scholarly journals Modelling the structural response of cotton plants to mepiquat chloride and population density

2014 ◽  
Vol 114 (4) ◽  
pp. 877-887 ◽  
Author(s):  
Shenghao Gu ◽  
Jochem B. Evers ◽  
Lizhen Zhang ◽  
Lili Mao ◽  
Siping Zhang ◽  
...  
Keyword(s):  
Population Density ◽  
Structural Response ◽  
Mepiquat Chloride ◽  
Cotton Plants

scholarly journals Changes in the Activities of Protective Enzymes Induced by Mepiquat Chloride (DPC) in Cotton to Defend Against Aphids

2021 ◽  
Author(s):  
Quancheng Zhang ◽  
Xiaoxia Deng ◽  
Jungang Wang
Keyword(s):  
Population Density ◽  
Soluble Protein ◽  
Defense Mechanism ◽  
Specific Activity ◽  
Induced Defense ◽  
Insect Population ◽  
Detoxification Enzymes ◽  
Sod Activity ◽  
Mepiquat Chloride ◽  
Protective Enzymes

Abstract Background: Mepiquat chloride (DPC) enhances the resistance of cotton plants, and it is widely used as a growth regulator. DPC can stimulate photosynthesis, stabilize the structure of cotton leaves, and affect population reproduction and energy substances in cotton aphids, but interactions between DPC and cotton aphids remain unclear. In this study, we analyzed the physiological responses of cotton to DPC, and the toxicity of DPC toward cotton aphids, before and after feeding, to explore the DPC-induced defense mechanism against cotton aphids.Results: Measurements of protective enzyme activity in cotton showed that the soluble protein contents, peroxidase (POD) activity, and catalase (CAT) activity in cotton treated with different concentrations of DPC were higher than in the control. Superoxide dismutase (SOD) activity was higher than that of controls when the concentration of DPC was <0.1 g/L. Under aphid stress, POD activity of cotton treated with a low insect population density was significantly lower than that of controls, but the reverse was true for cotton treated with a high insect population density, and SOD activity was positively correlated with population density. The activities of detoxification enzymes in field and laboratory experiments showed that DPC promoted the specific activity of glutathione S-transferase (GST) in cotton aphids, while the specific activities of carboxylesterase and acetylcholinesterase were decreased.Conclusions: DPC enhanced the resistance of cotton by increasing the activity of protective enzymes. It also had a toxic effect on cotton aphids by increasing GST activity (the main DPC target) and lowering carboxylesterase and acetylcholinesterase activities. DPC increased the soluble protein content and SOD activity in cotton under aphid stress, and thereby enhanced tolerance to cotton aphids.

scholarly journals Rainfall intensity and Mepiquat Chloride persistence in cotton

2007 ◽  
Vol 64 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Fábio Suano de Souza ◽  
Ciro Antonio Rosolem
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Dry Matter ◽  
Rainfall Intensity ◽  
Mepiquat Chloride ◽  
Reproductive Structures ◽  
Cotton Plants ◽  
Dry Matter Weight

In some regions where cotton is grown in Brazil rainfall amounts to about 2,000 mm per year, which imposes a great risk for Mepiquat Chloride (MP) to be washed from cotton leaves before being absorbed. The objective of this research was to evaluate the MC persistence when applied on cotton plants submitted to different rain intensities after spraying. The treatments were three MC rates: 0, 15.0 and 30.0 g a.i. ha-1 and four simulated rainfalls, applied 90 minutes after MC spraying: 5, 10, 20 and 40 mm, plus a treatment without rain. Cotton plants of the cv. Delta Opal were grown in 12 L pots filled with an Haplortox. The experimental design was consisted of complete randomized blocks, in a factorial scheme, with four replicates. The evaluated parameters were: plant height, number of reproductive branches, dry matter weight, reproductive structures, retention and leaf area. The higher the rainfall the lower the effectiveness of the plant growth regulator in controlling plant height. A simulated rainfall as low as 5 mm occurring 90 minutes after MC application was enough to wash some of the plant growth regulator from cotton leaves.

Carbon and Water Economies of Well‐Watered and Water‐Deficient Cotton Plants Treated with Mepiquat Chloride

Crop Science ◽  
1992 ◽  
Vol 32 (1) ◽  
pp. 175-180 ◽  
Author(s):  
C. J. Fernández ◽  
J. T. Cothren ◽  
K. J. McInnes
Keyword(s):  
Mepiquat Chloride ◽  
Cotton Plants

scholarly journals Effect of population densities of Pratylenchus brachyurus on the growth of cotton plants

2001 ◽  
Vol 26 (2) ◽  
pp. 192-196 ◽  
Author(s):  
MÁRIO M. INOMOTO ◽  
ALEXANDRE M. C. GOULART ◽  
ANDRESSA C. Z. MACHADO ◽  
AILTON R. MONTEIRO
Keyword(s):  
Population Density ◽  
Gossypium Hirsutum ◽  
Plant Height ◽  
Root Weight ◽  
Population Densities ◽  
Greenhouse Experiments ◽  
Cotton Plants ◽  
Pratylenchus Brachyurus ◽  
Fresh Root

The effect of different population densities of Pratylenchus brachyurus on the growth of cotton (Gossypium hirsutum) plants was studied in three greenhouse experiments, using cultivars IAC 20 and IAC 22. Both cultivars proved to be good hosts to the nematode, which however did not affect plant height and affected only slightly fresh root weight and dry top weight of both cultivars, even at the highest population density (over 9,000 nematodes/plant).

scholarly journals Anatomic Characterization and Photosynthetic Rate in Cotton Genotypes due the Mepiquat Chloride

2017 ◽  
Vol 9 (12) ◽  
pp. 122
Author(s):  
Amanda Pereira Paixão ◽  
Aline Redondo Martins ◽  
Simone Silva Hiraki ◽  
Liliane Santos de Camargos ◽  
Luis Henrique Marani Daruichi Machado ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Growth Regulator ◽  
Photosynthetic Apparatus ◽  
Field Conditions ◽  
Total Thickness ◽  
Mepiquat Chloride ◽  
Genetic Characteristics ◽  
Cotton Plants ◽  
Cotton Genotypes

The FMT 701 and Fibermax 966 genotypes of the herbaceous cotton plants showed distinct morphophysiological characteristics due to their unique genetics. Henceforth, they are likely to have differences both in the foliar anatomic characters and in the photosynthetic apparatus due to the application of the mepiquat chloride (MC) growth regulator. The goal of the present work was to assess two genotypes of cotton plants with unique genetic characteristics through the application of increasing doses of MC by means of anatomic analyses of the foliar limb. The experiment was led in field conditions in the region of Cerrado, and experimental delineation employed was the randomized blocks, in a 5 × 2 factorial scheme totaling 10 treatments, with 4 repetitions making up a total of 40 parcels. MC was applied through foliar route, parceled in three applications performed 50, 60 and 70 days after the emergence, and such treatments consisted of the application of fours doses of MC (500; 1,000; 1,500; 2,500 mL ha-1) and a witness. The results obtained from the FMT 701 and Fibermax 966 genotypes suggest that MC exerted distinct influence upon the thicknesses of the adaxial and abaxial epidermises, palisade and lacuna parenchyma and the total thickness of both the internervural region and the region next to the central nervure. The number of adaxial stomata was reduced due to the doses of MC, exerting influence upon the photosynthetic rate in both genotypes.

Modification of yield components and stem length in spring barley by the application of growth retardants prior to main shoot stem elongation

1986 ◽  
Vol 107 (2) ◽  
pp. 367-375 ◽  
Author(s):  
S. R. Waddington ◽  
Phyllis Cartwright
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Yield Components ◽  
Stem Elongation ◽  
Spring Barley ◽  
Plant Population ◽  
Stem Length ◽  
Growth Retardants ◽  
Main Shoot ◽  
Mepiquat Chloride

SummaryThe ability of mepiquat chloride and chlormequat growth retardants to modify grain yield components and stem length in two contrasting spring barley cultivars was evaluated in 2 years of small scale field experiments in central southern England. Interactions with plant population density and sowing date were studied.The mid-tall cv. Koru was more responsive than the shorter high tillering ‘erectoides’ cv. Goldmarker. Early treatments of mepiquat chloride (applied before the start of main shoot stem elongation) on Koru raised grain yield/plant in both years. Early treatments with chlormequat and later applications (during main shoot stem elongation) of either retardant were largely ineffective. Yield increases were achieved by raising the number of spikes/plant along with the number of grains/spike and the above-ground biomass in certain later-formed, lower ranking shoots.A medium plant population density (250 plants/m2) allowed the best response to early treatment with mepiquat chloride, as did a normally-timed sowing in contrast to a late one. Retardant-induced improvements in yield components in Koru were positively correlated with plant height, the result of over-compensation in the length of upper internodes.It appears that effective treatments reduced the dominance of the main shoot during tillering, allowing greater initiation and survival of florets (grain sites) in smaller shoots.

scholarly journals Growth regulator losses from cotton plants due to rainfall

2010 ◽  
Vol 67 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Rodrigo Arroyo Garcia ◽  
Mariana Zampar Toledo ◽  
Ciro Antonio Rosolem
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Growth Regulators ◽  
Dry Matter ◽  
Seedling Emergence ◽  
Gossypium Hirsutum L ◽  
Chlormequat Chloride ◽  
Mepiquat Chloride ◽  
Cotton Plants ◽  
Product Loss

Plant growth regulators (PGRs) applied to cotton plants (Gossypium hirsutum L.) can be washed off by rainfall. It is expected that the closer the rainfall to spraying time, the higher the product loss and the higher the amount of product to be reapplied to reach the desired growth rate. The objective of this study was to evaluate the effects of time between rainfall and application of either mepiquat chloride or chlormequat chloride to cotton on plant growth, as well as, estimate the need for PGR reapplication. Cotton was grown in 12-L pots with soil in a greenhouse. PGRs were applied forty days after seedling emergence, when 50% of plants had one pinhead square. Rainfall was simulated 1, 2, 4, 6, or 24 h after spraying. Plant height was measured just before PGR application and then at 3-d intervals for 30 d. At harvest, the number of reproductive branches and structures were counted before dry matter phytomass determination. Both growth regulators reduced cotton dry matter yields regardless of rainfall interval. PGRs controlled excessive plant growth; however, their efficiency was reduced as the time elapsed until rainfall was shorter. Product losses were detected after all rainfall intervals, which, in field conditions would require PGR reapplication. Mepiquat chloride rates to be reapplied after rain were on average 17% higher than chlormequat chloride rates.

Partitioning of Biomass in Well‐Watered and Water‐Stressed Cotton Plants Treated with Mepiquat Chloride

Crop Science ◽  
1991 ◽  
Vol 31 (5) ◽  
pp. 1224-1228 ◽  
Author(s):  
C. J. Fernández ◽  
J. T. Cothren ◽  
K. J. McInnes
Keyword(s):  
Mepiquat Chloride ◽  
Cotton Plants
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