Environmental Horticulture Research Summaries

Pendimethalin has been registered in the United States since 1994 for uses in and around environmental horticulture plants in production nurseries and in landscapes. Between 1981 and 2023,

From 2004 to 2023, IR-4 completed 258 trials on Pennant Magnum (s-metolachlor). The data contained in this report was generated to register uses of s-metolachlor on and around environmental horticulture plants with over-the-top applications.

Flumioxazin has been registered in the United States since 2003 for uses in and around environmental horticulture plants in production nurseries and in landscapes. Between 2000 and 2023, the IR-4 Project has conducted 641 trials using three granular

Ventigra  (afidopyropen) is an insecticide registered by BASF for the control of piercing and sucking insect pests such as aphids, whiteflies, psyllids, scales and leafhoppers.

Avelyo (mefentrifluconazole) is a fungicide developed by BASF that has been registered for use since May 2020. It is used for the control of diseases such as anthracnose, powdery mildew,

Fluopicolide was registered as Adorn 4SC in the United States in 2008 for control of Pythium, Phytophthora and downy mildew in environmental horticulture plants. State registrations in California and New York occurred in 2010 and 2011, respectively.

Triticonazole was registered as Trinity 2SC in the United States in 2007 as a turf fungicide. Trinity SC was expanded to diseases of environmental horticulture diseases in 2013. Because triticonazole is in the triazole class,

Oxathiapiprolin was registered as Segovis in the United States in 2017 for disease control on ornamental horticulture plants in greenhouse and nurseries. The commercial label contains a general list

From 2007 to 2023, IR-4 completed 726 trials on Freehand 1.75G (BAS 659 G; dimethenamid-p + pendimethalin). The data contained in this report was generated to register uses of dimethenamid-p + pendimethalin on and around environmental

SP1770 is a new herbicide being developed by SePro. The IR-4 Project completed 41 crop safety trials on 29 environmental horticulture plant species orgenera during 2016 to 2019.

Prodiamine + Isoxaben (Gemini G) is a herbicide combination developed by ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf weeds on environmental horticulture crops.

From 2007 to 2021, IR-4 completed 594 trials on Tower EC (dimethenamid-p). The data contained in this report was generated to register uses of dimethenamid-p on and around environmental horticulture plants

Postiva (pydiflumetofen + difenoconazole) is a new fungicide registered by Syngenta for the control of foliar diseases of environmental horticulture crops. The IR-4 Project completed 43 crop safety trials

Picarbutrazox is a novel fungicide with a new mode of action being developed by Nisso America for the control of oomycete diseases such as Bremia, Peronospora, Pseudoperonospora, Phytophthora,

Flutianil is a new fungicide being developed by Nichino for the control of powdery mildew on environmental horticulture crops. The IR-4 Project completed 36 crop safety trials on 15 environmental

Abamectin has been registered since 1987 for environmental horticulture crops, initially for leafminers and spider mites on annuals and herbaceous perennials. Then in 2000, woody ornamentals plus aphids,

From 2004 to 2022, IR-4 completed 231 trials on Pennant Magnum (s-metolachlor). The data contained in this report was generated to register uses of s-metolachlor on and around environmental horticulture plants

SP2478 is a new fungicide being developed by SePro for the control of diseases on environmental horticulture crops such as powdery mildew and other diseases. The IR-4 Project completed

Fortress (isoxaben + dithiopyr) was registered in 2018 for environmental horticulture crop uses. Between 2018 and 2020, IR-4 examined 17 crop species / genera to expand this label to

Avelyo (mefentrifluconazole) is a fungicide developed by BASF that has been registered for use since May 2020. It is used for the control of diseases such as anthracnose, powdery mildew,

XDE-659 is a new fungicide being developed by Corteva for the control of Botrytis gray mold, powdery mildew and other foliar pathogens of environmental horticulture crops. The IR-4 Project completed 20

Fuerte (flumioxazin + prodiamine) has been registered in the United States since 2018. Starting in 2020, the IR-4 Project has been screening additional crops for their tolerance to over the top applications.

Prodiamine + Isoxaben (Gemini G) is a herbicide combination developed by Everris dba ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf weeds on environmental horticulture crops.

ANEEM (neem oil + azadirachtin) is an extract from the neem plant which has insecticidal, miticidal and some nematicidal and fungicidal properties. The IR-4 Project completed 23 crop safety trials on seven

TDA-01 is a new active ingredient for foliar plant pathogens such as bacteria. The IR-4 Project has screened 3 different formulations, completing 28 crop safety trials on 9 environmental horticulture plant species or genera from 2017 through 2021. The first two formulations caused moderate to

Broadform SC (fluopyram + trifloxystrobin) is a new fungicide for foliar plant pathogens such as leaf spots, powdery mildew, and rust. The IR-4 Project completed 24 crop safety trials on 14 environmental horticulture

Dimension was initially registered in 1992 for environmental horticulture uses. This initial label contained an extensive list of plants for landscapes where Dimension could be used without causing phytotoxicity.

Oxadiazon has been registered in the United States since the 1970’s for uses in and around environmental horticulture plants in production nurseries and in landscapes. Between 1972 and 2021, the IR-4 Project has conducted

From 2004 to 2021, IR-4 completed 196 trials on Pennant Magnum (s-metolachlor). The data contained in this report was generated to register uses of s-metolachlor on and around environmental horticulture plants

From 2007 to 2021, IR-4 completed 573 trials on Tower EC (dimethenamid-p). The data contained in this report was generated to register uses of dimethenamid-p on and around environmental horticulture plants

From 2011 through 2021, IR-4 has completed 186 trials evaluating two granular and one liquid formulations of indaziflam for crop safety. The data contained in this report was generated to register the use of indaziflam

Basagran T/O has been registered for several years as a directed application and as an over-the-top application on limited plant species. However, growers have expressed the need to have additional plants added for over-the-top applications.

Lontrel (clopyralid) was initially registered in 1998 for environmental horticulture uses. This initial label contained an extensive list of environmental horticulture plants where Lontrel could be used without causing phytotoxicity.

F6123 is a fungicide being developed by FMC for the control of diseases on environmental horticulture crops such as anthracnose, powdery mildew, black spot, rusts, leaf spots and other foliar diseases.

Avelyo (mefentrifluconazole) is a fungicide developed by BASF that has been registered for use since May 2020. It is used for the control of diseases such as anthracnose, powdery mildew,

SP2700 is a new fungicide being developed by SePro for the control of diseases on environmental horticulture crops such as Alternaria, Cylindrocladium, Fusarium, Rhizoctonia, and Thielaviopsis.

Fiesta (Iron HEDTA) is a new herbicide currently labeled for post emergence broadleaf weed control on lawns (use on rights of way or non-crop areas), turf, golf courses, parks, playgrounds, cemeteries and athletic fields.

V-10433 is a new insecticide being developed by Valent for the control of scales, mealybugs thrips and other insect infesting environmental horticulture crops. The IR-4 Project completed 24 crop safety trials

Mandestrobin is a new systemic and translaminar fungicide being developed by Valent for the control of Botrytis and other foliar diseases of environmental horticulture crops. The IR-4 Project completed 37 crop safety trials

ISM-555 is a new insecticide being developed by Syngenta for management of scale, mealybugs, thrips, beetles and other pests on environmental horticulture crops. The IR-4 Project completed 22 crop safety trials

IKF-309 is a new fungicide being developed by ISK for the control of powdery mildew on environmental horticulture crops. The IR-4 Project completed 18 crop safety trials on 12 environmental horticulture plant species

Flutianil is a new fungicide being developed by Nichino for the control of powdery mildew on environmental horticulture crops. The IR-4 Project completed 21 crop safety trials on 12 environmental

SP3014 is a new insecticide being developed by SePro for the control of scales, mealybugs and other insects on environmental horticulture crops. The IR-4 Project completed 22 crop safety trials

Pydiflumetofen + Difenoconazole is a new fungicide being developed for the control of foliar diseases of environmental (aka ornamental) horticulture crops. The IR-4 Project completed

Pydiflumetofen + Fludioxonil is a new fungicide being developed for the control of foliar and soil-borne diseases of environmental (aka ornamental) horticulture crops. The IR-4 Project completed

Fortress (isoxaben + dithiopyr) was registered in 2018 for environmental horticulture crop uses. Between 2018 and 2020, IR-4 examined 17 crop species / genera to expand this label to

Prodiamine has been registered in the United States for many years for uses in and around ornamental plants in production nurseries and in landscapes. There have been several label

Since 1995 IR-4 has completed 373 trials with products containing halosulfuron (Sedgehammer, Manage) on 137 crops. The data contained in this report were

Basagran T/O has been registered for a number of years as a directed application and as an over-the-top application on limited plant species. However, growers have expressed the

Pradia (cyclaniliprole + flonicamid) is a new insecticide combination recently registered for environmental horticultural crops for the control of a wide variety of insects including aphids,

Gallery 75DF (isoxaben) was initially registered in 1992 for ornamental horticulture uses. This initial label contained an extensive list of ornamental horticulture crops where Gallery could be

Since 1996 IR-4 has completed 259 trials with products containing sulfentrazone (Sulfentrazone 0.2G and Dismiss 4F) on 111 crops. The data contained in this report

Fiesta (Iron HEDTA) is a new herbicide currently labeled for post emergence broadleaf weed control on lawns (use on rights of way or non-crop areas), turf, golf courses, parks, playgrounds,

OxiPhos (Mono and di potassium salts of phosphorus acid + hydrogen peroxide) is labeled

Pydiflumetofen is a new fungicide being developed by Syngenta for the control of leaf spots (Septoria, Cercospora, Alternaria, Venturia), powdery mildew,

Indemnify (fluopyram) is a new fungicide being developed by Bayer for the control of nematodes; the current product is only registered for turf uses.

From 2004 to 2012, fenamidone (FenStop, FenStar) was screened through the IR-4 Program as drench or foliar applications for effacay against nine Phytophthora species causing root rots and

The IR-4 Project screens new active ingredients for potential deleterious impacts to aid growers in selection of appropriate disease management tools for their crops. From 2014

Tolfenpyrad was first registered as Hachi-Hachi 15 EC in the United States on July 28, 2010 for the control of aphids, leafhoppers, scales, thrips, whiteflies, and early instar lepidopteran larvae on

Pyrifluquinazon was registered for use on greenhouse ornamental horticulture crops as foliar sprays in the United States in 2013 to manage whiteflies, aphids, leafhoppers, chilli thrips, and

Pyridalyl was registered as Overture for use on environmental horticulture plants in greenhouses with foliar applications in the United States in 2008.

Cyflufenamid is an active ingredient for managing foliar diseases including powdery mildew and botrytis.

Alibi Flora (azoxystrobin + difenoconazole) was registered on January 12, 2015 for use on ornamental horticulture crops and landscape ornamental horticulture plants in

Azoxystrobin was registered as Heritage in the United States in 1997 as a turf fungicide. In April 2003, this label was updated to include applications for certain diseases on environmental horticulture crops.

Prodiamine + Isoxaben (Gemini G) is a new herbicide combination being developed by Everris dba ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf 

Picarbutrazox is a novel fungicide with a new mode of action being developed by Nisso America for the control of oomycete diseases such as Bremia, Peronospora, Pseudoperonospora,

Sultan (cyflumetofen) was registered for use on greenhouse ornamental horticulture crops as foliar sprays in the United States on May 9, 2014 to manage mites. The label does not contain

From 2009 through 2018 IR-4 completed 246 trials evaluating Biathlon (oxyfluorfen + prodiamine) crop safety. The data contained in this report were generated to register uses

Pseudomonas chlororaphis (SP2300, Zio) is a new fungicide being developed by AgBiome and SePro for the control 

Acibenzolar is an active ingredient that stimulates plant defense systems. In 2002, IR-4 started testing Insimmo (acibenzolar) for safety 

IR-4 conducted fifty-one (51) trials evaluating two formulations of flumioxazin + pyroxasulfone: V-10233 76WG (37 trials) and V-10336 61.5WG (14 trials) for crop safety. 

Pydiflumetofen + Fludioxonil is a new fungicide being developed by Syngenta for the control of foliar and soil-borne diseases of ornamental horticulture crops.

Mandestrobin is a new systemic and translaminar fungicide being developed by Syngenta for the control of Botrytis and other foliar diseases of ornamental horticulture crops.

Pydiflumetofen + Azoxystrobin + Propiconazole was a new fungicide being developed by Syngenta for the control of leaf spots (Septoria, Cercospora,

Dimension was initially registered in 1992 for ornamental horticulture uses. This initial label contained an extensive list of ornamental horticulture plants in landscapes where Dimension

In 2013, as part of the crop safety screening for new active ingredients and recently registered fungicides, IR-4 started testing Mural WDG (benzovindiflupyr + azoxystrobin) for

Oxathiapiprolin was registered as Segovis in the United States in 2017 for disease control on ornamental horticulture plants in greenhouse and nurseries. The commercial label contains

Fluensulfone was registered as Nimitz Pro G in the United States in 2016 for nematode control in turf. Between 2012 and 2014, the IR-4 Project completed 13 trials on 8 ornamental horticulture

Metconazole was registered as Tourney 50WDG in the United States in 2007 as a turf fungicide. In 2010, uses for ornamental horticulture plants in greenhouse, nurseries, and landscapes were added.

Imazamox (Clearcast™) was registered for the control of vegetation in and around aquatic sites and terrestrial non-crop sites. in the United States in 2008. In 2009 and 2010, the IR-4 Project

Since 2007 IR-4 has completed 372 trials with products containing sulfentrazone + prodiamine (F6875 0.3G and F6875 4SC) on 92 crops. The data contained in this

  Flumioxazin has been registered in the United States since 2003 for uses in and around ornamental plants in production nurseries and in landscapes. Between 2000 and 2013, the IR-4 Project has

Tebuconazole was first registered in 1994 for peanut diseases. Since then its food use label has expanded to several other food crops. The first noncrop registration of Torque 3.6SC (tebuconazole)

From 2010 to 2013, IR-4 completed 28 trials on Bryophyter (Oregano oil). The data contained in this report was generated to register uses of active ingredient on and around ornamental

From 2012 to 2013, IR-4 completed 19 trials on Avenger Ag (d-limonene). The data contained in this report was generated to register uses of active ingredient on and around ornamental

From 2010 to 2013, IR-4 completed 14 trials on Scythe (Pelargonic acid). The data contained in this report was generated to register uses of active ingredient on and around ornamental

Since 2005 IR-4 has completed 192 trials with sulfosulfuron (Certainty 75WDG) on 79 plant genera or species. The data contained in this report was generated to register uses of sulfosulfuron on and

In an effort to provide weed management tools to growers of a wide variety of nursery ornamental crops this research was undertaken to expand the three pre-emergent herbicide labels:

Clethodim, a grass herbicide, was first registered in the US as Select Herbicide for ornamental horticulture crops in 1983 with a limited crop list. From 1997 through 2007, the IR-4 Project completed

From 2007 to 2011, IR-4 completed 144 trials on Mesotrione SC.  The data contained in this report was generated to register uses of mesotrione on and around ornamental horticulture plants

Data in this report were generated to expand registered uses of diuron on ornamental species. Diuron rates in these experiments ranged from 0.5 to 16 lb ai/A. Direx 80DF and Karmex 80WP were

Princep 80W, 90W, 4G, 4L and Caliber 90 DG were tested on 54 plant genera or species over a sixteen year period (1973- 1989). Data in this report were generated to expand registered uses of simazine

From 2006 to 2009, IR-4 conducted 293 trials with V-10142 0.5G and V-10142 75WDG (imazasulfuron) on more than 60 crops. This research was undertaken to determine the level of

Oxyfluorfen (Goal 2XL) has been registered in the United States since 1979 (Goal 2E) for uses in and around ornamental plants in production nurseries and in landscapes. The label recommends

Lontrel (clopyralid) was initially registered in 1998 for ornamental horticulture uses. This initial label contained an extensive list of ornamental horticulture plants where Lontrel could be used without causing

During 2008, IR-4 completed 97 trials on EXC3898 (mesotrione + prodiamine + s-metolachlor).  The data contained in this report was generated to register uses of EXC3898 on and around ornamental

Segment (sethoxydim), under the trade name Vantage, was initially registered in 1990 for ornamental horticulture uses. This initial label contained an extensive list of ornamental

Flumioxazin has been registered in the United States since 2003 for uses in and around ornamental plants in production nurseries and in landscapes. Between 2001 and 2006,

 Mogeton 25WP (quinoclamine) at 2, 4 and 8 oz product per gallon (1X, 2X and 4X rates) provides excellent control of liverworts in ornamental horticulture crops grown in containers in

Spirotetramat was registered as Kontos for use on ornamentals applied foliar or drench in the United States in 2008. The label recommends use on ornamental horticulture

Polyoxin D was registered as Endorse in the United States in 2003 as a turf fungicide. In 2005, this label was updated to include applications for certain diseases on ornamental crops.

Orvego, registered with EPA on May 21, 2012 is a combination of ametoctradin (FRAC 45) and dimethomorph (FRAC 40). In 2012, IR-4 started testing Orvego (ametoctradin +

From 2010 to 2013, IR-4 completed 38 trials on WeedPharm (acetic acid). The data contained in this report was generated to register uses of active ingredient on and around ornamental

From 2010 to 2013, IR-4 completed 24 trials on Racer (Ammonium nonanoate). The data contained in this report was generated to register uses of active ingredient on

Nematodes are typically known for the damage they cause when feeding on or residing inside roots. However, they also can impact foliage. The host range of foliar and soil dwelling nematodes is wide affecting various environmental horticulture crops,

From 2008 to 2022, 83 products were tested through the IR-4 Environmental Horticulture Program as foliar or drench applications against bacterial pathogens. In addition to research collected through the IR-4 program, this summary includes

Molluscs (slugs and snails) can cause significant feeding damage of environmental horticulture plants in production. Baits containg metaldehyde or iron phosphate are the primary means to manage molluscs. This project was initiated to examine the potential for active ingredients with less risky environmental

Fatty acid herbicides represent potential alternatives for managing glyphosate resistant weeds as well as an option for less environmental impacts for post emergent weed management. However, optimal use patterns have not been fully established. From 2020 to 2023, five different fatty

Root rots caused by Phytophthora species are often not noticed until foliar symptoms of wilting and stunting are observed. Phytophthora root rots are difficult to manage there are multiple species with differential sensitivities to fungicides.

Nutsedges and sedges (Cyperus sp.) are difficult to manage during the production of perennial environmental horticulture crops grown in containers or in the field. During the 2006 IR-4 Environmental Horticulture Workshop, a project was prioritized to screen for efficacious

From 1999 to 2023, 44 products or active ingredients were evaluated for Rhizoctonia solani management in greenhouse experiments as soil drench, soil incorporation, foliar or soak application, and in field experiments as soil drenches.

Liverworts (Marchantia sp.) are difficult to manage during the production of perennial environmental horticulture crops grown in containers. Liverworts are among the most serious weeds of container grown ornamentals.

Powdery mildew is a highly recognizable disease with pronounced colonies of white on foliage and, for some species, on petals. Due to the high number of spored produced, powdery mildews often develop resistance quickly to fungicides.

Managing scale insects presents unique challenges. Products with contact modes of action must be applied at specific timings in order to reach the most susceptible crawler stages. Products with

At the IR-4 Environmental Horticulture Program Workshop in 2011, Botrytis Efficacy was selected as a high priority project to expand the knowledge and list of fungicides available to growers for these diseases.

Managing mealybugs and scale insects presents unique challenges. Products with contact modes of action must be applied at specific timings in order to reach the most susceptible crawler stages

Collectively, managing coleopteran insects can be challenging because the adult and larval stages may both cause damage and sometimes occur on different hosts or on different plant parts.

At the IR-4 Environmental Horticulture Program Workshops in 2009 and 2019, Pythium Efficacy was selected as a high priority project to expand the knowledge and list of fungicides available to growers for these diseases.

For the last 16 years, the IR-4 Environmental Horticulture Workshop has ranked developing efficacy data on new products to manage thrips as a High Priority Project either nationally or regionally.

From 2001 to 2020, numerous products representing 40 active ingredients were evaluated in greenhouse and field trials as soil drench, soil incorporation, foliar,in-furrow, drip irrigation

From 2008 to 2020, 70 products were tested through the IR-4 Environmental Horticulture Program as drench or foliar applications against bacterial pathogens.

From 2003 to 2020, numerous products representing 35 active ingredients were evaluated in greenhouse experiments as soil drenches against Thielaviopsis basicola causing black root rot

At the IR-4 Environmental Horticulture Program Workshop in 2011, Botrytis Efficacy was selected as a high priority project to expand the knowledge and list of fungicides available to growers for these diseases.

Nursery growers have had a longstanding battle to control weeds in environmental horticulture crops. Bittercress(Cardimine spp.), is one of the most difficult weeds to control

Nursery growers have had a longstanding battle to control weeds in environmental horticulture crops. Spurge (Chamaesyce maculata), is one of the most difficult weeds to control

From 2004 to 2012, fenamidone (FenStop, FenStar) was screened through the IR-4 Program as drench or foliar applications for effacay against nine Phytophthora species causing root rots and

Nursery growers have had a longstanding battle to control weeds in environmental horticulture crops. Oxalis (Oxalis spp.) is one of the most difficult weeds to control in

Over a 5-year timeframe starting in 2013, the team of researchers listed above investigated several downy mildews – Impatiens and Cucurbit, primarily,

From 1999 to 2016, 34 active ingredients were tested mainly as foliar applications against several genera and species of mite pests on ornamentals and vegetables.

At the IR-4 Environmental Horticulture Program Workshop in 2015, Algal Leaf Spot Efficacy was selected as a regional special project for the Southern Region

From 2009 to 2015, numerous products representing 15 active ingredients were evaluated in the greenhouse to control dipteran leafminers (Liriomyza trifolii and other species). Nine

In 2008, IR-4 initiated a high priority project to determine efficacy of several fungicides on downy mildew pathogens so data can be obtained to support current and future registrations.

In this review of literature published from 1999 to 2016, 99 products representing 57 active ingredients were screened in greenhouse and field experiments against several species

At the IR-4 Ornamental Horticulture Program Workshop in 2013, leaf spots and anthracnose efficacy was selected as a high priority project to expand the knowledge

Whiteflies are significant pests of ornamental horticulture crops. Three whiteflies species and biotypes contribute to crop production losses in the United States: greenhouse whitefly

From 2000 to 2011, numerous products representing 30 active ingredients were tested as foliar applications against several genera and species of pathogens causing rust on

Hydrangeas are an increasingly popular group of shrubs which are prized for their flowers. Ornamental growers produce numerous varieties for the landscape, as well as, holiday florist markets.

Three plant growth regulators, Augeo (dikegulac sodium), Configure (6-benzladenine) and Florel (ethephon), were tested to determine their potential for improving branching and quality

The project entitled “Determining the impact of registered and non-registered fungicides and disinfestants on Uromyces transversalis, the causal agent of

Potted plants like geranium and impatiens are typically grown in the warmer regions of the United States and require shipping to reach northern markets for sale to

From 2008 through 2011, fourteen pre-emergent herbicides were tested across the United States through the IR-4 Ornamental Horticulture Program to determine whether they can control

Data in this report were generated to evaluate several products for post-emergent control of liverworts (Marchantia sp.). Liverworts are among the most serious weeds of container grown ornamentals.

Pyrifluquinazon is a new active ingredient for the management of sucking pests, such as aphids, thrips, whiteflies and more. Its mode of action is to halt insect feeding so that they starve.

Hachi-Hachi 15EC (tolfenpyrad) was registered July 28, 2010 for the control of aphids, leafhoppers, scales, thrips, whiteflies, and early instar lepidopteran larvae on ornamental

From 2000 to 2007, IR-4 researched crop safety and efficacy of Medallion (fludioxonil), Vanguard (cyprodinil), and Palladium (Switch 65WG, cyprodinil + fludioxonil).

The project entitled “Developing sustainable methods for controlling invasive pests on ornamental plant cuttings” had 6 objectives with two primary goals of

In the past, IR-4 had conducted Ornamental Horticulture Surveys to poll growers, landscape care operators, researchers, extension personnel and others