© 2005 Plant Management Network.
Accepted for publication 16 August 2005. Published 14 September 2005.
Silicon in the Life and Performance of Turfgrass
Lawrence E. Datnoff, Professor of Plant Pathology, University of Florida-
IFAS, Department of Plant Pathology, 1453 Fifield Hall, Gainesville 32611
Corresponding author: Lawrence E. Datnoff. email@example.com
Datnoff, L. E. 2005. Silicon in the life and performance of turfgrass. Online. Applied
Turfgrass Science doi:10.1094/ATS-2005-0914-01-RV.
Over the past few years there has been a growing interest in the element
silicon and its effects on the life and performance of plants. Many turfgrass
managers want more information regarding its role in plant function. This
article attempts to address that issue by first presenting general information
about silicon in soil, silicon in plants, and silicon effects on abiotic (i.e., heat
stress, drought stress, mineral toxicities, and wear tolerance) and biotic (plant
diseases and insects) stress. Then, the currently-known role of silicon in
turfgrass is explained along with mechanism(s) of silicon-mediated resistance to
plant diseases. Finally, an outlook section on the future for silicon in turfgrass
performance is presented.
Silicon in Soil
Silicon (Si) is the second most abundant mineral element in soil after oxygen
and comprises approximately 28% of the earth's crust (11,12). Despite the
abundance of Si in most mineral soils worldwide, Si deficiency can still occur
due to Si depletion from continuous planting of crops that demand high
amounts of this element, such as rice (11). Rice can uptake roughly 230 to 470 kg
of Si per ha and intensive cropping results in the removal of Si from the soil
solution at a rate faster than it can be replenished naturally (11,33). Silicon
deficiency occurs more often in highly-weathered, low-base-saturation, and low-
pH soils such as Oxisols and Ultisols which are used to cultivate upland rice in
sia, Africa, and Latin America (32).
Heavy rainfall in regions where these two types of soils occur can cause high
degrees of weathering, leaching, and desilification (33). Organic soils (Histosols)
are also deficient in plant-available Si because of the greater content of organic
matter (» 80%) and low content of minerals. Those Entisols having a high
content of quartz sand (SiO
) are also low in plant-available Si (6). Such Si-
deficient conditions may be prevalent on USGA-based quartz sand greens and
Soil solutions generally have a Si concentration of 3 to 17 mg of Si per liter
(19). This is considered low, but nevertheless it is 100 times greater than
phosphorus in most soil solutions.
Silicon in Plants
Many plants are able to uptake Si. Plants absorb Si from the soil solution in
the form of monosilicic acid, Si(OH)
, which is carried by the transpiration
stream and deposited in plant tissues as amorphous silica gel, SiO
known as opal (33,35). Depending upon the species, the content of Si
accumulated in the biomass can range from 1% to greater than 10% by weight
(11,12). Plant species are considered Si accumulators when the concentration of
Si (dry weight basis) is greater than 1% (13). Relative to monocots, dicots such as
tomato and soybean are considered poor accumulators of Si with values less that
0.1% of Si in their biomass. Terrestrial grasses such as wheat, oat, rye, barley,
sorghum, corn, sugarcane, and turfgrass contain about 1% of Si in their biomass,
while aquatic grasses have Si content up to 5% (12,13,20,25). On a weight basis,
Si is taken up at levels equal to or greater than essential nutrients such as
nitrogen and potassium in plant species belonging to the families Poaceae,
Equisetaceae, and Cyperaceae (33). Although Si has not been considered an
essential element for crop plants for lack of supportive data, species such as
quisetum and some diatomaceaes cannot survive without an adequate level of
Si in their environment (12,13). Currently, 21 plant families have been identified
as being Si accumulators (26).
Silicon Effects on Abiotic and Biotic Stress
The beneficial effects of Si, direct or indirect, to plants under abiotic and/or
iotic stress have been reported to occur in a wide variety of crops such as rice
(Oryza sativa), oat (Avena sativa), barley (Hordeum vulgare), wheat (Triticum
aestivum), cucumber (Cucumis sativus), sugarcane (Saccharum officinarum),
ornamentals (such as paper daisy, Banksia gardneri), and turfgrass (such as St.
ugustinegrass, Stenotaphrum secundatum) (10,12,13). Leaves, stems, and
culms of plants grown in the presence of Si show an erect growth, especially for
rice. This suggests that the distribution of light within the canopy is greatly
improved (11,12,33). Silicon increases rice resistance to lodging and drought,
and dry matter accumulation in cucumber and rice (1,12,22). Silicon can
positively affect the activity of some enzymes involved in the photosynthesis in
rice and turfgrass (33,34) as well as reduce rice leaf senescence (21). Silicon can
lower the electrolyte leakage of rice leaves, promoting greater photosynthetic
activity in plants grown under water deficit or heat stress (2). Silicon increases
the oxidation power of rice roots, decreases injury caused by climate stress such
as typhoons and cool summer damage in rice, alleviate frost damage in
sugarcane and other plants, and favors supercooling of palm leaves (17,33).
Silicon reduces the availability of toxic elements such as manganese (Mn), iron
(Fe), and aluminum (Al) to roots of plants such as rice and sugarcane and
increases rice and barley resistance to salt stress (23,33). Moreover, the most
significant effect of Si to plants, besides improving their fitness in nature and
increasing plant productivity, is the suppression of insect feeding and plant
Role of Silicon in Turfgrass
Fertilization with Si has shown positive effects in alleviating abiotic stress as
well as improving plant growth and development in several turfgrass species.
Since Si improves leaf and stem strength through deposition in the cuticle and
y maintaining cell wall polysaccharide and lignin polymers (19,35), the
possibility exists that Si could improve wear tolerance. Saiguisa and his
colleagues (31) demonstrated significant improved wear resistance in the
Zoysiagrass cultivar ‘Miyako.’ Foliar spraying potassium silicate at 1.1 or 2.2 kg
of Si per ha, or applying 22.4 kg/ha as a soil drench, also significantly reduced
y around 20% the injury caused by wear to seashore paspalum (36). However,
K alone or together with Si provided the same effect. In another study, several
cultivars of creeping bentgrass and Zoysiagrass had improved turf quality,
growth, and resistance to traffic and heat stress (24). Under severe drought
stress, Si-fertilized St. Augustinegrass plants had a better response than those
non-fertilized (36). Leaf firing and density were significantly greater by 13 and
23.5%, respectively, in Si-fertilized plants. Quality, color, and density also were
significantly enhanced when fertilized with Si over the controls by 19, 13.6, and
8.5%, respectively. However, under these test conditions, visual scores were all
elow what would be considered acceptable for turfgrass use. Nevertheless, this
demonstrates that Si may improve these turfgrass qualitative factors under
extreme drought stress. Schmidt and his associates (34) also showed that foliar
applications of Si significantly enhanced photosynthetic capacity increasing
chlorophyll content especially during the summer when plants were influenced
y environmental stress.
Gussak and his associates (15) demonstrated increased growth and
establishment of creeping bentgrass (Agrostis palustris Huds.) fertilized with Si.
Brecht et al. (4) and Datnoff et al. (5) also demonstrated similar results in St.
ugustinegrass. A percent bare ground coverage (vertical prostrate growth)
rating was recorded 11 to 12 weeks after sprigging a field with St. Augustinegrass
y estimating a visual percent area of bare ground covered by grass in a 2-m
area (4). They demonstrated that the final percent bare ground coverage was
significantly increased by using Si by 17 to 24% over the control. Ten months
after sprigging, one pallet containing 46 m
of St.Augustinegrass was harvested
from each treatment-silicon and a control (5). Sod pieces (mat), 30 × 61 cm,
were washed to remove soil, dried for 48 h, and weighed. In addition, fresh,
intact sod pieces (mats) from each treatment were transplanted to a sand site
and monitored for turf quality and root length development for 21 days. At
harvest, the treatment that had been fertilized with Si had a dry sod mat weight
that was 13% significantly higher than the control. Sod pieces amended with Si
also had improved turf quality ratings, 7.1 to 7.6 versus 6.6 to 7.1 in comparison
to the non-fertilized control, 14 and 21 days after being transplanted to the field.
In addition, Si treatments had a significantly greater increase in newly-
generated roots, 0.8 to 1 cm in root length, in comparison to the non-fertilized
Silicon also has been effective in suppressing diseases in a number of warm-
and cool-season turfgrass species (Table 1). Silicon has increased the resistance
of zoysiagrass to Rhizoctonia solani (31); creeping bentgrass to Pythium
aphanidermatum, Sclerotinia homoeocarpa, and R. solani (15,28,30,34,37);
and in Kentucky bluegrass to powdery mildew (Sphaerotheca fuliginea) (16).
Gray leaf spot development was reduced by Si over a range of 19 to 78% on
several cultivars of St. Augustinegrass under greenhouse conditions (7) (Fig. 1).
In field experiments, Si alone was compared to foliar sprays of chlorothalonil
and of Si plus chlorothalonil for managing gray leaf spot development (4). Gray
leaf spot was reduced by 17 to 27%, 31 to 63%, and 56 to 64% for Si alone,
chlorothalonil alone, and Si plus chlorothalonil, respectively, compared to a
non-treated control. Recently, Nanayakkara et al. (27) demonstrated similar
results in perennial ryegrass turf. They showed that gray leaf spot severity was
reduced from 11 to 24%.
Datnoff and Rutherford (9) recently evaluated the ability of Si to enhance
disease resistance in ‘Tifway’ bermudagrass to Bipolaris cynodontis, the cause o
leaf spot and melting out. They found that plants fertilized with Si had 39%
fewer lesions than plants non-fertilized (Fig. 2). This was also the first
experiment to demonstrate that bermudagrass accumulates Si. Silicon increased
in leaf tissues 38 to 105% over the control.
Fig. 1. Influence of silicon on gray leaf spot development in St.
Mechanism(s) of Silicon-Mediated Resistance to Plant Diseases
The effect of Si on plant resistance to disease is considered to be due either to
an accumulation of absorbed Si in the epidermal tissue, and/or expression of
pathogensis-induced host defense responses. Accumulated monosilicic acid
polymerizes into polysilicic acid and then transforms to amorphous silica, which
forms a thickened Si-cellulose membrane (18). By this means, a double cuticular
layer protects and mechanically strengthens plants. Silicon also might form
complexes with organic compounds in the cell walls of epidermal cells, therefore
increasing their resistance to degradation by enzymes released by fungi (8).
Research also points to the role of Si in planta as being active and this
suggests that the element might amplify the response for inducing defense
reactions to plant diseases. Silicon has been demonstrated to stimulate chitinase
activity and rapid activation of peroxidases and polyphenoxidases after fungal
infection (3). Glycosidically bound phenolics extracted from Si amended plants
when subjected to acid or B-glucosidase hydrolysis displayed strong fungistatic
activity. More recently, flavonoids and momilactone phytoalexins, low molecular
weight compounds that have antifungal properties, were found to be produced
in both dicots and monocots, respectively, fertilized with Si and challenge
inoculated by the pathogen in comparison to non-fertilized plants also
challenged inoculated by the pathogen. These antifungal compounds appear to
e playing an active role in plant disease suppression (14,29).
Table 1. Turfgrass, disease, and plant pathogen response to silicon.
Silicon applied as calcium silicate or potassium silicate decreased (<) disease
Fig. 2. Influence of silicon on Bipolaris leaf spot development in
Turfgrass Disease Pathogen Effect
Zoysiagrass Leaf blight Rhizoctonia solani < (31)
Root rot Pythium
Brown patch Rhizoctonia solani <
Dollar spot Sclerotinia
Bermudagrass Leaf spot Bipolaris cynodontis < (9)
Magnaporthe grisea < (4,7)
Magnaporthe grisea < (27)
Outlook and Future for Silicon in Turfgrass Performance
That Si plays an important role in the mineral nutrition of plant species such
as rice and sugarcane is not in doubt nor is its ability to enhance plant
development and efficiently control plant diseases. Now evidence is
accumulating that similar effects occur in certain turfgrasses. Effective, practical
means of application, affordable sources of Si, and methods for identifying
conditions under which Si fertilization will be beneficial are needed for use in
turfgrass management. However, research on the use of Si for turfgrass is in its
infancy. For example, no soil tests for gauging amounts of plant-available Si
have been calibrated for turfgrass. Furthermore, most analytical laboratories do
not routinely assay plant tissue for Si. In fact, the current standard tissue
digestion procedures used in most laboratories would render Si insoluble,
making an analysis of the digested tissue meaningless. Thus, the two analytical
tools most often used for determining the need for fertilization with plant
nutrients are not widely available for Si. While a number of beneficial responses
of turfgrass to Si applications have been documented in controlled experiments,
particularly in the laboratory, few large-scale field effects have been observed to
date. Conditions under which beneficial responses to Si fertilization will occur
are not well known for turfgrass.
Nevertheless, as the need for environmentally friendly strategies for
management of abiotic and biotic stress increases, Si could provide a valuable
tool for use in plants capable of its accumulation. The use of Si for improving
plant performance while controlling plant diseases in turf would be well-suited
for inclusion in integrated pest management strategies and would permit
reductions in fungicide use. As researchers and turfgrass managers become
aware of Si and its turf potential, it is likely that this often overlooked element
will be recognized as a viable means of enhancing turfgrass health and
1. Adatia, M. H., and Besford, R. T. 1986. The effects of silicon on cucumber plants
grown in recirculating nutrient solution. Ann. Bot. 58:343-351.
2. Agarie, S., Agata, W., and Kaufman, P. B. 1998. Involvement of silicon in the
senescence of rice leaves. Plant Prod. Sci. 1:104-105.
3. Bélanger, R. R., Bowen, P. A., Ehret, D. L., and Menzies, J. G. 1995. Soluble silicon:
Its role in crop and disease management of greenhouse crops. Plant Dis. 79:329-
4. Brecht, M. O., Datnoff, L. E., Kucharek, T. A., and Nagata, R. T. 2004. Influence of
silicon and chlorothalonil on the suppression of gray leaf spot and increase plant
growth in St. Augustinegrass. Plant Dis. 88:338-344.
5. Datnoff, L., Brecht, M., Kucharek, T., Trenholm, L., Nagata, R., Snyder G., Unruh,
B., and Cisar, J. 2005. Influence of silicon (Si) on controlling gray leaf spot and
more in St. Augustinegrass in Florida. TPI Turf News 3:30-32.
6. Datnoff, L. E., Deren, C. W., and Snyder, G. H. 1997. Silicon fertilization for disease
management of rice in Florida. Crop Prot. 16:525-531.
7. Datnoff, L. E., and Nagata, R. T. 1999. Influence of silicon on gray leaf spot
development in St.Augustinegrass. Phytopathology 89:S19.
8. Datnoff, L. E., and Rodrigues, F. A. 2005. The role of silicon in suppressing rice
diseases. Online. February APSnet Feature. American Phytopathological Society,
St. Paul, MN.
9. Datnoff, L. E., and Rutherford, B. A. 2004. Effects of silicon on leaf spot and melting
out in bermudagrass. Golf Course Manage. 5:89-92.
10. Datnoff, L. E., Snyder, G. H., and Korndorfer, G. H. 2001. Silicon in Agriculture.
Elseveir Science, The Netherlands.
11. Elawad, S. H., and Green, V. E. 1979. Silicon and the rice plant environment: A
review of recent research. Riv. Riso 28:235-253.
12. Epstein, E. 1994. The anomaly of silicon in plant biology. Proc. Natl. Acad. Sci. USA
13. Epstein, E. 1999. Silicon. Annu. Rev. Plant Physiol. Plant Mol. Biol. 50:641-664.
14. Fawe, A., Abou-Zaid, M., Menzies, J. M., and Bélanger, R. R. 1998. Silicon-
mediated accumulation of flavonoid phytoalexins in cucumber. Phytopathology
15. Gussack, E., Petrovic, M., and Rossi, F. 1998. Silicon: The universal contaminant.
Turfgrass Times 9:9-11.
16. Hamel, S. C., and Heckman, J. R. 1999. Impact of mineral silicon products on
powdery mildew in greenhouse grown turf. Rutgers Turfgrass, vol. 31, Rutgers,
17. Hodson, M. J., and Sangster, A. G. 2002. Silicon and abiotic stress. Pages 99-104
in: Second Silicon in Agriculture Conference. T. Matoh, ed. Press-Net, Kyoto,
18. Hodson, M.J., and Sangster, A. G. 1988. Silica deposition in the influence bracts of
wheat (Triticum aestivum). 1 Scanning electron microscopy and light microscopy.
Can. J. Botany 66:829-837.
19. Hull, R. J. 2004. Scientists start to recognize silicon’s beneficial effects. Turfgrass
20. Jones, L. H. P., and Handreck, K. A. 1967. Silica in soils, plants and animals. Ad.
21. Kang, Y. K. 1980. Silicon influence on physiological activities in rice. Ph.D. diss.,
University of Arkansas, Fayetteville, Arkansas.
22. Lee, K. S., Ahn, S. B., Rhee, G. S., Yeon, B. Y., and Park, J. K. 1985. Studies of silica
application to nursery beds on rice seedling growth. Farm Product Utilization
23. Liang, Y. C., Shen, Q. R., Shen, Z. G., and Ma, T. S. 1996. Effects of silicon on
salinity tolerance of two barley cultivars. J. Plant Nutr. 19:173-183.
24. Linjuan, Z., Junping, J., Lijun, W., Min, L., and Fusuo, Z. 1999. Effects of silicon on
the seedling growth of creeping bentgrass and zoysiagrass. Pages 381 in: Silicon in
Agriculture. L. E. Datnoff, G. H. Snyder, and G. H. Korndorfer, eds. Elsevier
Science. Amsterdam, The Netherlands.
25. Ma, J., Nishimura, K., and Takahashi, E. 1989. Effect of silicon on the growth of
rice plant at different growth stages. Jpn. J. Soil Sci. Plant Nutr. 35:347-356.
26. Ma, J., and Takahashi, E. 2002. Soil, fertilizer and plant silicon research in Japan.
Elseveir Science, The Netherlands.
27. Nanayakkara, U. N., Uddin, W., and Datnoff, L. E. 2005. Effects of silicon on
development of gray leaf spot in perennial ryegrass turf. Phytopathology 95:S172.
28. North Carolina State. 1997. Effect of soluble silica on brown patch and dollar spot
of creeping bentgrass. No. Carolina Turfgrass, Aug./Sept.:34-36.
29. Rodrigues, F., McNally, D., Datnoff, L., Jones, J., Labbé, C., Benhamou, N.
Menzies, J., Bélanger, R. 2004. Silicon enhances the accumulation of diterpenoid
phytoalexins in rice: a potential mechanism for blast resistance. Phytopathology
30. Rondeau, E. 2001. Effect of potassium silicates on disease tolerance of bentgrass.
Seminaire de fin d’etudes, Centre de Recherche en Horticulture, Université Laval,
31. Saigusa, M., Onozawa, K., Watanabe, H., and Shibuya, K. 2000. Effects of porous
hydrate calcium silicate on the wear resistance, insect resistance, and disease
tolerance of turf grass "Miyako". Grassland Sci. 45:416-420.
32. Savant, N. K., Datnoff, L. E., and Snyder, G. H. 1997. Depletion of plant-available
silicon in soils: A possible cause of declining rice yields. Commun. Soil Sci. Plant
33. Savant, N. K., Snyder, G. H., and Datnoff, L. E. 1997. Silicon management and
sustainable rice production. Pages 151-199 in: Advances in Agronomy, vol. 58. D.
L. Sparks ed. Academic Press, San Diego, CA.
34. Schmidt, R. E., Zhang, X., and Chalmers, D. R. 1999. Response of photosynthesis
and superoxide dismutase to silica applied to creeping bentgrass grown under two
fertility levels. J. Plant Nutr. 22:1763-1773.
35. Takahashi, E., Ma, J. F., and Miyake, Y. 1990. The possibility of silicon as an
essential element for higher plants. Comments Agric. Food Chem. 2:99-122.
36. Trenholm, L. E., Datnoff, L. E. and Nagata, R. T. 2004. Influence of silicon on
drought and shade tolerance of St. Augustinegrass. HortTechnology 14:487-490.
37. Uriarte, R. F., Shew, H. D., and Bowman, D. C. 2004. Effect of soluble silica on
brown patch and dollar spot of creeping bentgrass. J. Plant Nutri. 27:325-339.