Applied Turfgrass Science最新文献

This study was conducted on an annual bluegrass (Poa annua L.) putting green and examined the effects on ball roll distance (BRD) from five mowing and rolling frequency regimes using both a light and heavy roller with and without Primo Maxx. Treatments included: (i) mow daily with no rolling; (ii) mow daily + roll M, W, F; (iii) mow daily + roll daily; (iv) mow M, W, F, Sa + roll daily; and (v) alternate mowing and rolling daily. For six weeks during the summers of 2009 and 2010, ball roll distances were measured in the morning and afternoon, Monday through Friday. BRD decreased an average of 0.5 ft from the morning to the afternoon. The heavy roller significantly increased BRD in 2009 by 0.4 ft or less, but not in 2010. Primo Maxx increased BRD an average of 0.5 ft in 2010, but not in 2009. Mowing + rolling daily produced the longest BRD followed by mow daily + roll M, W, F and mow M, W, F, Sa + roll every day which was 0.5 ft less. Mow daily with no rolling and alternate mowing and rolling daily had the shortest BRD averaging 1.2 ft less than mowing and rolling daily.

Corn gluten meal (CGM) is a naturally derived weed control/fertilizer that may allow for reduction in herbicide use on turfgrass. Previously it has been reported that CGM inhibits root production and reduces naturally occurring weed populations. It is unclear if weed population reductions are due to herbicidal activity or increased competition of the turfgrass species from nitrogen in CGM. Our objective was to compare three N sources (CGM, Milorganite, and urea) with three application strategies (equivalent of 1.8 lb N/1000 ft² with half applied in spring plus half applied in fall, 3.6 lb N/1000 ft² with half applied in spring plus half applied in fall, and 3.6 lb/1000 ft² applied in spring). CGM provided equivalent or lower quality ratings compared to Milorganite or urea throughout the two-year study. Common dandelion (Taraxacum officinale G.H. Weber ex Wiggers) counts (0 to 1004/100 ft²) and smooth crabgrass [Digitaria ischaemum (Shreb) Shreb. ex Muhl.] coverage (5 to 90%) were similar for treatments receiving CGM, Milorganite, and urea. In this study, CGM provided no additional benefit in weed control compared to products containing only N. Fertilizing with 3.6 lb of N/1000 ft² resulted in higher turf quality with less weeds than plots receiving only 1.8 lb of N/1000 ft².

Field experiments were conducted in Texas to examine the recovery of a bermudagrass [Cynodon dactylon × C. transvaalensis (L.) Pers.] fairway from spring dead spot (SDS) disease following preemergence (PRE) herbicide applications. In 2011 and 2012 bermudagrass recovery from SDS in the non-treated check plots (46 and 59%, respectively) was similar to bermudagrass recovery in response to oxadiazon at 3.4 kg/ha (55 and 57%, respectively) 14 weeks after treatment (WAT). Pendimethalin at 2.5 kg/ha resulted in 33 to 38% bermudagrass recovery from SDS 14 WAT. In 2011, oryzalin (1.68 kg/ha), dithiopyr (0.56 kg/ha), prodiamine (0.73 kg/ha), and dimethenamid (1.68 kg/ha) applications resulted in 21 to 25% bermudagrass recovery from SDS 14 WAT. In 2012, bermudagrass exhibited similar recovery in response to prodiamine and oryzalin (24 and 26%, respectively), while response to dithiopyr and dimethenamid was 33 and 34%, respectively, 14 WAT. Bermudagrass exhibited the least amount of recovery (13 to 14%) in response to indaziflam at 0.035 kg/ha, regardless of year. Oxadiazon can be safely used as a PRE option when bermudagrass is recovering from SDS, while the use of oryzalin, prodiamine, dithiopyr, dimethenamid, pendimethalin, and indaziflam may limit recovery and further contribute to a weakened turfgrass system.

Organic fertilizers have increased in popularity over the past ten years due to the belief they are more environmentally sound to use than synthetic fertilizers. Most fertilizers derived from organic materials contain phosphorus as well as nitrogen, so use may be affected in states that legislate the application of P to lawns. States are considering exempting organic fertilizers from their zero-P legislation, as Wisconsin did, because it is thought that P from organic sources is less likely to be lost in leachate or runoff. Fertilizers are applied on turfgrasses as needed based on N form and content. Many organic fertilizers contain as much P as N in their formulations, and therefore similar amounts of P and N are applied with each application. Soil tests in native soil and a fairway sand and peat mix used in the Pacific Northwest showed that organic fertilizers applied at rates to provide adequate N for acceptable turf increased soil Bray-1 P levels from 16 to 18 mg/kg to 23 to 66 mg/kg within 3 years. Oxalate extractable Fe, Al, and P was determined for all treatments in both soils and used to calculate phosphorus saturation (PSI_ox). PSI_ox values from sand treated with one organic fertilizer source were significantly higher than measured in other treatments, indicating future risk of P loss with repeated applications of this organic fertilizer.

Salinity and waterlogging are two major abiotic stressors commonly associated with irrigated soils. In this experiment, tall fescue cv. Stonewall, Kentucky bluegrass cv. Bewitched, blue grama ecotype Bad River, and buffalograss cv. Texoka were germinated under well-drained (control), waterlogging (i.e., flooding), saline (5 g NaCl/liter), or a combination of waterlogging and saline conditions (saline-waterlogging) in two greenhouses (Study I and II). Plants were evaluated on germination percentage, shoot and root fresh weight, and the longest root length. Waterlogging with tap water did not inhibit seed germination or seedling growth. Germination, shoot and root fresh weight, and the longest root length were significantly decreased under saline conditions, alone or combined with waterlogging. The highest reduction occurred under saline condition alone which ranged from 36% of the control in the longest root length in Study I to 1% of the control in root fresh weight in Study II. Soil salinity levels were similar between the control and waterlogging treatments, which was significantly lower than the salinity treatment and the combined effects. Tall fescue was the most tolerant to both salinity and waterlogging stresses. Kentucky bluegrass, blue grama, and buffalograss showed a similar level of tolerance to salinity, waterlogging, and the combined stress.