February 15, 2008
Highlights of new turf research
By Pam Charbonneau
OMAFRA turf specialist
A Happy New Year to all. I hope everyone has had a chance to re-charge their batteries after the busy 2007 growing season.
The early January thaw gave us a chance to observe some of the problems that are occurring on turf. Grub damage is already a noticeable problem. I think that there will be more where that came from in the spring. Turf was very poorly rooted because of the dry conditions all summer and the roots that were there were easily pruned by the grub feeding. The result has been widespread turf loss.
I had the opportunity to attend the Crop Science Society of America meetings in New Orleans in the fall. There are four full days of turf scientific talks at this meeting. I want to share with you a couple highlights of the meeting that may be of interest to people in the lawn care industry.
Pam Charbonneau can be reached at (519) 824-4120, ext. 52597 or by e-mail at pamela.charbonnea@ontario.ca.
OMAFRA turf specialist
A Happy New Year to all. I hope everyone has had a chance to re-charge their batteries after the busy 2007 growing season.The early January thaw gave us a chance to observe some of the problems that are occurring on turf. Grub damage is already a noticeable problem. I think that there will be more where that came from in the spring. Turf was very poorly rooted because of the dry conditions all summer and the roots that were there were easily pruned by the grub feeding. The result has been widespread turf loss.
I had the opportunity to attend the Crop Science Society of America meetings in New Orleans in the fall. There are four full days of turf scientific talks at this meeting. I want to share with you a couple highlights of the meeting that may be of interest to people in the lawn care industry.
Mulched maple leaves for dandelion control
Dr. Ron Calhoun and Dr. Trey Rogers of Michigan State University gave a presentation. Research conducted from 2003 to 2005 at Michigan State University showed that leaves collected from a variety of species, particularly sugar maple species, mulched into established turfgrass, resulted in increased spring green-up and fewer dandelions than control plots. They ground up the tree leaves and also left them intact. There was no significant difference in spring green-up or dandelion control, attributable to size of the leaf particles. The highest rate of leaf mulch (1.5kg/m2) gave the best green-up and the best dandelion control. The maple species and red oak gave the best dandelion control. It appears that, like corn gluten meal, this approach could act as a natural weed and feed treatment for home lawns. This could be a partial solution for weed control in municipalities that have enacted a pesticide bylaw. The authors will attempt to determine the exact mechanism or component in the leaves that has the herbicidal properties and also see if the activity is pre or post-emergence.How long can dormant cool season grasses go without rainfall?
I found research by Dr. Paul Johnson, Utah State University, especially relevant after the 2007 season. Extended droughts in the western United States have resulted in water restrictions being put on landscape irrigation. In severe cases, watering has been banned completely due to shortages. In the event of such water restrictions, turfgrasses often enter summer dormancy and can survive for significant periods of time without water. However, the extremely dry and very warm conditions in the west often exceed the drought tolerance of the grasses, even when dormant. By four weeks of drought, species recovery differences started to show. By eight weeks of drought recovery, differences were pronounced and by two-and-a-half months, all species suffered. Perennial ryegrasses lose significant stands after several weeks. If able to root deeply, tall fescue tolerated extended drought well (two-and-a-half months without water). The authors also found that watering with 2.5 cm of water a month kept most cool season species of turf alive without bringing them out of dormancy.Evaluation of Texas hybrids and tall fescue for drought tolerance
A two year field study at Auburn University by Dr. Jacob Dane, Auburn University, included the hybrid bluegrasses [Texas bluegrass x Kentucky bluegrass], HB 129 (Thermal Blue), HB 130, HB 328 and HB 329 (Dura Blue) and the tall fescue, Green Keeper and Kentucky 31 cultivars. These new hybrids have the quality of Kentucky bluegrass and the drought tolerance of Texas bluegrass. These hybrids were irrigated at a rate of 100, 80 and 60 per cent of potential evapotranspiration. Turf quality values were determined using digital images, while root-length density and root dry mass values were determined from samples collected in July and September of 2005 and 2006. Results show that irrigation treatments did not significantly affect any of the response variables. The hybrid bluegrasses showed higher root-length density and turf quality values, compared to the tall fescue cultivars. Rankings based on root-length density and turf quality were: HB 329 (Dura Blue) [best performance] > HB 130 > HB 328 > HB 129 (Thermal Blue) > Kentucky 31 tall fescue > Green Keeper tall fescue [least performance]. This research suggests that irrigating at 60 per cent potential ET with the Texas x Kentucky bluegrass hybrids will still yield turf with high quality and save water. These hybrids could provide a viable alternative to Kentucky bluegrass for Ontario. They have been shown to require less water and they do not go dormant the way Kentucky bluegrass does in a dry year with water restrictions.Pam Charbonneau can be reached at (519) 824-4120, ext. 52597 or by e-mail at pamela.charbonnea@ontario.ca.