Chapter 1. Turfgrass Science

1. Introduction

• 1-1. Definitions

• Turfgrass : Plants that form a more or less contiguous ground cover that persists under regular mowing and traffic.

• Basic requirements for turfgrass ① Plants to maintain acceptable quality under continuous mowing ② Plants to stand regular traffic ③ Plants to grow low

• Turfgrass Quality : Visual quality and Func-tional quality

• Visual quality - density, texture, uniformity, color,

growth habit and smoothness• Functional quality - rigidity, elasticity, re-

siliency, yield, verdure, rooting, recuperative capacity

• Turf : An interconnecting community of turfgrasses and the soil adhering to their roots and other belowground organs from a turf.

• Lawn : Turfgrass field in a landscape Lawn turf, Sports turf, Utility turf

• Sod : Surface layer of a turf harvested for transplanting

1-2. Function of turf

• - Decorative : Home landscape, parks, street etc• - Functional : • Soil stabilization• Recreational activities and relaxation• Sports• Environment Protection : temperature control, toxic materials control, dust and noise control, drainage control, CO2 control, O2 production, etc

1-3. Related industries and Career opportunities

• ① Ground superintendent : golf course, athletic facility, recreational facility, institutional facility, government facility, transportation facil-

ity, business facility, residential complexes etc• ② Manufacturing/Sales representa-

tive : Equipment, Fertilizers, Pesticides, Seed, Sod and propagule, miscellaneous

• ③ Professional-service contractor : Consulting, testing, design, lawn care, landscap-

ing, construction• ④ Technical writer : trade magazines, technical journals, newsletters, commercial re-

ports• ⑤ Scientist/educator : academic institu-

tions, industrial-research operations

2. Climatic adaptation of Turfgrass

Family : Gramineae or Poaceae

6 Subfamilies 25 Tribes 600 Genera 7500 species

Subfamilies of turfgrass species

Festucoideae - Cool season grasses Optimum temperature range : 15 - 23 CPanicoideae Warm season grassesEragrostoideae Optimum temperature range : 27 - 32 C

Climate ZonesTropical : Frost free belt between 20 north and south lati-tudesSubtropical : Minimum of 8 month over 10 CTemperate : 4 - 7 month over 10 C Temperate oceanic and Temperate continental Transition zone - mostly Temperate continentalSubarcticPolarDry : Arid and Semiarid

Adaptation of turfgrass speciesCool-season turfgrasses : mainly to temperate and subarctic

Warm-season turfgrasses : mainly to tropical and subtropical

Boarder zone(about 300 km) : transition zone - Zoysiagrass and Tall fescue

3. History of turfgrass science

Evolution of grass species adapted to grazing by animals and cattle

Modern turfgrass management begins with1. 2,4-D and DDT development - 19452. New cultivars ; 'Merion' Kentucky bluegrass - 19473. Development of Core aerifier - Mid 1940s4. Many turfgrass species and cultivars Scientific turf management techniques Automatic equipment development Specific pesticides

4. The grass plants

4-1. Diagram of the grass plant

-growth habbit

4-2. leaf morphology- leaf sheath and leaf blade- ligule : A membranous or hairy structure at the junction of the blade and the sheath on the inner side, varying in size and shape

- collar : A light green or whitish band at the opposite side of the ligule

- auricle : Two clawlike appendages at the base of leaf blade

- vernation : The shape of new emerging leaf, folded or rolled

4-2. stems- tiller, stolon and rhyzome- flowering culm

4-3. inflorescence- spike, panicle and raceme