April 7, 2008
Seashore Paspalum Traffic Tolerance Study Underway
To date, 36 simulated traffic passes have been applied to experimental
plots at Punchbowl National Cemetery. These treatments were initiated
on March 18th, 2008 and will continue to until May 13th. Percent
turfgrass cover is rated weekly. Tifway 419 and Seadwarf are yielding the
highest percent turfgrass cover ratings, while Sea Isle 2000 is yielding
the lowest. The results of this project will be discussed in detail at
the 2008 Landscape Industry Council of Hawaii (LICH) Conference and Trade
Show, May 28-29th. Click here
Want to see the CADY Traffic Simulator in action? Click
Univ. of Hawaii Turfgrass Survey Complete
Thank you to all those individuals that completed the 2007 University
of Hawaii Turfgrass Industry Survey. The deadline to submit responses has
passed, and we will now begin to analyze the data collected. Participation
from the golf course industry was strong, with over 56 individuals identifying “Golf
Course” as the type of property that they maintain (Figure 3). Look
for a full presentation of the results at the 2008 Landscape Industry Council
of Hawaii (LICH) Conference and Trade Show, May 28-29th. Click
control of seashore paspalum with Basamid
A study evaluating options for non selective control of seashore paspalum
is entering its final weeks at Windward Community College on Oahu. Applications
of a granular soil fumigant, dazomet (marketed as Basamid®), seems
to be providing nearly nearly 100% control 5 weeks after treatment (Figure
4); however, percent control ratings will continue for another three weeks.
Seashore paspalum control following applications of glyphosate (marketed
as Roundup Pro), fluazifop (marketed as Fusilade II), and glyphosate +
fluazifop at the highest label rates have not provided the same level of
efficacy as Basamid (plots not shown). A full report will be posted on
this site when the project is complete. Before making a final conclusion,
the study will be replicated again this summer.
March 1, 2008
Seashore Paspalum Traffic Tolerance Study
Research plots at the National Memorial Cemetery of the Pacific (Honolulu, HI) are currently being prepared for a study investigating the effects of vertical mowing and nitrogen fertilization on the traffic tolerance of various seashore paspalum cultivars. The entire experimental area was verticut this week and topdressed with silica sand. The effects of two fertility and vertical mowing regimes on traffic tolerance will be evaluated. Simulated traffic will be applied with a CADY traffic simulator (Figure 1) beginning in late March. Two passes with this instrument simulates a level of traffic equal to one NCAA football game. 18 simulated games will be applied per week, with surface hardness, soil moisture content, turfgrass color, density, and chlorophyll content measured after 0 and 90 games. Percent turfgrass cover will be measured weekly for the duration of the study.
Want to see the CADY Traffic Simulator in action? Click here (.AVI file)
Seashore Paspalum Weed Control Updates
A second round of research trials investigating hilograss (Paspalum conjagtum) control in seashore paspalum was initiated in late Januray at Ko’olau Golf Course (Kaneohe, HI). Similar to what was observed in research conducted in October 2007 at the same facility, two applications of sodium chloride (83% 0.25-0.50mm in diameter) at a rate of 10 lbs per 1000 ft2 (on a 7-day interval) provided nearly 100 percent control of hilograss with minimal damage to the surrounding ‘Salam’ seashore paspalum (Figure2). Soil data collected as part of our October 2007 testing revealed that this management strategy had no affect on soil SAR values. Research is still on-going, but results look quite promising.
Selective Seashore Paspalum Control in Hybrid Bermudagrass?
Options for selective control of seashore paspalum in hybrid bermudagrass are extremely limited. However, in a recent study evaluating seashore paspalum renovation techniques, a new potential option may have been discovered. Two applications of Confront + MSMA (2 pt/Acre + 2 lbs A.I. /Acre), on a 7-day interval, provided nearly 100% control of seashore paspalum five weeks after initial treatment (Figure 3). Percent control will be monitored until April 2008 to determine if re-growth occurs. Given that both Confront and MSMA are both labeled for use on hybrid bermudagrass maintained at heights of cut greater than 0.5 inches, the potential exists for this treatment to selectively control seashore paspalum in those situations. However, additional research is needed before a conclusive recommendation can be made.
January 30, 2008
Continuing Research on Alternative Weed Control Methods in Seashore Paspalum
Two new research projects investigating alternative weed control methods for use in seashore paspalum are underway at Ko’olau Golf Course (Kaneohe, HI) and Kapiolani Park (Honolulu, HI). Studies at Ko’olau target hilograss (Paspalum conjugatum), while work at Kapiolani focuses on goosegrass control (Eleusine indica). Initial research in the fall of 2007 indicated that granular applications of sodium chloride can provide selective control of these two weed species with minimal turfgrass injury. LONG TERM EFFECTS OF THESE APPLICATIONS ON SOIL QUALITY HAVE NOT YET BEEN DETERMINED. It is likely that these weed control treatments may have negatively affected soil chemical properties.
Granular applications of calcium and potassium chloride may provide a similar level of efficacy without negatively affecting soil chemical properties. Applications of calcium, potassium, and sodium chloride are being evaluated at various rates against standard herbicides such as MSMA, Sencor (metribuzin), and Revolver (foramsuluron). Turfgrass injury and weed control data will be monitored weekly for 8 weeks after treatment. Soil chemical properties, before and after treatment, will be measured as well. Updates (with plot images) will be posted throughout the experiment.
Chemical Strategies for Controlling Seashore Paspalum
A study is underway at the Windward Community College Golf Instructional Facility evaluating both non-selective and selective techniques for controlling seashore paspalum. Treatments include Roundup Pro (glyphosate), Fusilade II (fluazifop), and Basamid (dazomet), applied alone and in combination with one another. If effective, these treatments may be suited for non-selective control when renovating areas of seashore paspalum. Combinations of MSMA, Sencor (metribuzin), Revolver (foramsulfuron), and Confront (triclopyr + clopyralid) will be evaluated as well. If effective, this latter set of treatments may serve as tools for selectively controlling seashore paspalum in bermudagrass (Cynodon sp.) Turfgrass injury, chlorophyll content, and percent ground cover will be measured weekly for 8 weeks after treatment. Thanks go out to Advan LLC for their financial support of this research effort.