Weather forecasters have a 50/50 chance of accurately reporting daily and weekly weather. Unfortunately, lawn and landscape professionals don’t have that same luxury when forecasting weed and insect outbreaks in lawns and landscape beds.
No matter the region, weather typically wreaks havoc with at least one of a contractor’s programs or service plans.
2008 was a “perfect storm type of year” with more evidence of soil root-borne disease such as summer patch and necrotic ring spot than in the past five to six years; particularly in New England, says Mike Agnew, technical manager for Syngenta Professional Products. On the contrary, dollar spot and anthracnose haven’t presented such difficulties this season.
Disease problems reared their ugly heads mainly on southerly and west-facing banks that are subjected to intense heat. Heavy spring rainfalls in the Northeast were to blame, resulting in saturated soils and reduced soil oxygen levels followed by the heat stress of summer.
Also, excessive rains were to blame for weed breakthrough in some regions. While weeds haven’t been pervasive this year (unlike crabgrass break-through in 2007), heavy rains contributed to preemergent herbicide breakdown. Increased degradation was evident on slight rather than thicker lawns, and on seeded vs. sodded turf, Agnew says.
Sod webworms were responsible for damage on home lawns; however, preventive treatments generally suppressed them.
While the mid-Atlantic region didn’t experience the flight of the adult Japanese beetle this year, Midwest contractors battled an above-average grub population. Conditions were right – not too wet and not too dry – for grubs to thrive. Additionally, plenty of ground moisture may have been responsible for moving preventive applications of insecticides lower in the soil profile.
Dave Shetlar, Ph.D, department of entomology, The Ohio State University, says significant grub damage has been showing up in turf – even turf that was treated with a grub control insecticide in May and June. He is quick to point out that he hasn’t seen massive product failures; rather localized spots where grubs are in sufficient numbers to damage the turf.
Microbial degradation and thick thatch layers are common culprits, as are general quantities of grubs. “We are seeing areas that the grub egg laying was intense and populations are appearing in the 50 to 60 grubs per square foot and they are munching away,” Shetlar says. “Even if a grub insecticide kills 90 percent of these grubs, there will still be five to six grubs per square foot remaining.”
Additionally, the thatch layer drops the efficacy of the insecticide down to the 70 percent level and the property ends up with 15 to 18 grubs per square foot, still considered a damaging population. So, in some cases, the grub insecticide did pretty well, but the grub pressure was so high that damage may still result. In these cases, another application may be needed to knock down the survivors.
West of Colorado experienced a very different pest scenario this year with a cooler than normal spring and summer resulting in fewer issues with hot weather diseases, says Dean Mosdell, technical manager for Syngenta.
In fact, it’s been a fairly good year for growing turf in the West with below average temperatures based on 30-year averages, and later incidence of crabgrass if any.
Billbugs were the story in Idaho and Utah while clover made its appearance in mid-Atlantic and NE regions mid-summer, too late for spring broadleaf herbicide applications.
No matter the region, weather typically wreaks havoc with at least one of a contractor’s programs or service plans.
2008 was a “perfect storm type of year” with more evidence of soil root-borne disease such as summer patch and necrotic ring spot than in the past five to six years; particularly in New England, says Mike Agnew, technical manager for Syngenta Professional Products. On the contrary, dollar spot and anthracnose haven’t presented such difficulties this season.
Disease problems reared their ugly heads mainly on southerly and west-facing banks that are subjected to intense heat. Heavy spring rainfalls in the Northeast were to blame, resulting in saturated soils and reduced soil oxygen levels followed by the heat stress of summer.
Also, excessive rains were to blame for weed breakthrough in some regions. While weeds haven’t been pervasive this year (unlike crabgrass break-through in 2007), heavy rains contributed to preemergent herbicide breakdown. Increased degradation was evident on slight rather than thicker lawns, and on seeded vs. sodded turf, Agnew says.
Sod webworms were responsible for damage on home lawns; however, preventive treatments generally suppressed them.
While the mid-Atlantic region didn’t experience the flight of the adult Japanese beetle this year, Midwest contractors battled an above-average grub population. Conditions were right – not too wet and not too dry – for grubs to thrive. Additionally, plenty of ground moisture may have been responsible for moving preventive applications of insecticides lower in the soil profile.
Dave Shetlar, Ph.D, department of entomology, The Ohio State University, says significant grub damage has been showing up in turf – even turf that was treated with a grub control insecticide in May and June. He is quick to point out that he hasn’t seen massive product failures; rather localized spots where grubs are in sufficient numbers to damage the turf.
Microbial degradation and thick thatch layers are common culprits, as are general quantities of grubs. “We are seeing areas that the grub egg laying was intense and populations are appearing in the 50 to 60 grubs per square foot and they are munching away,” Shetlar says. “Even if a grub insecticide kills 90 percent of these grubs, there will still be five to six grubs per square foot remaining.”
Additionally, the thatch layer drops the efficacy of the insecticide down to the 70 percent level and the property ends up with 15 to 18 grubs per square foot, still considered a damaging population. So, in some cases, the grub insecticide did pretty well, but the grub pressure was so high that damage may still result. In these cases, another application may be needed to knock down the survivors.
West of Colorado experienced a very different pest scenario this year with a cooler than normal spring and summer resulting in fewer issues with hot weather diseases, says Dean Mosdell, technical manager for Syngenta.
In fact, it’s been a fairly good year for growing turf in the West with below average temperatures based on 30-year averages, and later incidence of crabgrass if any.
Billbugs were the story in Idaho and Utah while clover made its appearance in mid-Atlantic and NE regions mid-summer, too late for spring broadleaf herbicide applications.
Explore the October 2008 Issue
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