temperature; the latter interaction was traced specifically to the influence of moisture stress on seed set. The effect of moisture on percent protein and carbohydrates in grain and on percent cellulose in the straw was inconsistent.


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