The best kept secret in botrytis control

February 11, 2021

Let Astun® Ornamental Fungicide give relief to at least one cold weather headache. An application of Astun willAstun Ornamental Fungicide by OHP, Inc. provide rapid control of botrytis spp. on spring crops, including plants in full bloom, with no phytotoxicity potential.

Astun provides preventative, systemic, and curative activity on ornamentals grown in commercial greenhouses and nurseries, including plants in color.

Users should add a spreader sticker of their choice with Astun to reduce the possibility of residue on leaves and flowers. Astun provides fast and outstanding botrytis control with the active ingredient isofetamid, a new fourth-generation member of the SDHI class of chemistry, mode of action (MOA) group 7.

Use rates range from 10-17 fl. oz. per 100 gal. of water.

Astun carries a 12-hour REI and Caution signal word.

OHP also offers a Botrytis Recipe for Success which contains great rotational information for growers.


Paul Pilon joins OHP technical staff

December 7, 2020

OHP, Inc. is proud to announce the addition of industry veteran Paul Pilon as Technical Manager, effective immediately.

Paul Pilon with OHP, Inc.Paul Pilon, Technical Manager with OHP, Inc. “We are pleased to add Paul to our team of dedicated professionals,” says Dan Stahl, OHP vice president and general manager.” He’s a former grower and he brings growing experience, crop expertise, product knowledge, diagnostic ability, research capabilities, communication skills, and other strengths to OHP.”

Paul is well-known and respected in the horticulture industry, having founded and operated Perennial Solutions Consulting since 2005. His client list included key growers from every region of the U.S. and internationally.

He has written numerous articles for industry trade magazines and has produced Perennial Pulse e-newsletter for Ball Publishing since 2014.

In addition, he has written a bi-monthly column “Paul Talks Perennials” for Grower Talks magazine since 2017. He authored a book on perennial production in 2006.

“As hard as the decision to leave my successful consulting business behind may seem, the choice was somewhat easier than I thought,” he says. “Being an industry leader, OHP has the resources to pursue research and projects I could never attempt on my own and they are committed to developing products growers need.”

With his background in plant growth regulators and herbicides, Paul teams with OHP Senior Technical Manager Dr. Carlos Bográn, who specializes in insecticides and fungicides, to comprise the OHP technical staff.

A frequent speaker at industry events including Cultivate and Far West, Paul began his career as a grower at Neal Mast and Son Greenhouses in Grand Rapids, MI and later served as head grower at Sawyer Nursery in Hudsonville, MI. He holds a bachelor’s degree in horticulture from Michigan State University.

He and his family currently reside in Jenison, MI. Please welcome him to the OHP family.


Let OHP help build your herbicide rotation plan.

September 23, 2020

OHP's Herbicide Rotation Program 2020

A quality pre-emergent herbicide works to prevent weeds from germinating. Choosing the correct product(s) and using them properly is not so simple. Herbicide performance is a matter of application rate, environmental conditions, watering practices, and frequency of use.

Overuse of a particular herbicide may set the stage for herbicide resistance. Herbicide rotation is critical in getting the most out of a weed control program.

It is important to rotate MOA (Mode of Action) with herbicides just as with insecticides. Rotating MOAs will help prevent the creation of dominant weed species based on its tolerance to particular MOAs.

OHP has developed a wide range of granular herbicides designed to meet different grower needs, seasons, and crops. OHP herbicides are formulated on a uniform and dustless granule. These unique premium formulations increase delivery accuracy, and provide cleaner conditions for applicators and excellent plant tolerance.


Biathlon Herbicide from OHP, Inc.Fortress Herbicide from OHP, Inc.Fuerte Herbicide from OHP, Inc.

For more information on herbicide rotation, weed identification and control, contact your Regional Technical Sales Manager.


OHP adds Grotto Fungicide to biosolutions portfolio

April 20, 2020

OHP, Inc., announces the addition of Grotto™ Fungicide/Bactericide to its leading stable of pest control solutions for theGrotto Organic Fungicide/Bactericide ornamental industry.

Available immediately, Grotto is a high-quality copper octanoate, broad-spectrum fungicide that has activity on many greenhouse and nursery fungal and bacterial diseases.

Labeled for use on ornamentals plus vegetables and herbs grown in greenhouses, shadehouses, and nurseries. Grotto has a 4-hour Restricted Entry Interval (REI), Caution signal word, and OMRI (Organic Materials Review Institute) listing.

Grotto fits well in our biosolutions® segment and fulfills a grower’s need for shorter REI products and broadly-labeled products,” says Dan Stahl, OHP vice president and general manager. “Growers are demanding more products with 4-hour REIs.

Grotto is labelled for control of several challenging fungal and bacterial diseases such as bacterial leaf spot and blight, botrytis, downy mildew, fire blight, fungal leaf spot, powdery mildew, and rhizoctonia, on many ornamentals.

With Grotto and Kalmor® Fungicide/Bactericide in our biosolutions product portfolio, we now offer a broad range of copper-based solutions for our grower customers,” says Stahl.

OHP is a leading supplier of pest control solutions to the greenhouse and nursery markets.


How do I slow plant growth?

March 27, 2020

Growers have asked, “What can be done to slow growth on crops during times of low demand? “ —A great question. Let’s look at the available options.


If you find your crops growing under lower light levels, warm temperatures and heavy fertilization, excessive growth or stretching can occur. Excess growth can be slowed by growing crops cooler with increased spacing and using less water, a term called growing “harder.” If space allows, increase plant spacing and if crops can take colder temperatures in the 60º F range, you may want to consider this approach. The use of negative DIF (difference between daytime and nite time temp.) is also a growing technique useful during finish and can help reduce plant height.

OHP Plant Growth Regulators (PGRs)

Chemical plant growth control is a standard tool for growing many crops and is used during early plug, liner, and early to mid-finish production. Late application of PGRs to plants can offer growth control for a short period of time or stop growth in order to hold a crop for a long time. Such applications are done with a drench of triazole-based PGRs such as OHP’s Pac O. Below are suggested OHP products and rates that can offer late growth control.

B-Nine® WDG

A spray application at 2500 to 3750 PPM (mums) or 5000 PPM can offer growth control on a number of plants. Zinnia, coleus, mums and other large leafed plants respond well from B-Nine WDG foliar applications. Apply early in the morning and do not overhead water for 24 hrs. The lower rate of 2500 PPM is less risky but users may need to make a couple of applications. A tank-mix of B-Nine WDG at 1250 or 2500 PPM plus Cycocel at 1000 PPM will increase effectiveness. DO NOT use Cycocel rates over 1200 PPM.


We do not recommend the use of Cycocel in late finish as the rates needed for growth control may produce a yellowing. Cycocel is best used early to mid-cycle in crop production.

Pac O™ (Spray applications)

Foliar applications can vary wildly depending on the crops involved. Remember that viola, geranium, and begonia are VERY sensitive to Pac O. Sprays could range from 2 to 5 PPM. For other herbaceous crops use the mid to higher rate recommendations making sure to cover stems as best as possible; consider rates of 15 to 30 PPM. If crops have more leaves than stems showing you should consider B-Nine WDG sprays.

Pac O™ (Drench applications)

Drench applications are very effective in holding crops over. Consider using from 1 to 4 PPM using the correct drench volume for the pot size. A 1 PPM drench is like a 10 PPM spray. This 10:1 ratio can help you to determine what drench rate to use. Petunia baskets that are up to size will hold well using a 4 PPM drench.

Woody ornamentals are probably best held in check by using high spray rates or moderate drench rates of Pac O. Plants like azalea and other woody plants would use 100 to 150 PPM as a spray or 10 to 15 PPM as a drench. Lantana or other smaller plants respond well to a 2 PPM drench.

Generally speaking, one drench application should hold for 4 weeks or possibly longer. Drench volume is very important and users should follow the container drench volume rates in the label.