scholarly journals Development of New Plant Growth Regulators from a University Perspective

2002 ◽  
Vol 12 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Duane W. Greene
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Evaluation Process ◽  
Major Change ◽  
Negative Effects ◽  
Quality Product ◽  
Critical Components ◽  
High Quality Product ◽  
Profit Potential

Plant growth regulators (PGRs) play an important commercial role in horticulture. Although often expensive, they are generally used on high value crops where the costs can be retrieved through the increased value their usage creates in a given crop. The impetus for development of new PGRs is generally initiated by the agrochemical industry where they perceive a need that has a profit potential, whereas the motivation for the development of a PGR by researchers is largely to aid the industry they serve. University and government researchers initially follow a prescribed protocol early in the development process, but once they have gained personal experience with a PGR, further research is often guided by personal observations and keen technical insight. During the development and evaluation process, university and government researchers are optimistic, and negative effects are generally viewed as challenges, that can and will be overcome. Discussion and effective communication are critical components in the overall development of a new PGR. Researchers generally exchange information very freely, unless restricted from doing so by a nondisclosure or other contract agreement. The underlying goal for university and government researchers is to get approval of a new PGR product and/or use that will allow growers to produce a high quality product for consumers with an improved profit margin for growers. Development of new PGRs is undergoing major change that unfortunately will lead to the development and registration of fewer compounds. There are not as many agrochemical companies, there are a decreasing number of university and government researchers, and diminishing funds available to support the development of new PGRs.

scholarly journals Plant Growth Regulators Modify Fruit Set, Fruit Quality, and Return Bloom in Sweet Cherry

HortScience ◽  
2021 ◽  
pp. 1-10
Author(s):  
Irfan Ali Sabir ◽  
Xunju Liu ◽  
Songtao Jiu ◽  
Matthew Whiting ◽  
Caixi Zhang
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Fruit Quality ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Fruit Set ◽  
Foliar Application ◽  
Negative Effects ◽  
Return Bloom

Sweet cherry (Prunus avium L.) is a valuable fruit crop worldwide. Farmers’ incomes are closely related to fruit quantity and quality, yet these can be highly variable across years. As part of a broader project for optimizing fruit set and fruit quality in sweet cherries, this study was conducted to evaluate the potential of various plant growth regulators (PGRs) for improving fruit set and fruit quality. Cytokinins, gibberellins, auxin, and polyamines were used as treatments. Treatments were applied as foliar sprays at full bloom to ‘Bing’ and three low-productivity genotypes, ‘Regina’, ‘Tieton’, and ‘PC8011-3’. We assessed the fruit set, fruit quality, and return bloom from each treatment. 4-chlorophenoxyacetic acid (4-CPA) increased fruit set by 53% and 36% in ‘Bing’ and ‘Tieton’, respectively. The combination of gibberellin (GA)3 + GA4/7 was more effective for improving fruit set than other isomers of gibberellin alone. Cytokinin treatments had slight adverse effects or no effect on fruit set except for CPPU. In ‘PC8011-3’, both N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) and 4-CPA enhanced fruit set by ≈81% and 100% compared with untreated control. The response of cherry trees to polyamine sprays depended on the properties of the cultivars and the treatment concentration. Foliar application of GA3, GA4/7, or N-phenyl-N'-(1, 2, 3-thiadiazol-5-yl) urea (TDZ) in ‘Bing’ trees has negative effects on return bloom, whereas GA1 can increase the yield and flower buds. These results suggest that PGRs may have varied effects on sweet cherry fruit set and that more work is needed to develop practical programs for improving yield security.

An Entomogenous Nematode Steinernema carpocapsae is Compatible with Potting Media Environments Created by Horticultural Practices

1991 ◽  
Vol 26 (4) ◽  
pp. 390-394 ◽  
Author(s):  
Ronald D. Oetting ◽  
Joyce G. Latimer
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Galleria Mellonella ◽  
Steinernema Carpocapsae ◽  
Pine Bark ◽  
Peat Moss ◽  
Negative Effects ◽  
Significant Difference ◽  
Potting Media

Three experiments were conducted to evaluate the effect of different potting media and horticultural practices on the infectivity of Steinernema carpocapsae (Weiser). Bioassays were conducted with S. carpocapsae added to potting media containing Galleria mellonella (L.) larvae. Potting media tested were aged pine bark, new pine bark, peat moss, aged cow manure, and a peat/vermiculite soilless medium (Pro-Gro 200). The horticultural practices tested were potting media pH level, fertilization, salt level, and application of plant growth regulators. The plant growth regulators ancymidol, paclobutrazol, chlormequat, and daminozide were each applied as a medium drench. The LC50s of the nematodes against G. mellonella, in potting media with different horticultural practices, were all between 0.50 and 2.06 with no significant difference in infectivity. Nematodes could be used for insect control with no negative effects under these growing conditions.

scholarly journals SEQUENCING OF FORCING SOLUTION PLANT GROWTH REGULATORS ENHANCES MACROPROPAGATION OF LIGUSTRUM VULGARE L. BY SOFTWOOD CUTTINGS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 608a-608
Author(s):  
Guochen Yang ◽  
Paul E. Read
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Woody Plants ◽  
Woody Plant ◽  
Shoot Elongation ◽  
Root Number ◽  
Negative Effects ◽  
Rooting Of Cuttings ◽  
Forcing Solution

A forcing solution containing 200 mg 8-hydroxyquinoline citrate per liter and 2% sucrose has been demonstrated to extend the season for obtaining softwood growth suitable for use as explants in micropropagation (Yang & Read 1989). Forcing dormant woody stems in the off-season in this fashion also enhances the macropropagation of woody plant species by providing softwood outgrowth that can be rooted as softwood cuttings. GA3, IBA, IAA and NAA were incorporated into softwood growth which was later used as cuttings for rooting by adding plant growth regulators at various concentrations to the forcing solution. GA3 incorporated into the forcing solution hastened bud break, increased shoot elongation, but inhibited rooting of softwood cuttings taken from stems forced in this manner. IBA, IAA and NAA in the forcing solution exhibited typical auxin effects on rooting of cuttings by increasing root number per cutting and root elongation. In order to expedite macropropagation of woody plants, GA3 and IBA were added SEQUENTIALLY to the forcing solution. Addition of IBA to fresh forcing solution following initial use of GA3 in the forcing solution counteracted the negative effects of GA3 and stimulated rooting. This protocol is proposed as a method to assist propagation in rooting difficult species by softwood cuttings in the off-season.

In Vitro Reproductive Development of Peanut, Arachis hypogaea L., as Influenced by Plant Growth Regulators, Sucrose and pH1

1995 ◽  
Vol 22 (2) ◽  
pp. 135-141
Author(s):  
Q. L. Feng ◽  
H. E. Pattee ◽  
H. T. Stalker
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Embryo Development ◽  
Growth Regulators ◽  
Reproductive Development ◽  
Naphthaleneacetic Acid ◽  
Negative Effects ◽  
Mature Embryos ◽  
High Concentrations

Abstract Research on in vitro embryo culture in Arachis has the objective of rescuing interspecific hybrid embryos which abort before they reach maturity. This study explored effects of the three exogenous plant growth regulators 1-naphthaleneacetic acid (NAA), gibberellic acid (GA3), and 6-benzylaminopurine (6-BAP); sucrose; and medium pH on in vitro fruit and embryo development of A. hypogaea L. by culturing 10-d-old peg tips. Results indicated that medium containing 0.5 to 1.0 mg L-1 NAA was optimal for in vitro pod formation and embryo development. GA3 did not have a significant influence and 6-BAP had negative effects on both in vitro fruit and embryo development. High concentrations of 6-BAP and NAA induced callus which inhibited ovary enlargement and embryo development. Sixty g L-1 sucrose was the best concentration for ovary enlargement and embryo development. Acidic medium was needed for in vitro reproductive development with pH 4.5–6.5 the most favorable. A pod formation frequency of 81%, a seed production rate of 90% (from pods recovered in vitro), and plant recovery of 33% were obtained for a medium containing 1.0 mg L-1 NAA and 0.5 mg L-1 GA plus 60 g L-1 sucrose at pH 5.8. In vitro-recovered cotyledonary embryos between 4 and 10 mm long germinated precociously into seedlings at relatively higher frequencies than morphologically mature embryos which produced more vigorous plants.

Wheat regenerants in the system of rapid assessment of the effect of 24-epibrassinolide

Biomics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 394-397
Author(s):  
Seldimirova O.A. ◽  
M.V. Bezrukova ◽  
N.N. Кruglova ◽  
F.М. Shakirova
Keyword(s):  
Plant Growth ◽  
Experimental Model ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Drought Resistance ◽  
Rapid Assessment ◽  
Immature Embryo ◽  
Model System ◽  
Wheat Cultivars ◽  
Experimental Model System

The influence of 24-epibrassinolide on the efficiency of regenerants obtained from embryonic calli formation was studied in wheat cultivars contrast for drought resistance. The possibility of using the experimental model system «immature embryo – embryonic callus – regenerant» in the rapid assessment of the effect of antistress plant growth regulators is shown.

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