IR-4 summary of ornamentals research

The IR-4 Project has released its list of ornamental summary reports, and the package is packed with information regarding the toxicity and/or relative safety of the products you use to produce your best crops.

Among the most recent studies available are Acibenzolar crop safety (2013); a bacterial disease efficacy summary (2012); cyflufenamid crop safety report (2013); Dimethenamid-p + Pendimethalin crop safety summary (2013); Dimethenamid-p crop safety report (2013); Isoxaben crop safety report (2013); Olyfluorfen + Prodiamine crop safety study (2013) and Scale and mealybug efficacy report (2013), among others.

If you’re not familiar with the IR-4 Project, get familiar. The IR-4 Ornamental Horticulture program began in 1977 to study the disease, insect and weed management tool and plant growth regulator needs of growers. Originally focused primarily on greenhouse- and nursery-grown plants, the program now encompasses landscape plantings as well as Christmas tree farms and others.

The purpose, basically, is to generate crop safety information and efficacy data for high-priority projects for disease and pest problems – those that are identified by folks just like you.

For more information, visit

Photo courtesy of Dawn Dailey O’Brien, Cornell University;

Rose rosette confirmed in Florida

Three counties in Florida have confirmed the presence of rose rosette virus (RRV), the cause of rose rosette disease, a disfiguring and ultimately lethal affliction. The disease and the presence of the virus were detected in Florida in November 2013, and subsequently confirmed by the lab at Florida’s Division of Plant Industry-FDACS, Gainesville, in January.

The scourge of Rosa multiflora, rose rosette disease has spread to cultivated plants, and authorities in Florida have confirmed that all the infected plants in Florida belong to the Knock Out® series.

First observed on wild roses in Canada in 1940, the disease has since made inroads into the U.S. Symptoms include the development of witches’ brooms, curled and deformed foliage, unusual red coloration of foliage (that does not change with age), distorted buds and severe proliferation of thorns. Infected plants usually die within a year or two.

At present there is no cure for rose rosette disease, and all infected plants must be destroyed to prevent spread.

Mountain pine beetle larvae
Photo courtesy of USDA Forest Service – Region 2; – Rocky Mountain Region Archive;

For more information on the disease, visit

The Big Chill for insect pests

This winter’s record cold snaps – Polar Vortex, anyone? – might have been tough on heating bills, but the frigid temps could also spell disaster for forest insect pests. At least some of them.

Hemlock woolly adelgid infestation
Photo courtesy of John A. Weidhass, Virginia Polytechnic Institute and State University;

According to Robert Venette, a U.S. Forest Service research biologist in Minnesota, up to 80 percent of emerald ash borers may have been killed off in areas where temperatures reached 22 to 26 below zero. (That’s air temperature, not wind chill, which would not affect pests smart enough to burrow under the protective cover of tree bark.) Venette says that gypsy moths also are subject to die off, as they are susceptible when the mercury reaches 17 below. Gypsy moth populations have moved into the northern part of the state and consume more than 300 species of trees and shrubs, Venette says. Several parts of the state reached air temperature lows of minus 30 to minus 38 early in January.

In Colorado, where mountain pine beetle has devastated thousands of acres of ponderosa and lodgepole pines, this winter’s frigid spells may not have lasted long enough to kill off the pest. Colorado State University Extension experts state that midwinter temps must sustain at 30 below for at least five days in order to affect the larvae of this voracious beetle.

Similarly, the cold may not have been prolonged enough to threaten woolly adelgid in the eastern U.S., where the pest has destroyed hemlock stands from New England to North Carolina and beyond.