Presentation on theme: "Herons Glen Greens Update. History Typical life span of a green in South Florida with Ultra dwarf Bermudagrass is 10 – 15 years. Herons Glens Greens."— Presentation transcript:
History Typical life span of a green in South Florida with Ultra dwarf Bermudagrass is 10 – 15 years. Herons Glens Greens Renovated in 2006 with Tif-Eagle Ultra dwarf Bermudagrass built to USGA specifications.
Decline in Green Health Main reason is excessive organic matter buildup in root zone. A buildup of organic matter is a gradual process that occurs when the rate of plant-deposited biomass exceeds the rate of microbial decomposition and the physical removal through aerification and verticutting.
What does this mean? As the grass grows, naturally, parts of the plant including roots begin to decompose in the upper ½ inch of the soil. As they break down the plant material turns into thatch and eventually organic matter. Without physically removing the thatch, the layer of organic matter continues to grow and eventually will encompass the entire root zone. As organic matter grows, it eliminates space for air and increases the water holding capabilities of the root zone. Without air, the soil begins to create toxic gasses such as Sulfur and Carbon Dioxide. The increased water, combined with gasses will eventually suffocate the plant.
Aerification Opens up pore space, allowing the soil to breath. Replace built up organic matter with USGA sand.
Verticutting Removing the uppermost layer of thatch before it has a chance to break down into organic matter. Opens up channels for new sand to be incorporated into soil profile. Reduces “grain” in the green. Creates smoother greens.
Topdressing Incorporating new sand into the root zone. Helps to minimize thatch and break down organic matter. Creates a firmer, smoother putting surface.
Excess Fertilization Excessive Nitrogen causes rapid growth in the plant, thus creating more plant material which ultimately turns into thatch. Tif-Eagle requires approximately 1 lb. Nitrogen/1000 ft 2 /growing month.
Compaction Most difficult to manage. Caused by equipment and foot traffic. Core aeration in summer. “Pencil” tines or venting in winter months.
What does organic matter look like? #6 Green January 2005
What does this mean? Current aerification practices are helping but not enough. Weekly sand topdressing is helping to dilute the organic matter in the upper 3 inches of the root zone but we must continue this practice.
What can we do? Increase number of core aerifications in the summer. Perform double aerification in June and July. Will require closing on Monday and Tuesday during these 2 weeks. Will require additional temp. labor on Monday and Tuesday during these aerifications. Greens will have double the amount of holes in them requiring additional time to fully recover. Proposed Aerification Dates: May 6 th June 10 th (Double) July 15 th (Double) August 19 th
Shade Bermudagrass requires 8-10 hours of direct sunlight/day. Morning sun is especially important to dry grass from overnight irrigation and dew. Excess moisture creates disease, shallow roots and algae.
Consequences Shade combined with high organic matter in the soil = recipe for disaster! Root zone never has a chance to dry out resulting in even more organic matter. Ultimately loss of grass is inevitable.
What can we do? Trimming trees is simply not enough. Removal of select trees becomes necessary.
Contamination Contamination occurs when foreign grasses, typically from the collar grow in the putting surface. Most often begins during grow in process. Causes uneven, inconsistent putting surface.
What can we do? In severe cases often times it is too late. Must be controlled during grow in process. Foreign grasses need to be physically removed early on when plant is small to prevent spreading. Very noticeable when dew present.
Encroachment The grass from the collar creeps into the putting surface decreasing the size of the green. Greens can easily shrink up to 25% over a period of time if not controlled. Allows foreign grass to find its way into the middle of the green via mowing equipment.
What can we do? Green perimeters must be stick edged almost weekly beginning with the grow in process. Manually remove “runners” from putting surface. Encroachment is so severe that the affected green perimeter along with a portion of the collar would have to be sod cut to a depth of up to 6 inches. New soil added and re-sprigged. This process is very time consuming and labor intensive. Sprigs must be continuously hand watered when first planted for up to a month. Perimeters of greens would have to remain free from foot traffic until fully grown in, approximately 90 days. In my best estimation, using in house labor and materials we would only be able to repair 2-3 greens in a summer. In my opinion, given the current condition of the greens, spending large amounts of time, money and labor to correct the encroachment problem would not be cost effective.
Nematodes Nematodes are unsegmented roundworms, different from earthworms that are segmented. Only visible through a microscope. As Nematodes feed on the root system of the plant they reduce the ability of the grass to obtain water and nutrients from the soil. Over-compaction reduces oxygen penetration to the root system and enhances susceptibility to nematode damage. Excessive nitrogen fertilization can increase succulent root growth and tips which are more susceptible to nematode damage. The threshold for “Sting” Nematodes in Bermudagrass is 10-25/ft 3 of soil. Soil tests performed on Putting Green, numbers: 1,2,6,8 and 10 in October of 2012 show Sting Nematode levels of 88 – 144/ft 3 of soil.
What can we do? Increased cultural practices Aerification Sand Topdressing Limiting Nitrogen Fertilization Chemical Control Nemacur Highly effective No longer available. Banned by E.P.A. Currently using Neo-Tec Sesame Oil Does not kill Nematode, simply protects the root from damage. Results have been positive however, Large number of Nematodes still present in the soil.
What can we do? Soil Fumigant Curfew is only available fumigant that can be applied safely to turf. It is injected into soil with specialized machinery. Some surface damage can be expected from machinery and gases coming to the surface. Has a re-entry period of 24 hours. Kills all nematodes present in soil at time of application. Does not have any residual effect. Possibility of Nematodes returning. We will be applying Curfew to our greens on Monday, May 20 th. Putting Green and numbers 1-10 will be treated. Notices will be sent out via newsletter and e-mail as we get closer. Signage will be posted in numerous spots on every hole.
Back to the beginning Herons Glen greens built in 2006 Expected life span of Ultra Dwarf Bermudagrass green in Southwest Florida 10-15 years.
Take home message Increased aerification is a must to manage organic matter. Continue sand topdressing and verticutting. Manage shade issues by removing select trees. Prepare for greens renovation in the future.