Nitrogen Source and Rate Effects on the Establishment of 'TifSport' and 'Tifway' Hybrid Bermudagrass

摘要

In the southeast United States, the most popular vegetatively propagated hybrid bermudagrass (Cynodon dactylon x C. transvaalensis Pers. L.) has long been the cultivar Tifway. In recent years, however, southern turf managers choosing cultivars for lawns, golf course fairways, or athletic fields have a newer option: 'TifSport' hybrid bermudagrass, also a vegetative selection. Although the use of TifSport is increasing, research that studies the establishment of TifSport is largely absent from the literature, as most past work has focused exclusively on Tifway. Thus, the objective of our research was to evaluate the establishment of Tifway and TifSport hybrid bermudagrasses when established from sprigs, examining the effect of N rate and N source of the rate of groundcover, shoot density, and stolon and rhizome development. The study was conducted in 2002 and 2004; in each year, new plots were fumigated and then sprigged with Tifway and TifSport. Nitrogen source treatments were ammonium nitrate (AN) (34-0-0) or calcium (Ca) nitrate (CaN) (16-0-0; 39% Ca), both applied at 2.4, 4.9, 7.3, or 9.8 g N m-2 wk-1. Treatments were a factorial combination of cultivar, N rate, and N source. Collected data included percentage groundcover as measured via line-transect, shoot density, and dry weight of stolons and rhizomes. In both years, TifSport had higher percentage groundcover than Tifway at early measurement dates, with >95% groundcover for both cultivars at 7 and 5 weeks after sprigging for 2002 and 2004, respectively. Shoot density often increased as N rate increased, with shoot density maximized at N rates between 6.2 and 7.6 g N m-2 wk-1. In both years, dry weight of stolons and rhizomes decreased as N rate increased.