Seeding Methods

You can achieve uniform application by making two passes over the area in opposite directions. Seeding this way masks any skips in the first pass.

When seeding in two directions, calibrate the spreader to deliver one half of the seed in each of the two passes.

Seed-to-soil contact

Good seed-to-soil contact is important for seed germination because it enables the seed to absorb water. Seeds must be kept moist and have a place to anchor for establishment to occur.

Providing good seed-to-soil contact prevents seed from drying out quickly and it also enables the seed to root into the soil more rapidly.

Seed-to-soil contact is not favourable with broadcast or drop spreaders. You need to work the seed in by lightly raking it into the top 5-10mm of the soil and then follow this up by rolling to firm the soil and increase the seed-to-soil contact.

The raking and rolling steps are not necessary with a disc seeder or roller drill because seed is placed or worked into the soil.

Seed depth

Most turfgrass seeds are quite small and so they should be sown at a fairly shallow depth in the soil. Sow them 5-6mm below the soil surface for rapid germination. If you sow them deeper than 10mm, you are likely to get poor seedling emergence.

Another alternative, particularly with small seeds like browntop, is to sow the seed on the surface, cover it with a light topdressing of soil and then roll it.

Pregerminated seed

You can speed up seed germination by several days by using a technique known as pregermination. This technique involves immersing the seed in large quantities of water to start the germination process. The inclusion of soluble urea fertiliser into the wash water will also greatly speed things up and may reduce germination of Penncross bentgrass to 3 - 5 days rather than 7 - 21 days. The amount of urea added is in parts per million and is determined by the quantity of water used.

Mixture to be used

Urea should be added at the rate of 200 ppm for bentgrass. Because one ml - one gram; then 200 grams of urea will need to be dissolved into 1,000 litres of water (or 100 gms into 500 litres) to get the correct proportion. DO NOT USE sulphate of ammonia, calcium ammonium nitrate or others.

Steps to follow

Dissolve urea in warm water and add to a large tank.

Then add seed, saturate thoroughly and leave in solution for 4 hours. Remove, drain well and air dry well and quickly. DO NOT store damp seed. It can be held for no longer than a week, and should be used in 1 - 5 days. For best results immerse seed in fresh solution every 2 hours; do not use running water and do not rinse.

Seed	Urea (ppm)	Time (hours)
Creeping bentgrass	200	4 - 6
Red fescue	200 - 400	4 - 8
Hard or sheep's fescue	400	4 - 8
Tall fescue	400 - 600	6 - 8
Perrenial ryegrass	400 - 600	6 - 8
Annual ryegrass	400 - 800	6 - 8
Kentucky bluegrass	600 - 800	10 - 12
Rough bluegrass	400 - 600	6 - 10
non-hulled Bermuda	1000 - 1200	12 - 18

Good seed-to-soil contact will be essential because treated seed will develop rapidly. These seedlings will be prone to drought or disease stress and should be watched carefully. You can add 25 gm of fungicide for each kg of seed after drying. Thoroughly mix one of these fungicides: Ridomyl MZ72, Alliete, Plantvax, Banrot, Bravo if wettable powder is available. Do not use systemics such as Bayleton. Thiram may scorch seed. Dithane M-45, M-22 can be used.

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Sowing Guidelines

Calculation of seeding rates. For example:

% Pure live seed (PLS) = % pure seed x % germination x 100

PLS = 0.98 x 0.90 x 100

= 88.2%

So, if the seeding rate for ryegrass is 390 kg per hectare, you would have to use ...

(390/1) x (100/88.2) = 442.17 kg

The table (following) shows sowing guidelines for golf courses. The numbers given for seed purity and seed germination are the preferred minimum percentage. When you use seed mixtures, use a seeding rate between the two extremes for each of the turfgrass species making up the seed mixture. Use the lower seeding rate for each turfgrass species in the rough if the budget is restricted and rapid turf establishment with minimum weeds is not a high priority. When you are overseeding thin turf, you can use 30% to 50% of the listed rates.

Turfgrass	Minimum Seed Purity %	Minimum Seed Germination %	Rate in kg/ha for greens, tees, fairways & rough seeding
Browntop	95 - 98	85 - 90	22 - 50
Creeping bent	95 - 98	85 - 90	22 - 50
Chewing's fescue	95 - 97	80 - 85	170 - 200
Red fescue	95 - 97	80 - 85	170 - 200
Tall fescue	95 - 98	85 - 90	300 - 390
Kentucky bluegrass	90 - 95	75 - 80	50 - 73
Perennial ryegrass	95 - 98	90 - 95	300 - 390

In more southern parts of the South Island and the central plateau of the North Island, where autumn is a comparatively short season and there may be heavy frosts, sowing at this time is rather hazardous. In fact, seedling turf could be completely destroyed by the heavy frosts. Consequently, in those localities, sow seed in mid-spring, when the danger from heavy frosts has passed. However, weed seedlings can be a problem with spring sowing.

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Sowing Summary

Almost all cool-season grasses are propagated by seed.

The seeding rate depends on:

1. The number of seeds per kilogram,
2. How pure the seed is,
3. How much of the pure seed will germinate, and
4. The growth habits of the turfgrass species you use.

 

Other considerations include:

1. Whether the environmental conditions are suitable for germination,
2. How well the seedbed is prepared, and
3. The cost of the seed.

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Turf Guide for Improved Turfgrasses

Species	Growth habit TD	Establish Rate	Nitrogen Requirement	Mowing Frequency	Close Mowing Tolerance (7mm or less)	Traffic Tolerance	Drought Tolerance
Improved Turf-type Kentucky Bluegrass		Slow	Medium	Low to Medium	Fair	Good	Good
Improved Turf-type Perennial Ryegrass	Bunch type	Very fast	Medium to high	High	Very good	Excellent	Very Good
Improved Hard Fescue	Bunch type	Slow to medium	Low	Low	Poor	Good	Excellent
Improved Chewings Fescue	Bunch type	Medium	Low to medium	Low to medium	Good	Fair	Good
Improved Creeping Fescue	Spreads by rhizomes	Medium	Low to medium	Low to medium	Poor	Poor	Good
Improved Tall Fescue	Bunch type	Medium	Medium	Medium	Poor	Very good	Excellent
Improved Creeping Bentgrass	Spreads by Stolons	Medium	Low to medium	Low to medium	Excellent	Good	Poor to fair

 

Species	Drought Tolerance	Competiveness	Thatch Formation	Shade Tolerance	Cold Tolerance	Seeding Rate/100 sq.m
Improved Turf-type Kentucky Bluegrass	Good	Medium	Medium to high	Fair to good	Very good	1 - 1.4kg
Improved Turf-type Perennial Ryegrass	Very Good	High	None	Fair to good	Fair to good	3 - 5kg
Improved Hard Fescue	Excellent	Medium	Medium	Very good	Very good	1.5 - 2.5kg
Improved Chewings Fescue	Good	High	Medium to high	Very good	Very good	1.5 - 2.5kg
Improved Creeping Fescue	Good	Medium	Low to medium	Very good	Very good	1.5 - 2.kg
Improved Tall Fescue	Excellent	Medium	Low to none	Good	Good	3 - 5kg
Improved Creeping Bentgrass	Poor to fair	High	High	Fair	Excellent	0.6 - 0.8kg

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Approximate Number of Seeds per Kilogram

Species	Number of seeds per kilogram
Browntop	19,223,985
Creeping bent	13,526,917
Chewing's and red fescue	900,794
Tall fescue	455,401
Kentucky bluegrass	3,067,703
Perennial ryegrass	530,467

*Can vary up to 10% depending on the cultivar