scholarly journals Phytoextraction of lead by Helianthus annuus: effect of mobilising agent application time

2008 ◽  
Vol 54 (No. 10) ◽  
pp. 434-440 ◽  
Author(s):  
A.A. Safari Sinegani ◽  
F. Khalilikhah
Keyword(s):  
Helianthus Annuus ◽  
Ethylenediaminetetraacetic Acid ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Application Time ◽  
Growth Depression ◽  
Sheep Manure ◽  
Edta Concentration ◽  
Sunflower Seedling ◽  
Severe Growth

Pot experiments were conducted to determine the best time for application of (ethylenediaminetetraacetic acid) EDTA and sheep manure extract (SME) in phytoremediation of a contaminated soil by <I>Helianthus annuus</I>. The plant was grown in a mine calcareous soil treated with increasing concentrations of EDTA or SME in 30 and 10 days before sowing (T1 and T2) and 10 and 30 days after sowing (T3 and T4). The best time for EDTA application was T4. The EDTA application before seed germination significantly reduced sunflower seedling emergence and dry weight. Soil available Pb and lead concentrations in plant organs increased with EDTA concentration but the actual amount of phytoextracted Pb decreased at high EDTA concentrations significantly, due to severe growth depression. SME application after sowing can increase plant dry weight and Pb concentration in the soil solution, enhancing the accumulated metal concentrations in shoots and roots. However the results showed that the most efficient treatments for Pb phytoextraction by sunflower are applications of 0.5 and 2 g EDTA/kg soil at T3 and T4, respectively.

WILD MUSTARD CONTROL IN SUNFLOWER WITH FLURTAMONE

1990 ◽  
Vol 70 (4) ◽  
pp. 1195-1197 ◽  
Author(s):  
G. H. FRIESEN ◽  
D. A. WALL
Keyword(s):  
Helianthus Annuus ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Sinapis Arvensis ◽  
Helianthus Annuus L ◽  
Wild Mustard ◽  
Annual Weeds ◽  
Sunflower Seedling ◽  
Brassica Kaber

Flurtamone applied preplant soil incorporated at 0.6 and 0.8 kg a.i. ha−1 selectively controlled wild mustard, Brassica kaber (DC) Wheeler var. pinnatifida (Stokes) Wheeler, in sunflower (Helianthus annuus L. ’Hybrid Sun M20’) in field experiments at Morden, Manitoba from 1987 to 1989. Mixtures of flurtamone and trifluralin or ethalfluralin did not reduce the efficacy of flurtamone and controlled a broad range of annual weeds. Flurtamone had no significant effect on sunflower seedling emergence, achene yields, achene weight, achene density, or oil content.Key words: Wild mustard, Sinapis arvensis, Brassica kaber, sunflower, Helianthus annuus, flurtamone, RE-40885

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

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

EMERGENCE AND SEEDLING GROWTH OF INBRED LINES OF CORN AT SUBOPTIMAL ROOT-ZONE TEMPERATURES

1987 ◽  
Vol 67 (2) ◽  
pp. 409-415 ◽  
Author(s):  
A. MENKIR ◽  
E. N. LARTER
Keyword(s):  
Zea Mays ◽  
Seedling Growth ◽  
Root Zone ◽  
Seedling Emergence ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Inbred Lines ◽  
Root Zone Temperature ◽  
Emergence Percentage ◽  
Zone Temperature

Based on the results of an earlier paper, 12 inbred lines of corn (Zea mays L.) were evaluated for emergence and seedling growth at three controlled root-zone temperatures (10, 14, and 18 °C). Low root-zone temperatures, 10 and 14 °C, were detrimental to emergence, seedling growth, and root growth of all inbred lines. Differential responses of inbred lines were observed within each temperature regime. The differences in seedling emergence among lines became smaller with increasing root-zone temperature, while the reverse was true for seedling dry weight. Simple correlation coefficients showed a significantly (P = 0.05) negative association between emergence percentage and emergence index (rate). Neither of these two emergence traits was significantly correlated with seedling dry weights. Seedling dry weights were significantly (P = 0.01) and positively associated with root dry weights. Two inbred lines exhibited good tolerance to low root-zone temperatures, viz. CO255 and RB214. A significant and positive correlation existed between emergence percentage at a root-zone temperature of 10 °C and field emergence in test with the same genotypes reported earlier. Selection at a root-zone temperature of 10 °C for a high percentage of seedling emergence, therefore, could be effective in identifying genotypes capable of germinating in cool soils. Furthermore, the significantly (P = 0.01) positive relationship between seedling dry weights at all root-zone temperatures and those from the field test suggest that strains with vigorous seedling growth in the field could be identified using low root-zone temperature regimes.Key words: Zea mays, root-zone temperature, cold tolerance

scholarly journals Effect of different levels of humic acids on the nutrient content, plant growth, and soil properties under conditions of salinity

2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy
Keyword(s):  
Plant Growth ◽  
Humic Substances ◽  
Humic Acids ◽  
Foliar Application ◽  
N Uptake ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Nutrient Elements ◽  
A Minor

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.

scholarly journals Exogenous Antioxidants Enhance Seedling Growth and Yield of Artificially Aged Cabbage and Lettuce Seeds

Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 274
Author(s):  
Ademola Adetunji ◽  
Sershen ◽  
Boby Varghese ◽  
Norman Pammenter
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Growth And Yield ◽  
Seed Vigour ◽  
Beneficial Effects ◽  
Shoot Dry Weight ◽  
Antioxidant Defence System ◽  
Aged Seeds

Aged seeds exhibit compromised vigour in terms of germination, seedling emergence and growth, but this can to some extent be alleviated by invigoration treatments before sowing. This study aimed to investigate ageing rates and patterns in cabbage (Brassica oleraceae) and lettuce (Lactuca sativa) seeds and whether the beneficial effects of invigorating aged seeds with exogenous antioxidants translate to enhanced seedling performance. Seeds were artificially aged to 25% viability before soaking in 0.4 mM glycerol, 0.6 mM GSH and 0.2 mM trolox for cabbage, and 0.6 mM glycerol, GSH and trolox for lettuce; deionised water served as a control. After 14 days of sowing, seedling emergence percentage, mean emergence time, mean daily emergence, and time taken to 25% emergence were computed. Seedling vigour index, root and shoot dry weight, root:shoot ratio, leaf area, leaf area ratio, and leaf chlorophyll content were assessed 6 weeks after sowing. Furthermore, the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), and chlorophyll fluorescence were measured 6 weeks after sowing. Notably, ageing resulted in the loss of seed vigour and viability at higher rates in lettuce than cabbage. Seed pretreatment with glycerol promoted seedling growth in both species and shoot dry weight in lettuce, while glycerol and GSH enhanced Pn, Gs and E in lettuce. Trolox also enhanced Pn and E in lettuce. The beneficial effects of the antioxidant treatments are thought to be associated with the protection of photosystems from oxidative stress and/or stimulation of enzymes involved in photosynthesis, possibly through an enhanced antioxidant defence system during the early development stages when seedlings are particularly vulnerable to stress.

Dicamba, Chlorsulfuron, and Clopyralid as Sprayer Contaminants on Sunflower (Helianthus annuus), Mustard (Brassica juncea), and Lentil (Lens culinaris), Respectively

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 616-621 ◽  
Author(s):  
Douglas A. Derksen
Keyword(s):  
Helianthus Annuus ◽  
Lens Culinaris ◽  
Field Experiments ◽  
Yield Loss ◽  
Dry Weight ◽  
Yield Losses ◽  
Crop Tolerance ◽  
Crop Injury ◽  
Untreated Check ◽  
Grass Weed

Simulated sprayer tank residues of the broadleaf weed herbicides dicamba, chlorsulfuron, and clopyralid applied alone and with the grass weed herbicides sethoxydim and diclofop on sunflower, tame mustard, and lentil, respectively, caused visible crop injury and reduced dry weight and yield. Dry weight production in the greenhouse and crop tolerance ratings in the field indicated that the grass weed herbicides enhanced crop injury from dicamba, chlorsulfuron, and clopyralid. Yield reductions in field experiments were also greater when dicamba and clopyralid were mixed with grass weed herbicides and applied on sunflower and lentil, respectively. This did not occur with chlorsulfuron applied to mustard. When mixed with simulated broadleaf weed herbicide residues, diclofop enhanced dry weight reductions and crop injury and reduced yield to a greater extent than sethoxydim. Crop tolerance ratings differentiated treatments and rates but were not a good estimate of the extent of yield loss. When broadleaf weed herbicides were applied at rates simulating sprayer tank residues alone or combined with grass weed herbicides, yield losses ranged up to 40% in sunflower, 70% in mustard, and 95% in lentil, compared to the untreated check.

scholarly journals Evaluation of Chickpea (Cicer arietinum L.) Genotypes for Quality Seedlings

1970 ◽  
Vol 8 (2) ◽  
pp. 108-116
Author(s):  
Shahrina Akhtar ◽  
Jalal Uddin Ahmed ◽  
Abdul Hamid ◽  
Md Rafiqul Islam
Keyword(s):  
Biomass Production ◽  
Plant Biomass ◽  
Function Analysis ◽  
Dominant Role ◽  
Seedling Emergence ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Total Biomass ◽  
Maximum Variance ◽  
Total Dry Weight

A study was conducted to evaluate 100 chickpea genotypes to explore their genetic diversity in respect of emergence and growth attributes. A high genotypic variation was observed in the characters studied. The highest positive correlation corresponded to the root mass and total plant biomass of the seedlings. Seedling biomass production was highly subjective to seedling vigor. Using discriminant function analysis, the first two functions contributed 46.2 and 39.0%, and altogether 85.2% of the variability among the genotypes. Function 1 was positively related to dry weight of root and total plants. The character with the greatest weight on function 2 was seedling emergence rate. The total dry weight of seedlings played the most dominant role in explaining the maximum variance in the genotypes. The genotypes were grouped into six clusters. Each cluster had specific seedling characteristics and the clusters 5 and 6 were closely related and clearly separated from clusters 1 and 4 for their higher amount of root and total biomass production, and vigorous seedlings, where as, the genotypes in cluster 2 and 3 were intermediate. The genotypes in cluster 5 followed by cluster 6 appeared to be important resources for selecting and developing chickpea variety. Keywords: Chickpea; genotypes; seedling; quality DOI: 10.3329/agric.v8i2.7584 The Agriculturists 8(2): 108-116 (2010)

Kochia (Kochia scoparia) Interference in Sunflower (Helianthus annuus)

1990 ◽  
Vol 4 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Beverly R. Durgan ◽  
Alan G. Dexter ◽  
Stephen D. Miller
Keyword(s):  
Helianthus Annuus ◽  
Plant Height ◽  
Oil Content ◽  
Field Experiments ◽  
Yield Loss ◽  
Dry Weight ◽  
Kochia Scoparia

Field experiments were conducted in 1983 and 1984 at two locations to determine the influence of various densities and durations of kochia interference in sunflower. Sunflower achene yield and dry weight were reduced by all densities of kochia, averaged over locations and years. Season-long competition by kochia densities of 0.3, 1, 3, and 6 plants/m of row decreased sunflower achene yield 7, 10, 20, and 27%, respectively. Sunflower achene yield and sunflower dry weight decreased as weeks of kochia competition increased. Only 2 weeks of kochia competition after sunflower emergence decreased sunflower achene yield 6%. Sunflower achene yield loss increased as the duration of kochia competition increased. Sunflower 200 achene weight, oil content, and plant height were not influenced by various densities or durations of kochia competition.

scholarly journals Cambios histomorfométricos en dentina al utilizar biomodificadores radiculares. Revisión sistemática / Histomorphometric Changes in Root Dentine after using Biomodifiers. A Systematic Review

2017 ◽  
Vol 36 (76) ◽  
Author(s):  
Paola Inés Tous Yemail ◽  
Sandra Yasnini García Ferrer ◽  
Eduardo Covo Morales ◽  
Luis Carlos Fang Mercado
Keyword(s):  
Systematic Review ◽  
Citric Acid ◽  
Ethylenediaminetetraacetic Acid ◽  
Scientific Evidence ◽  
Smear Layer ◽  
Application Time ◽  
Root Canal Preparation ◽  
Dentin Surface ◽  
Revisión Sistemática ◽  
Standard Difference

<p><strong>ABSTRACT. </strong><strong><em>Background</em></strong>: The success of endodontic therapy depends on an optimal biomechanical preparation, which includes removal of smear layer formed during root canal preparation. Smear layer adheres to the dentin surface and occludes the tubules, preventing the adhesion of the sealant material. It must be removed through irrigants that cause changes on the dentinal surface. Ethylenediaminetetraacetic acid (EDTA), citric acid, and tetracycline have been used as irrigants. <strong><em>Purpose</em></strong>: To identify changes in dentine after applying EDTA, citric acid, and tetracycline as irrigants, as described in available literature. <strong><em>Methods</em></strong>: In this systematic review, histomorphometric changes in dentin surface observed after using root biomodifiers, regarding application time and concentration of solution. The sample consisted of 20 articles selected from a population of 889 articles found and published between 2009 and 2016. The overall measure of results was the standard difference of dentinal demineralization depth, obtained for each solution. <strong><em>Results</em></strong>: According to the literature, the depth of demineralization is directly proportional to exposition time and concentration after application of the irrigant. Regarding other variables, such as pH, evidence was limited to draw conclusions. Thus, it is suggested there is not enough scientific evidence to support this type of study. <strong><em>Conclusions</em>:</strong> Dentinal changes that occur after using root biomodifiers depend on the length of the application time and its concentration.</p>

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