Kennelly M.M.,Kansas State University |
Todd T.C.,Kansas State University |
Settle D.M.,Chicago District Golf Association |
Fry J.D.,Kansas State University
HortScience | Year: 2010
Moss is common on creeping bentgrass (Agrostis stolonifera L.) putting greens, and more control options are needed. Spot treatment of sodium bicarbonate (44.2 g L-1) was compared with broadcast sprays of carfentrazone-ethyl (50.5 or 101 g a.i./ha), chlorothalonil (8.2 or 12.8 kg a.i./ha) and a tank mixture of chlorothalonil, mancozeb, and thiram (8.2, 9.8, and 11.5 kg a.i./ha) in 2006 in Lemont, IL. Sodium bicarbonate suppressed moss growth equally as the conventional products. These results led to further experiments in 2008 in which moss suppression was evaluated within standard and alternative putting green management regimes in Manhattan, KS, and Lemont, IL. The standard approach included spring and fall applications of carfentrazone-ethyl (101 g a.i./ha) for moss control, biweekly applications of urea (46N-0P-0K) at 15 kg N/ha, and applications of chlorothalonil (8.2 kg a.i./ha) on a 14-day interval. Conversely, the alternative approach included spring and fall spot treatments of sodium bicarbonate (44.2 g L-1) for moss control, biweekly applications of a natural organic fertilizer (8N-1P-3K) to provide nitrogen at 15 kg N/ha, and applications of chlorothalonil (8.2 kg a.i./ ha) only when dollar spot reached a predetermined threshold level. Standard and alternative regimes were compared at both 3.2- and 4.0-mm mowing heights; synthetic and organic fertilizers applied alone without pest control approaches were included as controls. In Kansas and Illinois, moss coverage using the alternative management regime was not significantly different from that on greens managed using the standard regime. In Kansas, moss severity at a 3.2 mm was 1.6-fold higher than at the 4.0-mm height. In Illinois, sodium bicarbonate suppressed moss equivalently to the carfentrazone-ethyl treatment, and in the fertilizer-only controls, mowing at 3.2 versus 4.0 mm led to more moss coverage. These studies demonstrate that moss can be effectively suppressed on greens using spot applications of sodium bicarbonate and reduced moss encroachment is possible with higher mowing heights.
Nangle E.J.,Chicago District Golf Association |
Gardner D.S.,Dep. of Horticulture and Crop Science |
Metzger J.D.,Dep. of Horticulture and Crop Science |
Rodriguez-Saona L.,Dep. of Food Science and Technology |
And 3 more authors.
Agronomy Journal | Year: 2015
Pigments and phenolics that absorb ultraviolet light (UV) are involved in the protection of the photosynthetic apparatus during periods of high ultraviolet-B (UV-B) radiation and can be of benefit to turfgrasses. This study initiated in October 2010 and repeated in March 2011 aimed to characterize protective pigment responses to elevated UV-B in cool-season turfgrass. Tall fescue (Festuca arundinacea Schreb.), perennial ryegrass (Lolium perenne L.), and creeping bentgrass (Agrostis stolonifera L.) cultivars L93 and Penncross were tested. Turfgrass pigment responses were measured over a 1-wk period during which they were subjected to 16 kJ m-2 d-1 of UV-B in growth chambers. Photoperiod was 14 h and plants were subjected to 26.2 mol m-2 d-1 photosynthetically active radiation (PAR) at 20º C day and 17°C night. Turfgrass samples were collected at Day 0, 1, 3, 5, and 7. Measurements included chlorophyll uorescence, chlorophyll pigmentation, and avonoid, phenolic, anthocyanins, and carot-enoid concentrations. Chlorophyll uorescence increased and chlorophyll quantities decreased signi cantly (P < 0.05) in UV-B conditions compared to control. All species had signi cantly (P < 0.05) higher quantities of total phenolics and avonoids at the top of the tissue canopy relative to roots and shoot tissue near the soil surface. Anthocyanins were only found in creeping bentgrass L93. Carotenoids, zeaxanthin, and β-carotene declined in the UV-B treatment for both creeping bentgrass L-93 and Penncross a er 7 d, but did not decrease for perennial ryegrass or tall fescue. Carotenoids may play a greater role in UV-B tolerance than anthocyanins in cool-season turfgrasses due to their ubiquitous presence. © 2015 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved.