There's a new herbicide specifically aimed at ornamental plant growers. Called Marengo (OHP, Inc.), the new received its federal EPA registration and is undergoing the state registration process. With the new active ingredient indaziflam, Marengo is a selective pre-emergent herbicide that promises long-term residual control of both grassy and broadleaf leaves.
Marengo is registered for use on production ornamentals grown in outdoor nurseries, as well as on conifers, Christmas trees, and ornamental production sites and hardscapes. Marengo is labeled for use in shade houses and hoop houses as well. It uses rates range from 7.5 to 18.5 fluid ounces per acre depending on soil type and conditions. It performs best when applied to bare ground or mixed with a post-emergent herbicide to eliminate existing weeds. Ohp.com/Products/marengo.php.
The Michigan departments of Natural Resources and Agriculture and Rural Development are warning landscape contractors, property owners and roadside mowing crews to be on the lookout for Japanese knotweed, which was originally prized as an ornamental plant.
Knotweed Invading Michigan
The aggressive intruder is now feared for its ability to crowd out native plants and spread easily, such as along streambeds. One of nine invasive plant species with a special profile on the DNR's website, Japanese knotweed is getting special attention as a prohibited plant, meaning it's illegal to possess in the state. Sue Tangora, the invasive species coordinator for the DNR, said Japanese knotweed, which is probably in every county in Michigan. It also has been reported on Belle Isle.
"Maximally evil," is how Leslie Kuhn, coordinator of the Mid-Michigan Stewardship Initiative, describes Japanese knotweed, a plant also known as false bamboo because of the appearance of its hollow stems.
Japanese knotweed is difficult to control, and officials say use of special targeted herbicides "?u Kuhn recommended imazamox "?u appear to be the only effective method. Eradicating the plant can take years of chemical reapplications.
LebanonTurf recently introduced products for landscape markets that offer advanced protection against weeds and pests, along with the feeding properties of MESA, the company's patented nitrogen source.
New products to weeds and pest-fighting products from LebanonTurf
ProScape 19-0-6 30-percent MESA with LockUp plus Dimension is the company's exclusive combination product of pre- and post-emergent weed control, which is said to match the strength of Dimension with the of LockUp to extend the application period.
The latest addition to the ProScape line is the only product in the market with both penoxsulam, a broad spectrum herbicide for turf; and Dimension, a herbicide used in the early control of crabgrass and other annual grasses and broadleaf weeds.
Each of the products is fortified with MESA, LebanonTurf's patented nitrogen source that combines ammonium sulfate with methylene urea in a single particle. The result is an effective and efficiently controlled delivery of nitrogen that produces consistent, brilliant color without excessive growth. Unlike coated fertilizers, MESA does not lose its slow-release properties when cracked, chipped, crushed or broken.
Described as as "extremely damaging" to plants and capable of causing "cataclysmic effects in the landscape," the White Fly has been reported in the Tampa Bay, Florida area.
White Flies Invading Florida
Mayor John Robertson said recently that some residents had reported swarms of whiteflies attacking their palm trees.
According to a bulletin issued by the Pinellas County Extension Service in July headlined "Whitefly Invasion," the pests "can reach very high populations and can be extremely damaging." The flies feed on a broad range of plants, including palms, woody ornamentals and fruits.
Their presence is easy to spot. The white, waxy, web-like substance they leave on the plant is unmistakable. Also evident is the "honeydew," a sticky substance they produce which causes the growth of a mold that looks like black soot..
The whiteflies were first seen in Miami-Dade County in 2009 and have since migrated to the west coast of Florida, reaching Pinellas County in recent months.
Controlling Whiteflies
Pest control must be done with care to avoid destroying the whiteflies' natural enemies, called parasitoids, which eat their larvae. Insecticides often kill both the good and the bad insects, especially when sprayed said County Extension Service Agent Jane Morse.
"The [whiteflies'] natural enemies do the bulk of pest control, and you don't want to kill them," Morse warned.
She recommends treating small whitefly infiltrations first by washing the plants off with water. This can be done with a hose to reach tall trees.
Use of a horticultural oil to spray on foliage, and insecticidal soap also can be helpful in controlling whiteflies. These are available at nurseries and garden centers. The soaps and oils "do work really well," Morse said. A hose or sprayer can be used to apply them. She recommends a drench, starting at the base of the tree.
While large or persistent whitefly infestations may require the use of insecticides, their misuse or overuse may cause other problems such as insecticide resistance, secondary pest problems, environmental contamination, and destruction of beneficial insects, Morse said.
