Plant Growth Regulator Update
Stay current on the latest developments in plant growth regulators and strategies.
June 20, 2008
To help you finish up poinsettia production and move into spring, we've asked the leading technical people at companies who market plant growth regulators (PGR) to keep us current on the latest product developments and strategies.
OHP recently acquired the specialty product line from Chemtura Corp., which includes B-Nine WSG and Paczol. "Both are long-time proven PGRs and have a proven track record for delivering growth control and improved crop qualities," says OHP's Technical Services Manager David Barcel. "These two materials, combined with the OHP brand Cycocel, will provide growers with most all of their growth control needs for greenhouse and nursery crops."
Fine Americas has added another PGR, Configure, to its arsenal. Configure increases lateral/basal branching and promotes flowering in certain ornamental crops and reduces overall plant height. The active ingredient is N-(phenylmethyl)-1H-6-amine. It is registered for use on:
- Christmas cactus (schlumbergera) to promote vegetative branching and increase number of flower buds under reproductive conditions
- Plantain lily (hosta) to promote lateral growth of finished plants by inducing the outgrowth of axillary and rhizomic buds and to increase offsets during propagation
- Purple coneflower (echinacea) to increase the number of branches.
Ball Controlled Growth seed treated with A-Rest through a partnership with SePRO has been very well received by growers this first year, says Jayson Force, Ball's senior product manager for seed. "Ball Controlled Growth has certainly exceeded expectations in its first year," he says. "The biggest complaint from growers was that there weren't enough varieties in the program, so next year we'll have about 450 varieties available as Ball Controlled Growth seed. The message and usefulness of the product really seems to resonate with growers."
Crops available for treatment include ageratum, dianthus, impatiens, marigolds, ornamental millet, pansies, petunias and zinnias. A-Rest is added during the coating or pelleting process, which provides consistent early growth control to prevent seedling stretch. Growers can reduce their costs by skipping the first one or two PGR applications.
In The Pipeline
OHP is working with a compound that has been shown to increase lateral branch development. "In the Pacific Northwest, fruit tree work has been very positive, as well as many ornamental woody plants," Barcel says. "Though still under development with Bayer AG, OHP has plans to develop rates and timing for woody and herbaceous crops."
David Ross, Syngenta's technical manager for lawn and garden, reports that Primo, which is used in turf grass management, will be able to be used on ornamental grasses in the future. "We're hoping to add ornamental grasses to the label next season," he says.
Research & Technical Support
Valent reports no changes to the Fascination, Sumagic and ProGibb labels, although research is in the works.
"Our information for completed university research trials is limited at this time, however our university research partners continue to work with us on trials and research to discover new ways growers can use these products to better manage plant growth and produce marketable crops," says Jason Fausey, Valent's field market development specialist. "We look forward to continuing to work with the growers to help them maximize the benefits from our plant growth regulators."
Fausey suggests growers take a closer look at late-season Sumagic drench applications for a variety of plant material. "Sumagic has shown to effectively reduce unwanted plant stretch in some of the most aggressive plant material, even when applied at low rates," he says. "Low-rate drenches of Sumagic are a simple and cost-effective way to better manage plant growth. Additionally, drenches provide flexibility over spray applications, as they can be applied later in the crop's development and have less of an impact on potentially decreasing flower size."
OHP reports poinsettias continue to be a key crop for research. "Recent research has suggested the opportunity to produce a poinsettia crop using very low drench dose rates of Paczol (1/10 ppm) starting in early September and can be applied as needed to maintain crop height per the poinsettia growth curve model," Barcel says. "This can be a particularly useful tool for large operations or growers able to chemigate their crop."
OHP has launched a new Web site called PGRx for prescription growth control information. Growers can log onto www.pgrx.info and access decades of academic and in-house research. "Listed rates give growers a starting ppm rate from which they can adjust to fit their specific growing needs," Barcel says.
He also offers poinsettia production tips. "Regardless of locations, poinsettias should not receive foliar spray applications of B-Nine after the initiation of short days," Barcel says. "As a guide, no later than Oct. 1 outside of Florida or after Oct. 25 in Florida. Cycocel can offer a slightly longer window of use, such as Oct. 15 for northern growers having hot and sunny growing conditions, or Oct. 21 for the same conditions in the South. Once November appears, many growers will use a late-season drench of Paczol (Paclobutrazol) at a general rate of ½ ppm to slow down late-season stretch or to hold the crop. The rate depends on your growing conditions and poinsettia variety."
Syngenta continues to work with Jim Barrett at the University of Florida and other leading universities to identify new opportunities, uses and application methods for Bonzi. Barrett also hosts a Web site (http://hort.ifas.ufl.edu/floriculture/height2007/) that helps growers with poinsettia crop management. "He grows five varieties of poinsettias as a grower would, but according to his management practices," Ross explains. "This gives growers an opportunity to compare their crops to his and see if they're on track or falling behind. It's a positive check, something to compare a crop to."
Syngenta also has published crop-specific guides for key crops, like pansies and poinsettias, which cover managing insects and diseases, as well as plant growth. "Syngenta prides itself on not just giving growers another jug of product," Ross says. "We have a new initiative in plant health and are looking at the market more holistically. With the recent acquisitions of Fafard and Fischer, we're looking at plants and how they interact with chemicals, media and beneficials. We have a much bigger role in ornamentals production in general."