Nonlinear Regressions for Analyzing Growth Stage and Quinclorac Interactions

1992 ◽  
Vol 6 (4) ◽  
pp. 898-903 ◽  
Author(s):  
William J. Chism ◽  
Jeffrey B. Birch ◽  
S. Wayne Bingham
Keyword(s):  
Plant Growth ◽  
Nonlinear Regression ◽  
Growth Stage ◽  
Dry Weight ◽  
Weight Basis ◽  
Growth Stages ◽  
Growth Reduction ◽  
True Leaf

Control of southern crabgrass by quinclorac was influenced by plant growth stage. A three-parameter nonlinear regression was used to describe the influence of quinclorac concentration on each growth stage and to compare growth stages. A SAS® program for these comparisons is described. Pseudo R2values for fit were above 0.98 for all tests. Flowering crabgrass plants had the highest GR50value (50% growth reduction on a dry weight basis) whereas preemergence, three- to five-true-leaf, and two- to four-tiller stages were lower.

scholarly journals Growth, Fruit Yield, and Ion Concentration in Tomato Genotypes after Pre- and Post-emergence Salt Treatments

1993 ◽  
Vol 118 (5) ◽  
pp. 655-660 ◽  
Author(s):  
M.C. Bolarín ◽  
F. Pérez-Alfocea ◽  
E.A. Cano ◽  
M.T. Estañ ◽  
M. Caro
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Growth Stage ◽  
Dry Weight ◽  
Fruit Yield ◽  
Ion Concentration ◽  
Growth Stages ◽  
Salt Tolerant ◽  
Shoot Dry Weight ◽  
Advanced Stages

The effects of increasing salinity on dry weight and ion concentration of shoots at various growth stages and on fruit yield in four tomato (Lycopersicon esculentum Mill.) genotypes were assessed. The salt treatments (35, 70, and 140 mm NaCl) were applied pre-emergence (seed sowing) (pre-E) and post-emergence (four-leaf stage) (post-E) and maintained during plant growth. Genotype salt tolerance, measured as shoot dry weight in response to increases in salt concentration, varied depending on plant growth stage and salt application time. When salt was applied pre-E, salt tolerance increased with plant age, whereas when applied post-E, 45-day-old plants were the most salt tolerant. Mature plants were similarly salt tolerant independent of the growth stage at which the salt treatments began. However, fruit yield of all genotypes was higher when salt was applied pre-E than post-E. Shoot dry weight decreased as shoot Cl and Na ion concentrations increased. During early growth stages, pre-E salt-treated plants had the highest Cl-and Na+ concentrations and the lowest shoot dry weights. However, at the advanced stages, shoot Cl- and Na Concentrations were equal for both salt application times. These results show that the plants must adapt to salinity during a period that allows them to develop a mechanism to regulate internal Cl- and Na+ concentrations and, thus, grow under high salinity.

scholarly journals Hormesis with glyphosate depends on coffee growth stage

2013 ◽  
Vol 85 (2) ◽  
pp. 813-822 ◽  
Author(s):  
LEONARDO B. DE CARVALHO ◽  
PEDRO L.C.A. ALVES ◽  
STEPHEN O. DUKE
Keyword(s):  
Plant Growth ◽  
Weed Management ◽  
Growth Stage ◽  
Growth Stages ◽  
Coffee Plant ◽  
Herbicide Application ◽  
Coffee Plantations ◽  
Plant Growth Stages ◽  
Coffee Plants ◽  
Almost All

Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on coffee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.

scholarly journals Scale-Dependent Effects of Growth Stage and Elevational Gradient on Rice Phyllosphere Bacterial and Fungal Microbial Patterns in the Terrace Field

2022 ◽  
Vol 12 ◽  
Author(s):  
Pei Wang ◽  
Jianping Dai ◽  
Luyun Luo ◽  
Yong Liu ◽  
Decai Jin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Stage ◽  
Elevational Gradient ◽  
Fungal Communities ◽  
Growth Stages ◽  
Strong Positive Correlation ◽  
Elevation Gradients ◽  
Positive Correlation ◽  
Α Diversity ◽  
Phyllosphere Bacteria

The variation of phyllosphere bacterial and fungal communities along elevation gradients may provide a potential link with temperature, which corresponds to an elevation over short geographic distances. At the same time, the plant growth stage is also an important factor affecting phyllosphere microorganisms. Understanding microbiological diversity over changes in elevation and among plant growth stages is important for developing crop growth ecological theories. Thus, we investigated variations in the composition of the rice phyllosphere bacterial and fungal communities at five sites along an elevation gradient from 580 to 980 m above sea level (asl) in the Ziquejie Mountain at the seedling, heading, and mature stages, using high-throughput Illumina sequencing methods. The results revealed that the dominant bacterial phyla were Proteobacteria, Actinobacteria, and Bacteroidetes, and the dominant fungal phyla were Ascomycota and Basidiomycota, which varied significantly at different elevation sites and growth stages. Elevation had a greater effect on the α diversity of phyllosphere bacteria than on that phyllosphere fungi. Meanwhile, the growth stage had a great effect on the α diversity of both phyllosphere bacteria and fungi. Our results also showed that the composition of bacterial and fungal communities varied significantly along elevation within the different growth stages, in terms of both changes in the relative abundance of species, and that the variations in bacterial and fungal composition were well correlated with variations in the average elevation. A total of 18 bacterial and 24 fungal genera were significantly correlated with elevational gradient, displaying large differences at the various growth stages. Soluble protein (SP) shared a strong positive correlation with bacterial and fungal communities (p < 0.05) and had a strong significant negative correlation with Serratia, Passalora, unclassified_Trichosphaeriales, and antioxidant enzymes (R > 0.5, p < 0.05), and significant positive correlation with the fungal genera Xylaria, Gibberella, and Penicillium (R > 0.5, p < 0.05). Therefore, it suggests that elevation and growth stage might alter both the diversity and abundance of phyllosphere bacterial and fungal populations.

scholarly journals Biological Control of the Weedy Plant (Rumex crispus) at the Seedling Growth Stage by the Green Dock Beetle (Gastrophysa viridula)

2019 ◽  
Vol 28 (1) ◽  
pp. 21-31
Author(s):  
Khalid S. Alshallash Khalid S. Alshallash
Keyword(s):  
Biological Control ◽  
Seedling Growth ◽  
Growth Stage ◽  
Biological Control Agent ◽  
Dry Weight ◽  
Control Agent ◽  
Growth Stages ◽  
Rumex Crispus ◽  
Shoot Number ◽  
The Impact

In four glasshouse experiments, the effectiveness of the adult green dock beetle Gastrophysa viridula (Coleoptera: Chrysomelidae), at the effective number of applied individuals, for use as a biological control agent of curled dock, Rumex crispus (Polygonaceae) were studied. The feeding of the beetle was investigated at four different numbers of beetle (0, 1, 2, 3) and at four seedling growth stages of the plant, defined by the average of leaf area per plant (1-1.22 , 2-4.45, 3-11.56, and 4-71.52 cm2/plant). Grazing by one, two or three dock beetles did not result in a significant reduction in dock dry weight or shoot numbers at the youngest growth stage. However, both at later seedling growth stages were significantly affected (P ? 0.0001), at any beetles number. The increase of beetle numbers caused nonsignificant increased effect, in some trials, confirming the impact of a single beetle. Three months after beetle grazing, dock seedlings of first, second and third growth stages were not able to regrow, however, some plants at the 4th growth stage, re-emerged. This suggested that the highest effect of beetle's feeding occurs on the early seedling stages. Statistical analysis showed a positive correlation (0.77) between dry weight and shoot number at all the four seedling growth stages, thus confirming the impact of the beetle on both the dry weight and shoot numbers. Combining beetle grazing with other control methods at older dock seedling stages could, therefore, provide better suppression

Response of nonglyphosate-resistant cotton to reduced rates of glyphosate

Weed Science ◽  
2004 ◽  
Vol 52 (1) ◽  
pp. 178-182 ◽  
Author(s):  
Donnie K. Miller ◽  
Robert G. Downer ◽  
B. Roger Leonard ◽  
E. Merritt Holman ◽  
Steve T. Kelly
Keyword(s):  
Data Analysis ◽  
Plant Height ◽  
Growth Stage ◽  
Field Research ◽  
Dry Weight ◽  
White Flower ◽  
Growth And Yield ◽  
Growth Stages ◽  
Flower Number ◽  
Height Reduction

Field research was conducted in 1999 and 2000 to determine the effect of reduced glyphosate rates on growth and yield of nonglyphosate-resistant cotton. Rates of 9, 18, 35, 70, 140, and 280 g ha−1, representing 0.008, 0.016, 0.031 0.063, 0.125, and 0.25, respectively, of the maximum use rate per application (1,120 g ha−1), were applied to cotton at the two-, five-, or nine-node growth stage. On the basis of visual injury estimates, cotton was more tolerant to glyphosate at the nine-node than at earlier growth stages. Plant dry weight was reduced with 70 g ha−1of glyphosate or higher, when applied at the two- and five-node growth stages in two of three experiments. Dry weight was not affected by glyphosate at the nine-node stage. Plant height also was unaffected by glyphosate rates below 70 g ha−1, but height reduction was noted for all growth stages by experiment combinations, with the exception of the nine-node application for both experiments in 2000, with herbicide rates of 70 g ha−1or higher. Cotton maturity delay, as noted by an increase in node above white flower number, was observed only at the highest glyphosate rate applied to two- and five-node cotton in one of three experiments. Percent open boll data analysis indicated a decreased opportunity of observing an open boll with increasing glyphosate rate, and this effect was greater at the five-node compared with the two- and nine-node stages in two of three experiments. Seedcotton yield after all glyphosate applications was equivalent to that for the nontreated control.

scholarly journals Pepper Transplants Are Excessively Damaged by Brushing

HortScience ◽  
1994 ◽  
Vol 29 (9) ◽  
pp. 1002-1003 ◽  
Author(s):  
Joyce G. Latimer
Keyword(s):  
Plant Growth ◽  
Capsicum Annuum ◽  
Growth Regulation ◽  
Mechanical Damage ◽  
Stem Length ◽  
Pepper Plant ◽  
Growth Reduction ◽  
Higher Plant ◽  
True Leaf ◽  
Quality Ratings

`Jupiter' or `Marengo' pepper (Capsicum annuum L.) seedlings maintained under 0%, 30%, 50%, or 80% shade in a greenhouse were brushed 80 strokes twice daily beginning at the cotyledonary, first true leaf, or second true leaf stage. Averaged across shade environments, brushing reduced `Jupiter' and `Marengo' stem length 25% to 36% and 6% to 28%, respectively. However, the percentage of plants exhibiting mechanical damage by brushing ranged from 86% to 93% and 48% to 90% for `Jupiter' and `Marengo', respectively. Transplant quality tended to decrease as brushing was delayed. When brushing of `Marengo' was reduced to 40 strokes twice daily in 1992, plant growth reduction decreased, but the percent damage was about the same. The damage severity, however, was reduced as indicated by higher plant-quality ratings. Pepper plant damage was excessive for the small amount of growth regulation provided by brushing.

scholarly journals Toxic affects of chromium on some quality parameters of Sorghum bicolor (L.)

2018 ◽  
Vol 10 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Sweety Sihag ◽  
U. N. Joshi
Keyword(s):  
Sorghum Bicolor ◽  
Protein Content ◽  
Chlorophyll Content ◽  
Potassium Dichromate ◽  
Dry Weight ◽  
Quality Parameters ◽  
Weight Basis ◽  
Growth Stages ◽  
Fresh Weight ◽  
Sorghum Bicolor L

A pot experiment was conducted to determine the effects of varying Cr (VI) levels [0.0–4.0 mg Cr (VI) kg-1 soil in the form of potassium dichromate] on the some quality parameters of sorghum Sorghum bicolor (L.). Quality parameters was measured in terms of protein content, chlorophyll content, and IVDMD ( In vitro dry matter digestibility) content at different growth stages, i.e. 35 DAS, 70 DAS and 90 DAS (Days after sowing) that were adversely affected with an increase in Cr (VI) levels from 0.0 to 4.0 mg Cr (VI) kg-1 soil. The decline in protein content 4.67 g/ kg dry weight at T4 was observed as compared to control (T1) ( 8.96 g/kg dry weight basis) at 35 DAS in leaves , Total chlorophyll content declined from 3.25 mg g-1 fresh weight (T1) to 2.40 mg g-1 fresh weight (T4) at 35 DAS and IVDMD content declined from 43.60 to 33.60 per cent dry weight basis with increment in chromium concentration. It is concluded that Cr (VI) at higher doses (4.0 mg Cr (VI) kg-1 soil) adversly affects the quality parameters of Forage sorghum Sorghum bicolor (L.) however, quality parameters are responsible for nutritive value of sorghum Sorghum bicolor (L.).

Reduction by GA3 of Nacl-Induced Inhibition of Growth and Development in Suaeda ussuriensis

1986 ◽  
Vol 13 (4) ◽  
pp. 547 ◽  
Author(s):  
KF Zhao ◽  
ML Li ◽  
JY Liu
Keyword(s):  
Plant Growth ◽  
Growth Inhibition ◽  
Salt Concentration ◽  
Growth And Development ◽  
Dry Weight ◽  
Weight Basis ◽  
Inhibition Of Growth ◽  
Optimum Salt Concentration

Seedlings of Suaeda ussuriensis were grown in soil with NaCl concentrations of 0.5, 1.0, 2.0 and 3.0% on a dry weight basis. The optimum salt concentration for growth and development was 1.0%. At 3.0% all seedlings died. Treatment with 10*5 �g/litre GA3 counteracted partly the growth inhibition, and the dry weight of plants increased 21.6, 2.2 and 19.4%, respectively, for soils with salt concentrations of 0.5, 1.0 and 2.0%. GA*3 increased the numbers of plants coming to flower in soil of salt concentration of 0.5 and 2.0%, by 40 and 20%, respectively, but had no effect on plant growth in a salt concentration of 1.0%.

Efficacy ofColletotrichum coccodesand Thidiazuron for Velvetleaf (Abutilon theophrasti) Control in Soybean (Glycine max)

1988 ◽  
Vol 2 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Richard H. Hodgson ◽  
Lee A. Wymore ◽  
Alan K. Watson ◽  
Robert H. Snyder ◽  
Anne Collette
Keyword(s):  
Glycine Max ◽  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Growth Stage ◽  
Pathogenic Fungus ◽  
Abutilon Theophrasti ◽  
Colletotrichum Coccodes ◽  
Growth Stages ◽  
Wet Weather

The plant pathogenic fungusColletotrichum coccodes(Cc) and the plant growth regulator thidiazuron (TDZ) were evaluated in Maryland and Quebec for velvetleaf control in ‘Williams' and ‘Maple Arrow’ soybean. TDZ was applied at 0, 0.1, 0.2, 0.3, and 0.4 kg ai/ha alone or was combined with Cc at 109spores/m2when velvetleaf was at the 1- to 2-leaf (Trial 1) or 4- to 6-leaf (Trial 2) growth stages. Velvetleaf control increased with TDZ rate, and TDZ combined with Cc further increased control. TDZ reduced velvetleaf biomass and height, and Cc increased velvetleaf mortality. In Quebec, Cc also reduced the biomass of velvetleaf treated in Trial 1 and interacted positively with TDZ at this growth stage. Cc nearly halved the rates of TDZ required for 90 and 75% mortality of velvetleaf treated at the 1- to 2-leaf and 4- to 6-leaf stages to 0.09 and 0.12 kg/ha, respectively, in Quebec. Cc similarly lowered the rate of TDZ required for 75% stand reduction of velvetleaf in Trial 1 to 0.17 kg/ha in Maryland. Cool wet weather in Quebec contrasted with warm, dry weather in Maryland. Soybean biomass and yield were increased significantly by treatment with TDZ plus Cc in Trial 1 at both locations.

scholarly journals Dosage of 2,6-Bis (1.1-Dimethylethyl)-4-Methylphenol (BHT) in the Plant ExtractMesembryanthemum crystallinum

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Bouftira Ibtissem ◽  
Mgaidi Imen ◽  
Sfar Souad
Keyword(s):  
Antioxidant Activity ◽  
Plant Growth ◽  
Plant Extract ◽  
Growth Stage ◽  
Mesembryanthemum Crystallinum ◽  
Growth Stages ◽  
Naturally Occurring ◽  
Plant Growth Stages

A naturally occurring BHT was identified in the leaves of the halophyte plantMesembryanthemum crystallinum. This phenol was extracted in this study by two methods at the different plant growth stages. One of the methods was better for BHT extraction; the concentration of this phenol is plant growth stage dependent. In this study, the floraison stage has the highest BHT concentration. The antioxidant activity of the plant extract was not related to BHT concentration. The higher antioxidant activity is obtained at seedlings stage.

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