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

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.

1991 ◽  
Vol 5 (3) ◽  
pp. 607-611 ◽  
Author(s):  
B. Jack Johnson ◽  
Tim R. Murphy

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.


2008 ◽  
Vol 38 (3) ◽  
pp. 665-671 ◽  
Author(s):  
Isolina Maria Leite de Almeida ◽  
Elizabeth Orika Ono ◽  
João Domingos Rodrigues

This research evaluated the effects of auxins and gibberellins applied at pre-harvest on the quality of orange juice. Orange trees, Citrus sinensis Osbeck, cv. 'Pêra' were sprayed in three applications, at 45-day intervals, with the following treatments: GA3 + 2,4-D at 12.5mg L-1 each; GA3 + 2,4-D at 25mg L-1; GA3 + 2,4-D at 37.5mg L-1; GA3 + NAA at 12.5mg L-1; GA3 + NAA at 25mg L-1; GA3 + NAA at 37.5mg L-1; NAA + 2,4-D at 12.5mg L-1; NAA + 2,4-D at 25mg L-1; NAA + 2,4-D at 37.5mg L-1, and a control. The treatments did not change juice quality, and showed no plant growth regulator residues 110 days after the last application in every case below 0.05mg L-1.


1990 ◽  
Vol 4 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Belly J. Johnson

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.


2021 ◽  
Vol 39 (2) ◽  
pp. 62-67
Author(s):  
Sean J. Markovic ◽  
James E. Klett

Abstract Moroccan pincushion (Pterocephalus depressus) is a drought-tolerant perennial that is being used in landscapes throughout arid areas of the western United States. This paper describes two experiments researching vegetative cutting production from stock plants. Moroccan pincushion stock plants received foliar applications of gibberellic acid (GA3), benzyladenine, ethephon, or auxin [indole-3-butyric acid (IBA)] plant growth regulators (PGR). Plant growth regulators were applied singularly and in combination with GA3 to determine efficacy on stock plant growth. A propagation study was conducted simultaneously to determine effects of these different PGR treatments applied to stock plants on the rooting of moroccan pincushion cuttings. The stock plant study showed GA3 + benzyladenine application increased cutting production over other PGR treatments. Fresh weight of moroccan pincushion cuttings did not differ among treatments. While cuttings did not differ in dry weight in experiment 1, statistical differences were observed in experiment 2. However, these differences in dry weight did not affect the quality of the cuttings. Cuttings from stock plants treated with GA3 + IBA treatment had the highest numerical growth index [(height + width + width)/3]. Cuttings from stock plants treated with GA3 alone or in combination with another PGR were all greater in average growth index and statistically differed from those without GA3 being applied. PGR treatments did not affect rooting percentages of the cuttings with nontreated stock plant cuttings successfully rooting at an average rate of 95%. However, GA3 + IBA was the only treatment where cuttings had 100% rooting for both experiments, indicating potential rooting benefits. Index words: Plant growth regulator, propagation, Pterocephalus depressus, vegetative cuttings. Species used in this study: Moroccan pincushion [Pterocephalus depressus Archibald]. Chemicals used in this study: gibberellic acid (GA3), benzyladenine, ethephon, indole-3-butyric acid (IBA).


2014 ◽  
Vol 24 (3) ◽  
pp. 313-317
Author(s):  
Rachael E. Pepin ◽  
Janet C. Cole

Summer and fall studies investigated the control of growth of bee balm (Monarda didyma ‘Marshall’s Delight’) by paclobutrazol, uniconazole, or flurprimidol applied to the substrate as a surface drench or through subirrigation. Flurprimidol and uniconazole were applied at 0, 0.5, 1.0, 1.5, or 2.0 ppm (0, 0.09, 0.18, 0.27, or 2.0 mg/pot), while paclobutrazol was applied at 0, 2, 4, 6, or 8 ppm (0, 0.6, 1.2, 1.8, or 2.4 mg/pot). Substrate drench applications were more effective than applications through subirrigation at reducing plant growth. Few trends in application concentrations within plant growth regulator occurred for the plant parameters measured. Based on inconsistent plant responses between the two studies and few differences among application concentrations, we do not recommend any of these plant growth regulators for controlling plant size of bee balm during production without further testing in production environments specific to bee balm.


EDIS ◽  
2009 ◽  
Vol 2009 (4) ◽  
Author(s):  
Frederick M. Fishel

Revised! PI-102, a 5-page fact sheet by Frederick M. Fishel, defines the term, “plant growth regulator,” addresses patterns of use for plant growth regulators, and provides a listing of plant growth regulators registered for use in Florida. Published by the UF Department of Agronomy, April 2009. Revised January 2015 and February 2018. Retired from active collection, February 11, 2021.   Previous version: Fishel, Frederick. 2006. “Plant Growth Regulators”. EDIS 2006 (6). https://doi.org/10.32473/edis-pi139-2006.


1989 ◽  
Vol 3 (2) ◽  
pp. 408-413 ◽  
Author(s):  
Billy J. Johnson

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.


1999 ◽  
Vol 13 (1) ◽  
pp. 132-138 ◽  
Author(s):  
David B. Lowe ◽  
Ted Whitwell

Growth-regulating characteristics of trinexapac-ethyl, paclobutrazol, and flurprimidol were investigated on ‘Tifway’ bermudagrass and four turfgrass weeds (large crabgrass, goosegrass, bahiagrass, and purple nutsedge). All treatments reduced the height of Tifway bermudagrass (25 to 37%) and large crabgrass (14 to 34%), but the height of purple nutsedge, goosegrass, and bahiagrass was not consistently changed. In 1995, all rates of trinexapac-ethyl reduced clipping weights of Tifway bermudagrass (70 to 87%) and bahiagrass (53 to 59%) more than large crabgrass, goosegrass, or purple nutsedge (< 39%). Trinexapac-ethyl (0.4 kg ai/ha) and paclobutrazol (1.1 kg ai/ha) applications increased both large crabgrass clipping weight and canopy visible density. Increased large crabgrass density was attributed to greater tiller numbers with trinexapac-ethyl (60 tillers/pot) and paclobutrazol (63 tillers/pot) compared to untreated large crabgrass plants (53 tillers/pot). Weed growth was not suppressed as much as Tifway bermudagrass growth; therefore, turfgrass stands may be adversely affected by plant growth regulator use under weedy conditions.


2017 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Isna Tustiyani

Kopi merupakan salah satu komoditas perkebunan unggulan nasional. Pembibitan kopi umumnya melalui biji, padahal kopi dapat dibudidayakan melalui cara vegetative yaitu stek asal diberi perlakuan at pengatur tumbuh. Tujuan penelitian  ini adalah untuk  mempelajari pengaruh pemberian berbagai zat pengatur tumbuh alami pada stek kopi. Percobaan dilaksanakan di Kebun Percobaan  Fakultas Pertanian, Universitas Garut pada Oktober – November 2016 menggunakan Rancangan Acak Kelompok (RAK) dengan perlakuan tanpa pemberian ZPT, growtone, ekstrak bawang merah, dan air kelapa. Hasil percobaan dapat disimpulkan bahwa pemberian ekstrak bawang merah dapat menumbuhkan sebesar 50% dan penggunaan growtone sebesar 55% stek kopi hidup.KATA KUNCI: auksin, air kelapa, ekstrak bawang merah,  stek kopi  THE EFFECT OF VARIOUS NATURAL PLANT GROWTH REGULATOR ON GROWTH CUTTINGS OF COFFEEABSTRACTThe Coffee is one of national excellent commodities. The Nurseries of coffee generally through the beans, but it can be grown through vegetative through by cuttings treated with growth regulators. The purpose of this research was to study the effect of various naturally plant growth regulators in coffee cuttings. The experiment was conducted at the Experimental Farm, Faculty of Agriculture, University of Garut in October-November, 2016 using Randomized Complete Block Design with treatment  without giving plant growth regulator, growtone, onion extract, and coconut water. The result showed  that the extract of onion can grow at 50% and the growtone treatments  can grow 55% of the coffee cuttings. 


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