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Weeds at the Hong Kong Golf Club

September 29, 2010

Recently I have been getting e-mails from friends and family back in Iowa telling me about all the weed pressure this season from the wet weather conditions. Their messages got me thinking about some of the weeds around here in Hong Kong and I thought it would be interesting to share about three different types of weeds that are an ongoing battle for us here at the Hong Kong Golf Club.

Goosgrass Eleusine indica
Goosegrass is a summer annual grass, which grows as a perennial here in our subtropical climate. Goosegrass pressure is intense on nearly all parts of the course and grows very well in compacted and high traffic areas. Recently, a pre-emergent herbicide plan has been implemented using Barricade and we have had great success. By using this pre-emerge program in the fairways, roughs and all other major play areas, we have saved a massive number of man-hours that were devoted to hand pulling weeds. We still have a crew of who spends a majority of their day walking the fairways with a weed removing tool and a trash bag trying to control the Goosegrass. At the end of the day most of the managers have filled up the back of their carts from pulling Goosegrass on their courses whenever they see a troublesome clump trying to take over.

Water Hyacinth Eichhornia crassipes
Water Hyacinth is a water dwelling weed that is incredibly invasive and can destroy the make up of a pond or lake. It quickly covers the entire top of a body of water, cutting out sunlight to lower levels, and sucks all the oxygen out. There was an article in the August edition of Golf Course Management (pg 40) about a new insect that they believe will help control populations of Water Hyacinth. Unfortunately, the insect is just being released in Florida and I do not know if it will ever be made useful here in South East Asia. Our current control method is again, manual removal. Every few months our landscape team will go in and remove all the Water Hyacinth from this pond. Unfortunately, if you leave just one leaf, it will be completely covered again. We are keeping our fingers crossed it does not invade other ponds on the course.

“Creeper” Mikania micrantha
Chinese Creeper, or more commonly known just as “Creeper” is a weed that has most of Hong Kong in its grips, literally. Creeper is a perennial weed that quickly grows and overtakes trees and all other vegetation. It smothers them from the light and eventually kills them. This vine can be seen taking over forests in the mountains and if anything sits for too long, creeper will eventually overtake it. Our arboriculture team regularly removes the vine from our tree lines here at the golf course. They do a great job keeping it from overtaking our natural areas, but it is a never-ending job. There are some chemical controls for it, but it is easiest and safest to just remove by hand and to try and keep populations at a minimum so it doesn’t get out of control.

Damian Richardson
Hong Kong Golf Club


Unusual September Weeds and Diseases in Iowa

September 24, 2013

With last week’s abnormally warm September weather, several diseases and weeds were discovered around the state of Iowa. Brown patch thrived with night temperatures above 70F⁰ coupled with high humidity. Brown patch is caused by the fungal organism Rhizoctonia solani. Damage affects the leaf blade from the tip down and is usually noticed in grasses which receive high amounts of nitrogen fertilization. Symptoms are straw colored irregularly shaped foliar lesions with a brown boarder. R. Solani can attack most cool-season grasses, but is most commonly noticed on creeping bentgrass greens, tall fescue lawns and Kentucky bluegrass.

Symptoms on bentgrass putting greens appear as a copper/gray-colored “smoke rings” ranging from a few inches to several feet where mycelium can be seen. Figure 1 below was taken last week by Dan Strey at the ISU research station. Figure 2 is from University of Missouri Extension IPM: Identification and management of turfgrass disease - looking at leaf and sheath lesions of brown patch.  


Figure 1: Brown Patch at ISU research station
Figure 2: University of Missouri publication looking at tall fescue foliar syptoms of brown patch


There are many fungicides that provide brown patch control such as Daconil, Banner Maxx, Heritage, and several others. Cultural practices such as reducing nitrogen levels and preventing long periods of wet conditions can reduce disease pressure. With temperatures tapering off over the weekend, hopefully it will be the end to the high temperature summer diseases in Iowa.

Oddly enough, in the middle of September we have also seen crabgrass and goosegrass seedlings germinating at the ISU research farm. Normal crabgrass germination occurs in mid-April to mid-May depending on your location in the state. Crabgrass is easily identified with fine hairs on the leaves and sheaths as well as its distinctive “protruding fingers” seedheads. Crabgrass also has a rolled vernation, while goosegrass has a folder vernation. 

Goosegrass is often mistaken for crabgrass and some people incorrectly refer to it as “silver crabgrass” because if it’s silvery appearance of the lower sheaths.  Goosegrass generally germinates 2-3 weeks later than crabgrass in the spring. The seed stalks of goosegrass also appear somewhat like a zipper with two individual seeds protruding in two directions. In figure 3 and 4 below you will see the side by side comparison from the Scotts grass manual.

Figure 3 and 4: Goosegrass and Crabgrass comparison from Scotts grass manual

Goosegrass is very difficult to control, even with the use of preemergence herbicides. The best postemergence option is a nonselective herbicide such as glyphosate. Optimal crabgrass postemergence control is obtained when applied while the crabgrass is small and actively growing. The use of fenoxyprop, quinclorac, and dithiopyr are the best options.