Seminar covers chemical runoff, grub control

WOOSTER, Ohio – The Ohio Lawn Care Association’s Eighth Annual Northeast Ohio Lawn Care Seminar brought about 120 professionals together yesterday to network, catch up on the latest scientific research and earn continuing education credit. The OLCA held the seminar at the Ohio State University’s Ohio Agricultural Research and Development Center in Wooster, Ohio.

Nutrient runoff in urban lawns
Zhiqiang Cheng, a researcher at OSU, opened the program with a general session where he explained expeAndy Walters explains the importance of equipment speed during calibration. Photo courtesy of Denise Brosie.riments he held to measure runoff difference between subsoil and topsoil. He created plots on four-degree slopes and applied fertilizer. After letting the fertilizer sit for  48 hours, he then applied one hour of rainfall at 3.5 inches per hour.

Cheng found that the runoff initiation time was significantly shorter for subsoil lawns than for topsoil lawns. The total runoff volume was also significantly higher for subsoil. The subsoil experienced greater losses in sediment and nutrients.

Turfgrass insect identification and management
Kevin Power, research associate for the OARDC, reminded attendees to “think of your grass as an ecosystem.” He explained that landscapers should identify the particular type of grub they’re dealing with in order to better formulate a pest management strategy.

Power passed out sheets with pictures of nine grub species each with a unique raster pattern, which is the arrangement of bristles and hairs on the underside of the tip of the abdomen. He stressed that proper identification requires straightening the grub from its normal, C-shaped posture and using a 10x hand lens to get a clear view.

He says microclimates on a property, such as areas below a south-facing glass wall or areas with underground steam pipes, can alter the grub population as well.

Biphasic rain gardens
Hanbae Yang, research associate for the OARDC, explained how landscapers can install gardens designed to hold and filter runoff from impervious surfaces. The rain garden concept is gaining popularity, he says, because they are effective in removing sediment and heavy metals.

Yang explained five steps for building a rain garden:

1: Choose a low-lying site. Consider distance and direction of water flow.
2: Determine the size and depth of the rain garden.
3: Dig garden and place in bedding material. Yang says rain gardens work with a bedding medium generally composed of mixture containing about 60 percent sand, 20 percent compost and 20 percent soil.
4: Select plant material. He suggests using native, non-invasive plants.
5: Water the plants regularly for the first year until they’re established.

He says the rain garden should have a high infiltration rate in order to hold as much runoff as possible. The highest cost for such a project, he says, is the soil medium.

Equipment calibration
Some landscapers might blame pressure problems when they spray a field and run out of material too soon. Andy Walters, sales representative for L.T. Rich Products, says the three things that effect the amount of spray used are equipment speed, pressure and the size of the spray tip, but equipment speed is the greatest factor.

Walters says the most affordable way to calibrate your equipment is to purchase a GPS device that will tell you exactly how fast you’re going. Customers could also opt to buy the Z-Spray Z-Max, which has an adjustable speed bar to control ground speed.

Solving lawn problems
After the group sessions, the audience reconvened in the auditorium to hear OSU Plant Pathologist Joe Rimelspach explain turf disorders. Rimelspach says disorders can be divided into biotic and abiotic factors.

Biotic disorders are problems caused by living things. These include infectuous diseases from fungi, bacteria and viruses; non-infectious living things such as algae and moss; insects and animals; and humans.

“People are a huge factor,” he says. “We cause more problems on turf than anything else.”

Abiotic disorders are caused from non-living things. The environment can have several roles in causing abiotic disorders, including temperature extremes, poor quality soils, soil compaction and root competition. Physical causes include mowing, turf use and frost. Chemical factors, such as pesticides, animal urine, soil salinity, nutrient extremes and chemical spills, can also hurt turfgrass.

Rimelspach created a nine-step approach to solving lawn problems:

1: Have a working knowledge of plant sciences.
2: Understand the “big picture” or overall condition of turfgrass in the area.
3: Indentify the species of the grass.
4: Observe signs and symptoms on the plant.
5: Observe the site’s lighting, soil characteristics and drainage.
6: Gather environment conditions and information about weather patterns at that location.
7: Investigate maintenance practices and history of the problem.
8: Identify any microscopic pathogens. If no pathogen is found, then the cause is not a disease.
9: Use information and observations to make conclusions.

To help with pathogen identification, OCLA members can send three samples to the OSU lab free of change. Charges for non-members are $75 for Ohio residents and $150 for out-of-state residents. A guide for sending samples can be found on OSU’s website.