Excessive weed competition during the establishment year is probably responsible for many stand failures. If the stand is sprigged, Diuron can be used as a pre-emergent herbicide (check the label to make sure it is legal in your state). Diuron controls many annual grasses and broadleaf weeds. It should be applied after the bermudagrass is sprigged but before it emerges. This is the only way to control most annual grass weeds when establishing bermudagrass from sprigs. Diuron cannot be used when bermudagrass is seeded. It will kill grass that emerges from seed. Always read and follow label directions when using pesticides.
Broadleaf weed control during the establishment year can be achieved with many commonly used pasture herbicides but only after the stand has developed a good root system. Read individual herbicide labels to see when they can be used. Most recommend not applying the herbicide until a certain amount of time has elapsed from planting or until the plants reach a specific growth stage.
If herbicides cannot be used and weed competition is severe, there are two possible options. You can mow the area to remove the top growth of weeds, which may allow the bermudagrass to release and grow. However, there is a possible disadvantage to mowing. If the weeds are very large and thick, the mown residue can form a mulch on the ground that may suppress bermudagrass growth as much as the standing weeds did.
Flash grazing can be used for weed control if the weeds are palatable to cattle. Watch carefully to make sure cattle are not uprooting or trampling the young bermudagrass plants.
Seed establishment
A well-prepared seedbed is critical to successfully establish bermudagrass from seed. A good seedbed should be uniformly firm; smooth; weed-free; and without clods, holes, and ridges. A firm seedbed is essential with seeded bermudagrass varieties because the seeds are very small and seeding depth is critical. If the seedbed is too fluffy, it is easy to plant seed too deep. A good way to determine if the soil is too fluffy for planting is to walk on the field that has been prepared for planting. If footprints are more than 1/4-inch deep, the soil is too fluffy.
A cultipacker or drag harrow is very helpful in establishing bermudagrass from seed. An excellent way to plant seeded bermudagrass varieties is to (1) disk and harrow the field until the seedbed is prepared, (2) cultipack the field to firm the seedbed, (3) broadcast the seed, and (4) cultipack again to press seed into the ground. Some seeders, such as a Brillion, combine steps two through four, and save two trips across the field. A drag harrow can be used in place of the cultipacker, but it generally does not work as well at firming the soil.
Bermudagrass seed may be coated or uncoated. The coatings usually contain a combination of fertilizers and fungicides. Unfortunately, the coatings usually double the weight of the seed, so the seeding rate must be doubled when using coated seeds to get the same amount of pure live seed as with uncoated seed.
Bermudagrass seed may also be sold as hulled or unhulled. Hulled seeds have part of the seed coat removed so that germination rate is enhanced. Most bermudagrass seeds are hulled. Unhulled seeds have the seed coats attached; some of the seeds will not germinate quickly but will lie dormant until conditions are more favorable. In general, if you have a good seedbed prepared and are planting at the correct time, hulled seed is preferred. If you are planting into less than ideal conditions, unhulled seed or a combination of hulled and unhulled seed is suggested.
The seeding rate for hulled bermudagrass is 5 to 10 pounds of pure live seed (PLS) per acre and 15 to 20 pounds of PLS per acre for unhulled seed. Remember that the seeding rate must be increased proportionally if the seed is coated due to the weight of the coating. Seeds usually germinate when temperatures are above 68°F and begin to grow within three weeks if temperature and soil moisture are sufficient. Growth can be very rapid if conditions are optimal, and one plant has been observed to cover an area of 3 square yards within 150 days after germination.
Sprigging
A well-prepared seedbed is usually helpful for sprigging bermudagrass, but a no-till sprigger can be used. Good contact between the sprigs and soil is essential to keep the sprigs from drying out and dying.
Some varieties of bermudagrass should be sprigged after they break dormancy in the spring (for example, Tifton 85). Many varieties can be sprigged either in the dormant season or after they break dormancy. Planting in the dormant season is usually preferred with these varieties due to better sprig survival, and they are more likely to receive rainfall during early establishment if planted during the dormant season.
Plant sprigs as soon as possible after digging, keeping them moist and cool before planting. If more than 24 hours elapses between digging and planting, soak sprigs in water for 12 to 15 hours before planting. The usual sprigging rate is 20 to 40 bushels per acre. Using the higher sprigging rate is more expensive but reduces the amount of time it takes for the stand to cover the soil.
Top-growth establishment
Bermudagrass can be established from top growth if rainfall is abundant and a sufficient growing season remains after planting. This involves cutting the grass as if for hay, baling or otherwise transporting the grass while it is green to a prepared seedbed and broadcasting it onto the field. After the grass is applied to the field, lightly disk it into the soil. For best results, run a cultipacker over it after disking to firm the soil. New plants will emerge from nodes on the grass that was applied to the field. Since this method is usually done in mid- to late summer, it requires either an irrigated environment or an environment where rainfall comes frequently.
One hundred pounds of green, uncured clippings will plant about 2,500 square feet. This means it will require about 1,750 pounds of green clippings to plant 1 acre.
Choosing an establishment method
- It is usually cheaper to establish seeded bermudagrass than sprigged bermudagrass.
- If high yield is not a large factor (for example, erosion control or turf establishment are more important), seeding is a good method.
- Stand establishment may be faster.
Disadvantages
- Seeded varieties usually have lower yields than hybrid varieties.
- Seedling bermudagrass is more negatively affected by
- dry conditions soon after emergence because of a lesser developed root system.
- Control of grassy weeds in the establishment year is difficult since Diuron cannot be used.
Sprigging
Advantages
- Hybrid varieties generally have higher yields than seeded varieties. If high yield is a major reason for planting bermudagrass, a sprigged variety is probably the answer to your goal.
- Sprigged bermudagrass can be treated with Diuron, if it’s labeled in your area. This product is very good at controlling many annual grasses that compete strongly with bermudagrass in the establishment year. If your field has heavy infestations of crabgrass, annual ryegrass, or sandbur, sprigging may be the best option since there is a pre-emergent herbicide option. There are no herbicides available to control grassy weeds in seeded bermudagrass during the establishment stage.
- Sprigged varieties usually have a more upright growth habit, which is an advantage if the grass is to be harvested for hay.
Disadvantages
- It is usually more expensive to establish a stand from sprigs.
- Specialized equipment is needed.
- Sometimes, coverage is slower since there are initially fewer plants per square foot.
Top-growth planting
Advantages
- This technique does not require digging roots and can be done with conventional hay equipment.
- Stand establishment can be very rapid if sufficient soil moisture is available.
Disadvantages
- It may require manually broadcasting grass onto the field.
- Good soil moisture in midsummer is required.
This article appeared in the April/May 2017 issue of Hay & Forage Grower on pages 20 and 21.
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