Effects of CO2 enrichment and temperature on growth in two C4 weeds, Echinochloa crus-galli and Eleusine indica

1985 ◽  
Vol 63 (9) ◽  
pp. 1495-1499 ◽  
Author(s):  
Catherine Potvin ◽  
Boyd R. Strain

Mathematical growth analyses were carried out on two C4 grasses, Echinochloa crus-galli and Eleusine indica, to test the influence of CO2 enrichment and temperature on growth. Echinochloa populations from Québec, North Carolina, and Mississippi and a single population of Eleusine from Mississippi were grown for 48 days at two CO2 concentrations (350 and 675 μL∙L−1) and three temperature regimes (28:22, 24:18, and 21:15 °C). CO2 enrichment generated an increased root dry weight and induced an earlier development of inflorescences. Net assimilation rate, the only other parameter to respond to CO2 enrichment, was higher for plants grown at high CO2 concentrations during the first harvest interval. Biomass partitioning was affected by temperature. Root dry weight was greater in plants grown at 21:15 °C while more leaf area was produced in warmer temperature regimes. Only plants from Québec maintained normal growth rates under the 21:15 °C regime, suggesting that northern C4 plants are better suited for growth at low temperatures than southern ones.

1985 ◽  
Vol 63 (3) ◽  
pp. 483-487 ◽  
Author(s):  
Catherine Potvin ◽  
Boyd R. Strain

Plants of Echinochloa crus-galli from Québec, North Carolina, and Mississippi and of Eleusine indica from Mississippi were grown under three thermoperiods (28:22, 24:18, 21:15 °C) and two atmospheric CO2 concentrations (350 and 675 μL ∙ L−1). CO2 enrichment induced an increase in net photosynthesis and in dark respiration for all populations. Neither conductance, transpiration, nor the transpiration/photosynthesis ratio were affected by CO2 enrichment. Plants showed higher photosynthetic and dark respiration rates when grown in warm regimes. Stomatal conductance did not vary with growth temperature. Cool-adapted plants from Québec maintained the overall highest net photosynthesis and respiration. Plants originating from warm areas had a weaker acclimation potential to low temperature than those from cool environments.


1981 ◽  
Vol 97 (2) ◽  
pp. 335-339 ◽  
Author(s):  
N. Sionit ◽  
B. R. Strain ◽  
H. Hellmers

SummaryGrowth and yield components of a semi-dwarf spring wheat (Triticum aestivumL., cv. GWO 1809) were determined under three different atmospheric CO2a concentrations (350, 675 and 1000 μ1/1) in controlled environment chambers of the Duke University Phytotron. CO2 enrichment enhanced tiller and head emergence and increased the number of head-producing tillers and the total dry weight of the plants. Total leaf area, stem height and root/shoot ratio of the plants were greater at high CO2concentrations than at low. Net assimilation rate (NAR) increased with increasing CO2concentration and decreased with plant size. There was little effect of CO2enrichment on leaf weight ratio (LWR) and leaf area ratio (LAR) and no significant effect on specific leaf area (SLA). The weight and number of seeds were significantly higher with increasing CO2concentration. The results of this study provide evidence that important changes in plant growth and development may occur during the next century if global CO2enrichment continues. Some of these changes would have important ecological impact in natural and managed ecosystems in the future.


1990 ◽  
Vol 115 (4) ◽  
pp. 525-529 ◽  
Author(s):  
B. Acock ◽  
M.C. Acock ◽  
D. Pasternak

We examined how temperature and stage of vegetative growth affect carbohydrate production and accumulation in Cucumis melo L. `Haogen' grown at various CO2 concentrations ([CO2]). Carbohydrate production was measured by net assimilation rate either on a leaf-area basis (NARa) or a leaf dry-weight basis (NARw); carbohydrate accumulation was measured by leaf starch plus sugar content. Twenty-four- and 35-day-old muskmelon plants were grown for 11 days in artificially lighted cabinets at day/night temperatures of 20/20 or 40/20C and at [CO2] of 300 or 1500 μl·liter-1. NARa and NARw both increased with increasing [CO2], but the CO2 effect was smaller at low temperature, especially for plants at the later stage of vegetative growth. NARw was a better indicator of total dry-weight gain than was NARa. Both suboptimal temperatures and CO2 enrichment caused carbohydrates to accumulate in the leaves at both stages of vegetative growth. NARw was correlated negatively with leaf starch plus sugar content. The rate of decrease in NARw with increasing leaf starch plus sugar content was significantly greater for CO2-enriched plants. Leaf starch plus sugar content >0.03 to 0.04 kg·kg-1 of leaf residual dry weight at the end of a dark period may indicate that temperature is suboptimal for growth. Plants grown at the same temperature had higher leaf starch plus sugar content if they were CO2-enriched than if grown in ambient [CO2], suggesting that an optimal temperature for growth in ambient [CO2] may be suboptimal in elevated [CO2].


2021 ◽  
Vol 53 (1) ◽  
pp. 89-97
Author(s):  
Adalberto Di Benedetto ◽  
Danilo Carnelos ◽  
Jorge Lozano Miglioli ◽  
Pablo Fujinuma ◽  
Ernesto Giardina

Although vegetable nursery growers decide on plug sizes based on the types, production time and schedule of the crops to grow, they usually choose individual small cell sizes because these allow short plant-raising periods and reduced costs. However, larger plugs produce a finished plant after transplant in a shorter period of time than smaller plugs. Nursery growers end the propagation period when roots take up the plug cell and plantlets can be removed from the plug tray without damage. Thus, this study aimed to investigate the effect of three plug-cell sizes and a single BAP application (100 mg L-1) on the shoot and root growth and time to transplant of different lettuce genotypes. Nursery decreased as plug cell volume increased and with the single BAP spray. A novelty result was that the transplant dates were assigned when the marginal root dry weight accumulation decreased, i.e., based on objective rather than on subjective observations. The significant leaf area and dry weight accumulation found could be explained by growth parameters such as the rate of leaf appearance, the relative rate of leaf area expansion, the relative growth rate, the net assimilation rate and the partition coefficient from root: shoot allometries. Highlights Root restriction due to small plugs in transplant trays delay lettuce transplant. Exogenous cytokinin (BAP) overcame root restriction and decreased time to transplant. Time to transplant can be addressed on an objective basis: it were assigned when the marginal root dry weight accumulation decreased.


Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 365-373 ◽  
Author(s):  
David T. Patterson

Texas panicum was grown in controlled-environment chambers in 16 day/night temperature regimes ranging from 19/11 to 34/26 C. After 33 days, maximum plant height, leaf area, and dry weight occurred at 34/26 C. The greatest number of tillers and leaves occurred at 34/16 C. Partitioning of plant biomass into stems increased with increasing night temperature, while partitioning into leaves tended to decrease. Partitioning of biomass into roots decreased with increasing night temperature at day temperatures of 19 or 24 C but not at 34 C. Plant dry matter production (DMP) was highly correlated with both leaf area duration (LAD) and net assimilation rate (NAR) during the first 2 weeks of growth. During the subsequent 3 weeks, DMP was highly correlated with LAD but not with NAR. The low-temperature threshold for growth of Texas panicum was approximately 11 C. Texas panicum attained 25% of its maximum growth at an average daily temperature of 21 C, 50% at 24 C, and 75% at 26 C. Texas panicum is unlikely to become a highly competitive weed outside the southern and southwestern United States.


2016 ◽  
Vol 13 (2) ◽  
pp. 141
Author(s):  
Budhi Priyanto

Sistem fitoremediasi berbasis rumput untuk pengelolaan pencemaran lingkungan di tambang minyak telah diteliti. Lima jenis rumput, yaitu Scirpus grossus, Brachiaria humidicola, Eleusine indica, Paspalum notatum, dan Setaria splendida ditanam pada tanah tercemar minyak lama berkadar 3,1%. Pengaruh cekaman salinitas dievaluasi dengan menambahkan air formasi (850 mg/L TDS) ke dalam tanah. Setelah dua belasminggu, parameter pertumbuhan ditetapkan dan kandungan minyak dalam tanah dianalisis. Hasilnya menunjukkan, bahwa semua jenis rumput dapat tumbuh pada tanah tercemar minyak lama. Di bawah cekaman air formasi, jumlah anakan dan berat kering tunas B. humidicola dan S. splendida jelas tertekan, tetapi panjang akar meningkat. Sebaliknya, berat kering tunas pada S. grossus meningkat di bawah cekaman salinitas. Berat kering akar semua jenis rumput secara nyata berkurang dengan cekaman salinitas. Nisbah berat kering tunas terhadap akar relatif tidak dipengaruhi oleh salinitas. Kegiatan degradasi minyak dipengaruhi oleh cekaman salinitas. Kandungan minyak yang hilang dari tanah berkisar antara 32% hingga 50% pada semua jenis rumput.Kata kunci: pencemaran minyak, fitoremediasi, rumput, air formasi Abstract Experiment to develop a grass based phytoremediation system for environmental management in oil industry has been established in the green house. Five species of grasses, i.e. Scirpus grossus, Brachiaria humidicola, Eleusine indica, Paspalum notatum, dan Setaria splendida, were planted in 6.5 kg oil polluted Semanggi soil (oil content of 3,1%). The effects of salinity were evaluated by adding 800 ml of produced water (850mg/L TDS) to the soil. Growth parameters of the plants and the remaining oil content in the soil were determined in the end of week 12th after planting. The results indicated that all of the grass species are capable of growing well in the polluted soil. However, under the salinity stress, the number of buds on the stolons or rhizomes and the shoot dry weight of B. humidicola and S. splendida are reduced significantly. On the contrary,the root length of the two species is increased; and the shoot dry weight of S. grossus is increased. The root dry weight of all tested species are reduced significantly; however the ratio of shoot dry weight to root dry weight is not influenced by salinity stress. Overall, the oil removal rate from the soil is in the range of 32% to 50%; S. grossus and S. splendida are being the best. The oil degradation activity of the two species is slightly increased under salinity stress condition.Key words: oil polluted soil, phytoremediation, grass, produced water


Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 645-650 ◽  
Author(s):  
D. T. Patterson ◽  
E. P. Flint

Mathematical growth analysis techniques were used to study the effects of simulated field temperatures and chilling events on the growth of the exotic noxious weed itchgrass (Rottboellia exaltataL. f.) and adapted varieties of corn (Zea maysL. ‘DeKalb XL43’ and ‘DeKalb XL395′), and soybean [Glycine max(L.) Merr. ‘Corsoy’, ‘Williams', and ‘Tracy’] in climate-controlled greenhouses and growth chambers. Itchgrass grew vigorously and produced seed in temperature regimes simulating the warmest 4 months of the growing season in the Gulf Coast states (30/25 C, day/night), the central Midwest (27/21 C), and the northern Midwest (23/18 C). At 30/25 C day/night, itchgrass produced 707 g of dry matter and 1907 seed per plant after 119 days. Itchgrass produced 621 g dry matter and 1429 seed at 27/21 C and 499 g dry matter and 1160 seed at 23/18 C. Itchgrass and adapted varieties of corn and/or soybeans were grown in four additional temperature regimes simulating the first 5 weeks of the growing seasons for corn and soybean at Madison, Wisconsin (19/11 C day/night); for soybean at Carbondale, Illinois (24/20 C); for corn at Waycross, Georgia (20/14 C); and for soybean at Baton Rouge, Louisiana (27/23 C). After 24 days of growth, half the plants in each regime were exposed to 3 days of chilling (11/4 C for Madison, 17/10 C for Carbondale, 15/6 C for Waycross, and 24/18 C for Baton Rouge) and returned to the original growth regimes for recovery. The chilling treatments reduced dry matter production, net assimilation rate, and leaf area duration more in itchgrass than in corn or soybean. After recovery, the previously chilled itchgrass plants had greater reductions in height, leaf area, and dry weight, compared to unchilled controls, than did corn or soybean. Weed/crop ratios in height, leaf area, and dry weight for itchgrass/corn were significantly reduced by chilling. In the two cooler regimes, weed/crop ratios in leaf area and dry weight for itchgrass/soybean were significantly reduced by chilling. Because of its sensitivity to cool temperatures, itchgrass, is unlikely to be an important early-season competitor with corn or with soybean outside the South.


1993 ◽  
Vol 23 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Zhang M. Wang ◽  
S. Ellen Macdonald

Morphology and ecophysiology of black spruce (Piceamariana (Mill.) B.S.P.) seedlings grown in a variety of controlled environments were studied in three pairs of adjacent peatland and upland black spruce populations from Alberta. Seedlings were grown in two greenhouse experiments as follows: (i) full factorial combinations of light (100 or 20% of full light in the greenhouse) and moisture (wet, medium, or dry); (ii) full factorial combinations of fertilization (fertilized or unfertilized) and substrate temperature (20 or 8 °C at 5 cm below the surface). In both experiments, morphological (height, top dry weight, root dry weight, total dry weight, and top/root dry weight ratio) and physiological (net assimilation (NA), stomatal and mesophyll conductance to CO2 (gc and gm), and water use efficiency (WUE)) traits were measured. It was found that low light, nutrient stress, and water stress (wet or dry) reduced seedling growth. As moisture decreased or at low light, NA, gc, gm, and WUE decreased. When fertilized, seedlings at low substrate temperature were smaller and had lower NA, gc, and gm than those at high substrate temperature. Results showed no differences in response to the experimental environments between seedlings from peatland versus upland populations. However, upland seedlings were larger than peatland ones, there was greater variation among peatland than among upland populations, and there were site-specific habitat differences. Overall, there was apparently little adaptive ecotypic differentiation in black spruce between the two habitats.


Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum


2018 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Yetti Elidar

Research on the response of roots of palm sugar palm seeds (Arenga pinnata) in nurseries at doses and intervals of Nasa liquid organic fertilizer. Aims to determine the dosage, interval and combination of dosages and fertilization intervals with Nasa liquid organic fertilizer which can provide the best dry weight of the roots in the nursery. The research design used was a Completely Randomized Design (CRD) with 3x3 factorial experiments and each treatment was repeated 8 (eight) times, consisting of: the first factor was the treatment of POC Nasa dose in a concentration of 3 cc POC Nasa per liter of water (D) consists of 3 levels, namely: d1 = 300 ml POC Nasa, d2 = 400 ml POC Nasa, d3 = 500 ml POC Nasa, while the second factor is the treatment of POC Nasa Interval (I) consisting of 3 levels, namely: i1 = 2 once a week, i2 = once every 3 weeks, i3 = once every 4 weeks. The results of the POC Nasa dose study had a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level are: d2 (400 ml of Nasa liquid organic fertilizer), the interval of liquid organic fertilizer Nasa has a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level is: i1 (once every 2 weeks). The treatment combination has no significant effect on all parameters. 


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