Eco, Milorganite, Ringer, and Sustane natural organic fertilizers, alone or combined with the synthetic organic fertilizer isobutylidene diurea (IBDU), were compared with IBDU alone for their effect on a `Tifdwarf' hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] golf course putting green. Over the 2-year study period, no consistent differences were observed among the fertilizer treatments on the turfgrass growth parameters of quality, clipping weights, or root weights.
Abstract
Eight bermudagrass [Cynodon dactylon (L.) Pers. and related species] clonal selections were inoculated with a mixed sample of ectoparasitic nematodes and were grown for 5 months in 13-cm pots. Relative to control (noninoculated) pots, nematodes reduced root dry weight 13% (P < 0.01) but had no effect on overall shoot (clippings) yield. Commercially available cultivars ‘Tifgreen’ and ‘Tifdwarf’ had significantly greater root weight reductions and also supported significantly higher densities of the lance nematode, Hoplolaimus galeatus, than most other clones.
This study was conducted to determine rooting characteristics, root carbohydrate content, and performance of 10 bermudagrass [Cynodon dactylon (L.) Pers.] genotypes exposed to drought. A greenhouse study was conducted twice to determine root distribution and carbohydrate content throughout the soil profile during simulated drought stress. Root distribution among genotypes and accumulation of total nonstructural carbohydrate within roots differed with depths. Root mass at 30, 60, 90, and 150 cm was significantly correlated with turf quality during drought stress (r = 0.72, 0.86, 0.80, and 0.81, respectively) only for one of the two tests. Root carbohydrate distribution was not significantly correlated with turf quality for the selected bermudagrass genotypes.
Abstract
Electrolyte leakage and regrowth tests were used to estimate cold hardiness levels of field-grown ‘Midiron’ and ‘Tifgreen’ bermudagrass (Cynodon dactylon × C. transvaalensis crowns. The two procedures were in close agreement. ‘Midiron’ was hardier than ‘Tifgreen’ on all sampling dates. Greatest levels of freeze tolerance were –11°C for ‘Midiron’ and –7° for Tifgreen’ during December and January, ‘Midiron’ was killed at –5° in early June while ‘Tifgreen’ had lost all freeze tolerance by this date. Although the electrolyte leakage procedure was rapid and required no greenhouse space, it was relatively difficult to set up and evaluate.
Abstract
Postemergence applications of 1.1 and 0.6 kg/ha of sethoxydim (2-[l-ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-l-one) and fluazifop-butyl (butyl 2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]propionate), respectively, resulted in 90% control of common bermudagrass (Cynodon dactylon) when applied directly over field-grown ornamentals. Comparable control was achieved by either single application or 2, half-rate, split applications. Of the 12 species tested, only ‘Hexe’ azalea was damaged by applications of fluazifop-butyl to a degree that the plants were unsaleable. All other species exhibited tolerance to both sethoxydim and fluazifop-butyl at the rates required to achieve grass control.
Abstract
Methyl sulfanilylcarbamate (asulam) was effective for the selective control of several grassy weeds in established st. augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), ‘Tifway’ bermudagrass (Cynodon dactylon L.), and ‘Emerald’ zoysiagrass (Zoysia matrella Merr.). Bahiagrass (Paspalum notatum Flugge) and centipedegrass (Eremochloa ophuroides (Munro) Hack.) were severely injured when asulam was used at a rate of 2.24 kg ai/ha. Thirty-six species of ornamental plants were relatively tolerant to foliage applications of asulam at rates of 2.24 and 4.48 kg ai/ha with growth normal on all but 4 ornamental species 22 weeks following treatment.
Abstract
Three genetically diverse Kentucky bluegrasses (Poa pratensis L. cvs. Kenblue, Vantage, and Adelphi) and 6 other turfgrasses were evaluated for susceptibility to the greenbug, Schizaphis graminum Rondani. Nine common lawn weed species were also tested as potential alternative hosts. Heavy greenbug populations and feeding damage occurred on all 3 bluegrasses and on tall fescue (Festuca arundinacea Schreb. cv. Kentucky 31) and chewings fescue (Festuca rubra var. cummutata Guad. cv. Jamestown). Creeping bentgrass (Agrostis palustris Huds. cv. Penncross), bermudagrass (Cynodon dactylon L. cv. Midiron), perennial ryegrass (Lolium perenne L. cv. Derby), and zoysia grass (Zoysia japonica Steud. cv. Meyer) were not suitable hosts. No greenbugs survived on the 9 weed species tested.
Abstract
Root growth of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] and bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Davy] (C-4 plants), show distinct seasonal patterns different from those of the cool-season perennial grasses (C-3 plants). Root growth continued after winter shoot dormancy occurred, and at soil temperatures below 10°C. Severe browning of the entire root system was observed just after spring shoot greenup followed by a delay of about 3 weeks in new root initiation and replacement, even though significant shoot development was occurring prior to this period of root initiation.
A 2-year establishment study of perennial peanut (Arachis glabrata Benth.) planted in row middles of a 1-year-old citrus grove was initiated in southwest Florida. The effect of herbicide and fertilizer treatment combinations on perennial peanut density was measured. Treatments were Fluazifop-p-butyl (Fusilade 2000 1E) herbicide, K-Mag fertilizer, Fluazifop-p-butyl + K-Mag + N, and a nontreated control. Four replications were arranged in a randomized complete-block design. After 2 years, there were no significant differences in plant density between treatments (96% cover) and the control (89% cover). Applications of Fluazifop-p-butyl in years one and two were effective in controlling grassy weeds such as common bermudagrass [Cynodon dactylon (L.) Pers]. In this experiment. initiated 1 year after planting, perennial peanut without inputs (herbicide, fertilizer) was able to suppress common bermudagrass and to obtain a high level (89%) ground cover in 3 years (1991–94).
Field and laboratory studies were conducted to evaluate the K retention properties of several resin-coated (RC), sulfur-coated (SC), and plastic-coated (PC) K fertilizers. Substantial differences in K release were found among the controlled-release K materials, based both on the K content of `Tifgreen' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burt-Davvy] clippings and on direct measurement of K remaining in fertilizer granules in the field over time. One SC material appeared to release K too rapidly, and one RC material appeared to release K too slowly to be useful for providing extended plant-available K to turfgrass. The other sources appeared to have release characteristics that would be favorable for turfgrass maintenance. Because differences in K release were observed among the sources, a laboratory method for assessing K release would be useful. Toward this-end, models were developed relating K retention of sources in hot water (70C) to K retention under field conditions.