scholarly journals Differential Growth Responses of Wheat Seedlings to Elevated CO2

2018 ◽  
Vol 10 (3) ◽  
pp. 400-409 ◽  
Author(s):  
Hamid Reza ESHGHIZADEH ◽  
Morteza ZAHEDI ◽  
Samaneh MOHAMMADI

Intraspecific variations in wheat growth responses to elevated CO2 was evaluated using 20 Iranian bread wheat (Triticum aestivum L.) cultivars. The plants were grown in the modified Hoagland nutrient solution at a greenhouse until 35 days of age using two levels of CO2 (~380 and 700 µmol mol–1). The shoot and root dry weights of the wheat cultivars exhibited average enhancements of 17% and 36%, respectively, under elevated CO2. This increase was associated with higher levels of chlorophyll a (25%), chlorophyll b (21%), carotenoid (30%), leaf area (54%) and plant height (49.9%). The leaf area (r = 0.69**), shoot N content (r = 0.62**), plant height (r = 0.60**) and root volume (r = 0.53*) were found to have important roles in dry matter accumulation of tested wheat cultivars under elevated CO2 concentration. However, responses to elevated CO2 were considerably cultivar-dependent. Based on the stress susceptibility index (SSI) and stress tolerance index (STI), the wheat cultivars exhibiting the best response to elevated CO2 content were ‘Sistan’, ‘Navid’, ‘Shiraz’, ‘Sepahan’ and ‘Bahar’, while the ones with poor responses were ‘Omid’, ‘Marun’, ‘Sorkhtokhm’ and ‘Tajan’. The findings from the present experiment showed significant variation among the Iranian wheat cultivars in terms of their responses to elevated air CO2, providing the opportunity to select the most efficient ones for breeding purposes.

2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 735-743
Author(s):  
M.N.L. Wahidah ◽  
◽  
M.S. Nizam ◽  
C.M.Z. Che Radziah ◽  
W.A. Wan Juliana ◽  
...  

Aim: To determine the growth responses of two peat swamp forest species, Shorea platycarpa, a shade-tolerant slow-growing species and Macaranga pruinosa, a light-demanding fast-growing species under elevated atmospheric CO2 concentration. Methodology: The saplings of both species were grown in a shade house at ambient (400±50 µmol mol-1) and in an open roof ventilation greenhouse at elevated atmospheric CO2 concentration 800±50 µmol mol-1 for seven months. The temperature in both environments ranged between 25-33°C with 55–60% sunlight transmittance and the saplings were thoroughly watered twice a day. Plants growth measurements were estimated at frequent intervals. Saplings biomass characteristics were examined using destructive methods after seven months of treatment and non-destructive method was used for determination of leaf area. Results: Elevated CO2 enhanced all the growth characteristics in M. pruinosa with a significant increase was observed particularly on both height and diameter relative growth rate and biomass characteristics. The height relative growth rate and leaf area were significantly reduced under elevated CO2 in S. platycarpa but did not affect the shoot or root diameter and biomass significantly. A positive correlation (r =0.77, p>0.05) between stem biomass and basal diameter for plants under elevated CO2 was recorded for M. pruinosa, but not in S. platycarpa. Both species showed negative correlation (S. platycarpa; r = -0.53, M. pruinosa; r = -0.46, p>0.05) between stem growth and stem biomass at elevated CO2. Interpretation: These results unveiled profound effects of elevated CO2 on the growth of light-demanding species M. pruinosa, while shade-tolerant species S. platycarpa was not relatively affected by elevated CO2. This underscored the necessity to analyse different species performance to elevated CO2, thereby improving the ability to predict tropical swamp forest ecosystem responses to rising CO2.


1992 ◽  
Vol 40 (5) ◽  
pp. 457 ◽  
Author(s):  
SC Wong ◽  
PE Kriedemann ◽  
GD Farquhar

Four eucalypt species were selected to represent two ecologically disparate groups which would be expected to contrast in seedling vigour and in the nature of growth responses to CO2 × nitrogen supply. Eucalyptus camaldulensis and E. cypellocarpa were taken as examples of fast-growing species with a wide distribution, that develop into large trees. By contrast, E. pauciflora and E. pulverulenta become smaller trees, and show a more limited distribution. Seedlings were established in pots (5 L) of a loamy soil and supplied with nutrient solution containing either 1.2 or 6.0 mM NO3- in both ambient (33 Pa) and CO2-enriched (66 Pa) greenhouses. Analysis of growth response to treatments (2 × 2 factorial) was based on destructive harvest of plants sampled on four occasions over 84 days for E. carnaldulensis and E. cypellocarpa, and 100 days for E. pulverulenta and E. pauciflora. A positive CO2 × N interaction on plant dry mass and leaf area was expressed in all species throughout the study period. In E. carnaldulensis and E. cypellocarpa, plant mass was doubled by high N at 33 Pa CO2, compared with a three to four-fold increase at 66 Pa to reach 34g by final harvest. In E. pulverulenta and E. pauciflora, slower growth resulted in about 50% less mass at a given age, but relative increases due to CO2 and N were of a similar order. A distinction can be made between N and CO2 effects on growth processes as follows. When trees were grown on low N, elevated CO2 increased nitrogen-use efficiency (NUE) at both leaf and whole plant levels. On high N, leaf NUE was increased in E. camaldulensis and E. cypellocarpa, but decreased in E. pulverulenta and E. pauciflora. Whole plant NUE showed no consistent response to elevated CO2 when plants were supplied high N. Net assimilation rate (NAR) was increased by elevated CO2 in all species on either N treatment. Moreover, high N increased NAR under either CO2 treatment in all species. There was a positive N × CO2 interaction on NAR in E. carnaldulensis and E. cypellocarpa, but not in E. pulverulenta and E. pauciflora. Growth indices for E. carnaldulensis and E. cypellocarpa species, and especially E. carnaldulensis, generally exceeded those for E. pulverulenta and E. pauciflora in terms of NAR, leaf NUE, N-enhancement of CO2 effects on leaf area and biomass, and non-structural carbohydrate content of foliage.


2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429


Author(s):  
Rupinder Kaur Jassal ◽  
Harmeet Singh

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016 to study the effect of priming, different seed rate on growth and seed yield of soybean planted under bed and flat method. The study was planned in factorial split plot design, keeping two planting techniques (flat sowing and bed sowing) and two seed priming treatments ( non primed seeds and 100 ppm GA3 primed seeds) in main plot and three seed levels ( 50, 62.5 and 75 kg ha-1) in sub plot. The objective of the study was to evaluate the effect of seed priming on growth and productivity under different planting techniques with the use of varying seed rates. The results revealed that growth attributes viz. emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) was significantly higher under bed planting technique as compared to flat sowing method. The pooled seed yield was increased by 15.6 % in bed planted soybean crop as compared to flat planted crop. Soybean seeds primed with 100 ppm GA3 recorded significant results in all the growth parameters. Primed seed recorded increase in yield 15.3 % than non primed seeds. Seed rate of 62.5 kg ha-1 recorded significantly higher emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) which was statistically similar in results with 75 kg ha-1 seed rate in both the two years. Pooled seed yield of 62.5 kg ha-1seed rate was 4.61 % higher than 75 kg ha-1 and 12.6 % than 50 kg ha-1 seed rate.


2021 ◽  
Vol 2 (2) ◽  
pp. 70-75
Author(s):  
Burhanuddin Wiqar ◽  
Mohammad Safar Noori ◽  
Sayed Younos Amini

The yield loss as a result of weed infestation is a major problem in maize fields. Hence, this research meant to examine the impacts of weed chemical control on maize growth and yield. The design of experiment was randomized complete block, and comprised 10 treatments viz., T1 (Control, weedy check), T2 (Weed free), T3 (Atrazine 1.5 kg ha-1 pre-emergence), T4 (Atrazine 750 g ha-1 + Pendimethalin 750 ml ha-1 pre-emergence), T5 (Atrazine 1.5 kg ha-1 followed by 2,4-D amine 0.4 kg ha-1 at 25 days after sowing as Post-emergence), T6 (Halosulfuron 67 g ha-1 at 25 DAS), T7 (Atrazine 1.5 kg ha-1 pre-emergence followed by Halosulfuron 90 g ha-1 25 days after sowing), T8 (Tembotrione 120 g ha-1 Post-emergence at 25 days after sowing), T9 (Pendimethalin 1000 ml ha-1 pre-rise fb Atrazine 750 g ha-1 + 2,4-D amine 0.4 kg ha-1 at 25 days after sowing as Post-emergence) and T10 (Atrazine 1.5 kg ha-1 pre-emergence followed by Tembotrione 120 g ha-1 Post-emergence at 25 days after sowing) with 3 replicates. The results showed that among other treatments, T10 recorded highest number of kernels per row (36.18), number of kernel cob-1 (499.12) and kernel weight cob-1 (136.97 g). A higher plant height (172.19 cm), leaf area (396.6 cm2 plant-1), dry matter accumulation (211.37 g plant-1), kernel yield (6.7 t ha-1) and stover yield (11.6 t ha-1) were found with weed free check plot which is on par with T10 treatment which brought about a higher value of plant height (162.93 cm), dry weight accumulation (205.7 g plant-1), leaf area (384.3 cm2 plant-1), kernel yield (6.5 t ha-1) and stover yield (11.4 t ha-1). In the meantime, T9 treatment reasonably increased kernel yield (6.2 t ha-1) and stover yield (11.0 t ha-1). It shows that application of herbicides as pre-emergence followed by post-emergence, such as T10 treatment could be a good method for weed control in maize fields.


Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 509
Author(s):  
Tejaswini C. Rangaswamy ◽  
Shankarappa Sridhara ◽  
Konapura Nagaraja Manoj ◽  
Pradeep Gopakkali ◽  
Nandini Ramesh ◽  
...  

Elevated carbon dioxide (EC) can increase the growth and development of different C3 fruit crops, which may further increase the nutrient demand by the accumulated biomass. In this context, the current investigation was conceptualized to evaluate the growth performance and nutrient uptake by tomato plants under elevated CO2 (EC700 and EC550 ppm) and temperature (+2 °C) in comparison to ambient conditions. Significant improvement in the growth indicating parameters like leaf area, leaf area index, leaf area duration and crop growth rate were measured at EC700 and EC550 at different stages of crop growth. Further, broader and thicker leaves of plants under EC700 and EC550 have intercepted higher radiation by almost 11% more than open field plants. Conversely, elevated temperature (+2 °C) had negative influence on crop growth and intercepted almost 7% lower radiation over plants under ambient conditions. Interestingly, earliness of phenophases viz., branch initiation (3.0 days), flower initiation (4.14 days), fruit initiation (4.07 days) and fruit maturation (7.60 days) were observed at EC700 + 2 °C, but it was statistically on par with EC700 and EC550 + 2 °C. Irrespective of the plant parts and growth stages, plants under EC700 and EC550 have showed significantly higher nutrient uptake due to higher root biomass. At EC700, the tune of increase in total nitrogen, phosphorus and potassium uptake was almost 134%, 126% and 135%, respectively compared to open field crop. This indicates higher nutrient demand by the crop under elevated CO2 levels because of higher dry matter accumulation and radiation interception. Thus, nutrient application is needed to be monitored at different growth stages as per the crop needs.


2020 ◽  
Vol 9 (11) ◽  
pp. e2509119677
Author(s):  
Francisco de Sales Oliveira Filho ◽  
Francisco Hevilásio Freire Pereira ◽  
Ewerton Gonçalves de Abrantes ◽  
Pedro Alves dos Santos ◽  
Carlos Alberto Lins Casimiro ◽  
...  

The aim of this study was to evaluate the physiological and growth responses of watermelon under application of NPK rates using different proportions of mineral and organic fertilizers. The experiment was taken place in an area located at the Federal University of Campina Grande (UFCG), Campus Pombal - PB (6º48'16'' S and 37º49'15'' W), during the period from June to September 2013. The treatments consisted of three nutrient concentrations of N, P and K (50, 100 and 150% of NPK recommendation for watermelon) and five proportions of mineral and organic fertilizer (100/0, 75/25, 50/50, 25/75 to 0/100). The design was a randomized block in factorial scheme 3 x 5, with four replications. The amount of 100 % was the corresponding NPK 120 kg ha-1, respectively, for N, P and K. They were evaluated: gas exchange, leaf dry matter, stem, fruit and leaf area. The concentration of 150 % of the recommended NPK to the culture of watermelon was the most effective in increasing the physiological characteristics and dry matter accumulation in stem, leaf, fruit, and leaf area. The combined application of mineral and organic fertilizer provides equivalent photosynthetic rate isolated application of mineral fertilizer with an 50/50 ratio the most effective for this variable. The proportions 75/25 and 50/50 were the most efficient in dry matter accumulation in watermelon.


1994 ◽  
Vol 1 (3) ◽  
pp. 199-206 ◽  
Author(s):  
F. Kamura ◽  
S.L. Albrecht ◽  
J.T. Baker ◽  
L.H. Allen ◽  
K.T. Shanmugam

1998 ◽  
Vol 12 (3) ◽  
pp. 515-521 ◽  
Author(s):  
Michael J. Horak ◽  
Zhuping Gao ◽  
Dallas E. Peterson ◽  
Larry D. Maddux

Little is known about the biology and control of hophornbeam copperleaf, a weed of increasing importance in the Midwest. More than 2 wk of cold stratification and a 0.2% KNO3solution increased germination of hophornbeam copperleaf. Germination at constant 30 C was 47% and alternating 30/20 C was 65%. Scarification did not increase hophornbeam copperleaf germination. Within the first 600 growing degree days after soybean planting, plant height, leaf area, and dry matter accumulation of hophornbeam copperleaf grown in soybean and alone were similar. Subsequently, leaf area and dry matter accumulation of hophornbeam copperleaf grown alone were greater than of those grown in soybean. In contrast, plant height of hophornbeam copperleaf grown in soybean was greater than when grown alone. Hophornbeam copperleaf grown alone produced up to 12 510 seeds/plant, whereas hophornbeam copperleaf grown with soybean produced 980 seeds/plant. Of 13 postemergent herbicides evaluated on hophornbeam copperleaf in soybean, only lactofen, acifluorfen, and fomesafen controlled 80% or more. Lactofen at 210 g ai/ha consistently controlled more than 95% of the hophornbeam copperleaf.


Sign in / Sign up

Export Citation Format

Share Document