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

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.

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

Journal of Agricultural Science ◽

10.5539/jas.v9n12p122 ◽

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.

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Growth regulator losses from cotton plants due to rainfall

Scientia Agricola ◽

10.1590/s0103-90162010000200005 ◽

2010 ◽

Vol 67 (2) ◽

pp. 158-163 ◽

Cited By ~ 1

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.

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

Crop Science ◽

10.2135/cropsci1991.0011183x003100050029x ◽

1991 ◽

Vol 31 (5) ◽

pp. 1224-1228 ◽

Cited By ~ 18

Author(s):

C. J. Fernández ◽

J. T. Cothren ◽

K. J. McInnes

Keyword(s):

Mepiquat Chloride ◽

Cotton Plants

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Effect of high doses of Mepiquat chloride (pix) on Egyptian cotton productivity under North Delta conditions: تأثير التركيزات العالية من كلوريد الميبكويت (البكس) على إنتاجية نباتات القطن المصري تحت ظروف شمال الدلتا

Journal of agricultural, environmental and veterinary sciences - مجلة العلوم الزراعية والبيئية والبيطرية ◽

10.26389/ajsrp.m060519 ◽

2019 ◽

Vol 3 (4) ◽

Author(s):

Amany Ahmed Elashmouny, Mohamed Kotb Elkashlan, Youssef Fath

Keyword(s):

Growth Rate ◽

Field Experiments ◽

Block Design ◽

Mepiquat Chloride ◽

Plant Seed ◽

Cotton Plants ◽

Absolute Growth ◽

High Doses ◽

In The Beginning ◽

Egyptian Cotton

Two field experiments were conducted during 2017 and 2018 seasons to study the effect of high doses of mepiquat chloride at rates of 0, 1, 1.5 and 2 liter/ fed on growth, phytohormones and yield of cotton plants cv. Giza 94. The experiment was conducted in Sakha, Kafr El-Shiekh Governorate, Egypt in a randomized complete block design. In the beginning of square and after 15 days from squaring, the cotton cultivars were foliar sprayed by with different doses of pix. Short internodes of 5 to 7 cm observed in spraying of different concentration of pix, while long internodes below 10 cm developed in control. As a conclusion, the results showed that, in general spraying mepiquat chloride (pix) had a significant effect on the growth of cotton plants i.e, reduction of plant height, absolute growth rate and concentration percentage of Gibberellins in cotton plants. On the other hand, spraying cotton plants with pix using 1 liter/ fed. significantly increased crop growth rate, photosynthesis pigments, number of open bolls/ plant, seed cotton yield/ Fadden compared with control and other doses.

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