Bermudagrass Growth, Total Nonstructural Carbohydrate Concentration, and Quality as Influenced by Nitrogen and Potassium

Abstract

ential responses to N and K fertilization rates. Liberal N fertilization has increased shoot growth in numerous Hybrid bermudagrass cultivars (Cynodon dactylon L. ؋ C. transbermudagrass cultivars (Burton and Jackson, 1962; Wilvaalensis Burtt-Davy) differ in their responses to N and K for growth, total nonstructural carbohydrate (TNC) concentration, and turf qual-kinson and Langdale, 1974). Enhanced shoot growth ity scores. This 1995 research was conducted in Florida to compare has been at the expense of root growth in various turf responses of two bermudagrass cultivars to N and K under long-day species (Adams et al., 1974; Goss and Law, 1967; Madi-(Ͼ13 h) and short-day (Ͻ13 h) conditions in a glasshouse. Evaluations son, 1962), although Horst et al. (1985) reported inwere made concerning shoot and root growth, TNC concentration, and creased root growth in response to N at rates up to 4.9 quality scores of 'FloraDwarf ' and 'Tifdwarf ' bermudagrass during g m Ϫ2 per growing month on 'Santa Ana' bermudagrass. establishment in a coarse sand medium. Experimental design under Potassium at rates up to 22.4 g K m Ϫ2 yr Ϫ1 increased each photoperiod was a randomized complete block with factorial root or rhizome weights in 'Coastal' bermudagrass (Keitreatments consisting of two cultivars, four rates of N, four rates sling et al., 1979). Shoot growth in Coastal increased of K, and four replications. Data were analyzed by fitting multiple with up to 14.0 g K m Ϫ2 (Belesky and Wilkinson, 1983) regression equations starting with a second order polynomial model. Growth of FloraDwarf was highly responsive to photoperiod, in that and up to 41.9 g m Ϫ2 (Cripps et al., 1989). 'Tifton 44' decreased daylengths reduced growth. No growth differences were increased shoot and root growth in response to 14.0 g found in Tifdwarf due to daylength. Growth increased in response to K m Ϫ2 (Belesky and Wilkinson, 1983). N in both cultivars, while growth response to K varied by cultivar. Differential responses also have been reported for Both cultivars accumulated higher levels of TNC under short day quality in response to N and K. Quality and density in conditions, with higher levels in FloraDwarf. Nitrogen fertilization 'Tifway' increased up to 20 g N m Ϫ2 yr Ϫ1 (Johnson et al., reduced TNC levels in FloraDwarf under short days and in Tifdwarf 1987) and promoted early spring green up in 'Tifgreen' under long days, while K fertilization reduced TNC levels in Tifdwarf (Reeves et al., 1970). Potassium fertilization has inunder short days. Quality scores in both cultivars increased in response creased resistance to cultural stresses such as wear, soil to N under long days, and in response to both N and K under short compaction, and cold temperatures (Carrow et al., 1987; days. Results of these studies indicated that growth, TNC accumulation, and quality differed due to cultivar, photoperiod, and rates of Juska and Murray, 1974). N and K.

Effects of temperature and photoperiod on postponing bermudagrass (Cynodon dactylon [L.] Pers.) turf dormancy

“…Reducing temperature from 7.5 • C to −7.5 • C decreased shoot length 20, 30 and 64% compared to 15 • C, SDL. In LDL condition at 15 • C, shoot length had 350% increase compared to −7.5 • C. The results of our investigation are in agreement with Trenholm et al (1998), who found that shoot growth of 'Flora Dwarf' bermudagrass under SDL condition decreased 41% compared to LDL conditions both grown under similar temperatures. However, Marousky et al (1992) reported that 'Tif Dwarf' bermudagrass had no significant decrease in shoot growth in response to LDL condition.…”

“…palustris Huds increased due to day length extension. Whereas Trenholm et al (1998) reported adverse results on 'Flora Dwarf' and 'Tif Dwarf' cultivars of bermudagrass in similar photoperiodic condition. They reported that root production decreased 61% in response to extended day length compared to SDL condition.…”

Tifway Bermudagrass Response To Potassium Fertilization

“…2). Trenholm et al (1998) reported a 13% reduction in Tifdwarf bermudagrass root growth when the day and July, and the lowest root weights occurred during August, September, and October. In (Ͼ13 h) conditions and increased Tifdwarf root growth under short day (Ͻ13 h) conditions.…”

Nutrient uptake in tropical turfgrasses growing in winter in southern Queensland

“…Leaf N concentrations were 3.1, 3.8 and 4.0% with increasing applications, with leaf colour generally better after N. The fertilised grasses in our experiment had a mean N concentration of 3.3 ± 0.1%, whereas the unfertilised grasses had a mean N concentration of 1.7 ± 0.2% in August, suggesting a severe shortage of the nutrient after 6 months. Trenholm et al (1998) Limited data are available on the response of other grasses to N. Burton et al (1997) investigated the growth of bahiagrass in Georgia over 3 years, and found that 56, 112, 224 or 448 kg N/ha.year gave annual dry matter yields of 6.0, 8.2, 11.9 and 15.2 t/ha, associated with increasing leaf N. Cisar et al (1992) examined the performance of 'Floratam' buffalograss on an organic soil in Florida over 2 years. Nitrogen at 300 kg/ha.year increased visual quality and clipping yield of the sod, and of sod pieces re-established on sand compared with nil N controls.…”