Roles of endogenous and exogenous growth regulators in dormancy of Utricularia vulgaris

1979 ◽  
Vol 57 (24) ◽  
pp. 2750-2759 ◽  
Author(s):  
Robert D. Winston ◽  
Paul R. Gorham
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Environmental Conditions ◽  
Vegetative Growth ◽  
Developmental Stages ◽  
Soybean Callus ◽  
Exogenous Growth ◽  
Endogenous Growth Regulator ◽  
Utricularia Vulgaris

The roles of endogenous and exogenous growth regulators on dormancy control of Utricularia vulgaris were investigated by extraction and bioassay of endogenous levels of four classes at various developmental stages and by measuring the effects of synthetic regulators on these stages. The bioassays used were oat coleoptile for auxins, abscisic acid and other inhibitors; lettuce hypocotyl for gibberellins; and soybean callus for cytokinins. Two weeks before turion formation and during innate dormancy abscisic acidlike and bound gibberellinlike levels were high while free gibberellinlike and auxinlike levels were low. Abscisic acid exogenously applied to actively growing plants rapidly induced turion formation even under noninductive environmental conditions. Kinetin rapidly and completely caused sprouting in innately dormant turions but would not promote continued vegetative growth. These plants formed new turions within 2 weeks of sprouting. During imposed dormancy, when turions rapidly sprouted, there was a low level of abscisic acidlike inhibitor and high levels of gibberellinlike and auxinlike compounds. Turions collected during this state could be maintained in a dormant condition by incubation with abscisic acid even at high temperatures which normally induce sprouting. During sprouting the endogenous growth regulator pattern was similar to that described for imposed dormancy. A model of the environmental and growth regulator factors which control dormancy is presented.

scholarly journals Doses and Times of Trinexapac-ethyl Application in Soybean Development and Yield

2019 ◽  
Vol 11 (14) ◽  
pp. 234
Author(s):  
L. Z. de S. Sales ◽  
E. Lazarini ◽  
I. R. Sanches ◽  
J. W. Bossolani ◽  
F. L. dos Santos ◽  
...  
Keyword(s):  
Experimental Design ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Phenological Stage ◽  
Phenological Stages ◽  
Agronomic Characteristics

The intense vegetative growth is one of the problems faced by soybean producers, causing the lodging, making difficult and damaging the harvest and, even, the efficiency of the application of agricultural defenses. The use of growth regulators is an important tool in the management of growth, in addition, it can favor the transport of photoassimilates for grain filling. Therefore, the objective was to evaluate the best dose and time of trinexapac-ethyl application in the development and yield of soybean varieties. The experiment was conducted in the Selvíria County, Brazil (20°20′53″ S, 51°24′02″ W). The experimental design was used in randomized blocks with treatments arranged in a factorial scheme 5 x 3 (doses x times), with four replications. The varieties used were the BRS Valiosa RR and the BMX Potência RR, the doses of the growth regulator were 0; 50; 100; 200 and 400 g ha-1 of trinexapac-ethyl (Moddus®) and the application times were at the phenological stages V7, V10 and R2. The varieties BRS Valiosa and BMX Potência, respectively, were obtained at the phenological stage V10, with application of 200 g ha-1 of trinexapac-ethyl, greater dry matter accumulation of leaves and pods. Nevertheless, the same did not act on the foliar area of the BRS Valiosa RR variety in the same way that it did not induce changes in the production components of the BMX Potência RR variety. Regardless of the application period (V7, V10 and R2) and the dose (up to 400 g ha-1), the application of trinexapac-ethyl was not a management capable of influencing the agronomic characteristics and the lodging of the plants in both varieties.

Response of Tall Fescue (Festuca arundinacea) to Plant Growth Regulator Application Dates

1989 ◽  
Vol 3 (2) ◽  
pp. 408-413 ◽  
Author(s):  
Billy J. Johnson
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Tall Fescue ◽  
Rapid Growth ◽  
Vegetative Growth ◽  
Festuca Arundinacea ◽  
Plant Growth Regulator ◽  
Growth Cycle ◽  
Application Date

Mon 4620 at 2.8 kg ai/ha, paclobutrazol plus mefluidide at 1.1 plus 0.4 kg ai/ha, and flurprimidol plus mefluidide at 1.1 plus 0.4 kg ai/ha were applied on four dates to determine their influence on highly maintained tall fescue turf. Seedhead suppression was good to excellent by Mon 4620 applied March 1 or 18 and by paclobutrazol plus mefluidide and flurprimidol plus mefluidide applied anytime from March 1 until April 1. None of the plant growth regulators (PGRs) suppressed seedheads effectively when applied April 15 when the grass was near the end of the rapid growth cycle and just before seedhead emergence. Vegetative growth of mowed tall fescue was suppressed for 8 weeks in 1987 when PGRs were applied March 1 immediately after full green-up. Application dates were not as important in 1988 as in 1987. Tall fescue was injured the least by Mon 4620 applied in March and by flurprimidol plus mefluidide applied on March 18. Paclobutrazol plus mefluidide injured the turf severely regardless of application date.

scholarly journals Type and Rate of Plant Growth Regulator Influence Vegetative, Floral Growth, and Quality of Little Lime™ Hydrangea

2013 ◽  
Vol 23 (3) ◽  
pp. 306-311 ◽  
Author(s):  
Diana R. Cochran ◽  
Amy Fulcher
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Vegetative Growth ◽  
Plant Growth Regulator ◽  
Water Control ◽  
Flower Number ◽  
Branch Number

The objective of these experiments was to evaluate the response of Little Lime™ hardy hydrangea (Hydrangea paniculata ‘Jane’) across two seasons in response to single foliar applications of three plant growth regulators (PGRs) at two rates: dikegulac sodium at 800 or 1600 ppm, benzyladenine at 300 or 600 ppm, or ethephon at 500 or 1000 ppm. There were two additional treatments: a hand-pruned control leaving three nodes and an unpruned water control (untreated) applied the same day as the PGR applications. To evaluate PGR efficacy, vegetative growth, floral attributes, branch symmetry, and phytotoxicity were assessed. Dikegulac sodium significantly increased branch number (BN) compared with all other treatments. Branch symmetry was greater in dikegulac sodium (800 or 1600 ppm) and hand-pruned treatments compared with the untreated and other PGR treatments (2011 and 2012). Flower number was greater in all PGR treatments compared with hand-pruned plants (2011 and 2012). The only treatment that promoted more symmetrical branching without reducing flower count was dikegulac sodium (800 or 1600 ppm). Phytotoxicity was observed in both seasons; however, no injury symptoms were evident 16 weeks after treatment (WAT), the termination of the experiment.

Sequential Herbicide and Plant Growth Regulator Treatments on Bermudagrass (Cynodonspp.)

1991 ◽  
Vol 5 (3) ◽  
pp. 607-611 ◽  
Author(s):  
B. Jack Johnson ◽  
Tim R. Murphy
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Vegetative Growth ◽  
Plant Growth Regulator ◽  
Growth Suppression

Sequential applications of MSMA plus metribuzin with selected plant growth regulators interacted synergistically and increased injury of ‘Tifway’ bermudagrass 1 and 2 wk after treatment. However, the higher injury at 3 wk after treatment, from sequential MSMA plus metribuzin with flurprimidol plus mefluidide or paclobutrazol with mefluidide, was additive. The vegetative growth suppression of bermudagrass at 2 wk after treatment with 2,4-D plus mecoprop plus dicamba with flurprimidol was antagonistic. The higher growth suppression 2 wk after treatment for MSMA plus metribuzin and flurprimidol plus mefluidide was additive compared to flurprimidol with mefluidide alone.

Response of Bermudagrass (Cynodon spp.) Cultivars to Multiple Plant Growth Regulator Treatments

1990 ◽  
Vol 4 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Belly J. Johnson
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Vegetative Growth ◽  
Plant Growth Regulator ◽  
Severe Injury ◽  
Severely Injured ◽  
Common Bermudagrass ◽  
Better Than

Plant growth regulators were evaluated on common and African ‘Tifway’ bermudagrass. Flurprimidol plus mefluidide applied at 1.1 plus 0.14 kg ha-1 and followed by 0.56 plus 0.14 kg ha-1 at 2- to 3-week interval suppressed vegetative growth of mowed common bermudagrass for 5 wk (17 to 23%) and unmowed turf for 6 wk (40%), but severely injured the turf. The injury ranged from 25 to 32% from 2 to 6 wk after treatment. The plant growth regulators that injured common bermudagrass less than flurprimidol plus mefluidide did not suppress the mowed turf for as long a period. Vegetative growth of common bermudagrass not mowed was suppressed for 6 wk when treated once with flurprimidol plus mefluidide and twice with flurprimidol, mefluidide, imazethapyr, paclobutrazol (1.1 plus 1.1 kg ha-1), and paclobutrazol plus mefluidide. Of the plant growth regulators evaluated, only imazethapyr suppressed common bermudagrass seedheads. The suppression was 70% for 4 wk, but reduced to <70% by 5 wk. Paclobutrazol applied initially at 1.1 kg ha-1 and followed at 0.56 kg ha-1 suppressed vegetative growth of mowed Tifway bermudagrass for 5 wk and unmowed turf for 8 wk without causing severe injury. The suppression of mowed Tifway bermudagrass with two applications of paclobutrazol was as good or better than with any other plant growth regulator. All plant growth regulators suppressed vegetative growth of unmowed Tifway bermudagrass for 8 wk.

Effect of applied growth regulators on cone production in Douglas-fir, and relation of endogenous growth regulators to cone production capacity

1980 ◽  
Vol 10 (3) ◽  
pp. 405-414 ◽  
Author(s):  
E. E. McMullan
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Production Capacity ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Female Cone ◽  
Cone Production ◽  
Male Cone ◽  
Stage Of Development

Extracts of buds and young shoots of a good cone-producing clone of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were tested for cone production effect on seed orchard Douglas-fir trees chosen for their history of poor cone production. Other metabolites, including gibberellin 4/7, arginine, and abscisic acid were also tested. Growth regulator levels in good and poor cone-producing clones of Douglas-fir were compared over the period of bud break and shoot elongation.No evidence was obtained for the presence of growth regulators critical to cone production in purified extracts from ramets of the good cone-producing clone. Applied gibberellin 4/7 increased male and female cone production. Crude extracts of a good cone-producing clone increased male cone bud production. Arginine and abscisic acid had no effect.Bioassays indicated that growth regulator levels in buds and young shoots changed greatly with stage of development but were similar in good and poor cone-producing clones.

scholarly journals Evaluation of Chlorimuron as a Growth Regulator for Peanut

1995 ◽  
Vol 22 (1) ◽  
pp. 62-66 ◽  
Author(s):  
Wayne E. Mitchem ◽  
Alan C. York ◽  
Roger B. Batts
Keyword(s):  
Growth Regulator ◽  
Vegetative Growth ◽  
Lateral Branch ◽  
Internode Length ◽  
Main Stem ◽  
Stem Length ◽  
Vine Growth

Abstract Chlorimuron was evaluated as a growth regulator on peanut. Treatments included chlorimuron at a total of 8.8 g ai/ha applied once at 60,75, or 90 d after emergence (DAE) or in equal portions applied twice at 60 and 75, 60 and 90, or 75 and 90 DAE or three times at 60, 75, and 90 DAE. Daminozide at 950 g ai/ha applied 75 DAE was included as a comparison. In a year with excessive vine growth, daminozide and all chlorimuron treatments except 8.8 g/ha applied 90 DAE reduced cotyledonary lateral branch and main stem length at harvest 9 to 20 and 12 to 24%, respectively, due to suppression of internode length. Sequential applications of chlorimuron generally suppressed growth more than single applications. No improvement in row visibility at harvest was noted. In a dry year with limited vegetative growth, neither chlorimuron nor daminozide affected cotyledonary lateral branch or main stem length at harvest. Chlorimuron at 2.9 g/ha applied 60, 75, and 90 DAE reduced yield 18% at one of four locations; no other treatment affected yield. Chlorimuron at 8.8 g/ha applied 60 DAE or 4.4 g/ha applied 60 and 75 DAE reduced the percentage of fancy pods and extra large kernels at one or more locations. No treatment affected the percentage of total sound mature kernels. Results suggest chlorimuron has little to no potential for use as a growth regulator.

The role of exogenous plant regulators in the dormancy of onion bulbs

1974 ◽  
Vol 82 (1) ◽  
pp. 113-116 ◽  
Author(s):  
M. Abdel-Rahman ◽  
F. M. R. Isenberg
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Maleic Hydrazide ◽  
Rest Period ◽  
Storage Period ◽  
Inhibitory Effect ◽  
Onion Bulbs ◽  
Subsequent Application

SUMMARYExperiments were conducted to study the effect of plant injection with growth regulators on the dormancy of onion bulbs cv. Elba Globe. Application of abscisic acid induced early senescence of the leaves and prolonged the rest period of the bulbs. This effect was partially overcome by subsequent applications of gibberellin, auxin or cytokinin and totally overcome with the application of a mixture of the three hormones. Maleic hydrazide application prolonged the rest period by inhibiting both sprouting and rooting of the bulbs throughout the storage period. This inhibitory effect was not overcome by the subsequent application of auxin, gibberellin, kinetin, or their combinations. Ethephon application increased rooting of bulbs and partially overcame the effect of abscisic acid on dormancy.

scholarly journals Action of growth regulators on production of soybean cultivar Davis

1981 ◽  
Vol 38 (1) ◽  
pp. 127-138 ◽  
Author(s):  
Paulo R.C. Castro ◽  
Roberto S. Moraes
Keyword(s):  
Glycine Max ◽  
Gibberellic Acid ◽  
Growth Regulators ◽  
Seed Weight ◽  
Dry Weight ◽  
Soybean Plant ◽  
Trimethylammonium Chloride ◽  
Seed Number ◽  
Exogenous Growth ◽  
Soybean Plants

This research deals with the effects of exogenous growth regulators on production of soybean plant (Glycine max cv.. Davis) under greenhouse conditions, At the flower anthesis, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm was applied. Other two applications with TiBA, with intervals of four days, were realized. Before flowering, Agrostemin (1 g/10 ml/3 1), gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm were applied. It was observed that CCC and TIBA reduced stem dry weight. Soybean plants treated with TIBA reduced weight of pods without seeds , seed number and seed weight.

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