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Limited information exists regarding the optimum nitrogen (N) rates, source, and application frequency on bermudagrass (Cynodon spp.) establishment. Riviera bermudagrass was planted at 1.0 lb PLS and Patriot bermudagrass was planted at 8-10 live sprigs (3-6” long) per square foot on 1 and 3 July, 2008. Following planting, the entire area was covered with a spun-bonded geotextile fabric and irrigated regularly to keep the sand surface moist and promote seed germination and sprig establishment. Following seedling emergence, 12 days after planting (DAP), the covers were removed. Fertilizer treatments were initiated either at planting or shortly after seedling emergence. Turfgrass establishment was measured using visual ratings and also quantified using digital image techniques (two photos per plot) and analyzing for percentage green with SigmaScan software. All treatments were applied to 4x6 ft plots arranged in a randomized complete block design with three replications for all treatments. This study was initiated to develop best fertilizer programs that optimize Riviera’ bermudagrass seedling establishment and ‘Patriot’ bermudagrass sprig establishment on a sand-based rootzone during the summer months using different N rates, application frequencies, and granular and liquid N sources.

‘Riviera’ Bermudagrass - Visual turf cover ratings were initiated 16 days after planting (16 DAP) and, in general, Milorganite applied every 21 days at 1 lb N/M + TSP produced the fastest and best establishment. Interestingly, turfgrass treated with Green Spec 7-7-7 applied every 10 days at 0.5 lb N/M was faster to establish than Green Spec applied every 21 days at 1 lb N/M and performed equal to the Milorganite applied every 10 days at 0.5 lb N/M (Figure 1). By 72 DAP both Milorganite treatments and the Green Spec 7-7-7 treatment applied every 10 days at 0.5 lb N/M reached >90% turf cover. Green Spec applied once 14 DAP followed by a foliar fertilizer program did not achieve adequate turf establishment, likely as a result of too little N being applied (Figure 1). The percent (%) green using digital imaging produced results consistent with the visual ratings.

‘Patriot’ Bermudagrass - Visual turf cover ratings were initiated 16 days after planting (16 DAP) and, in general, turfgrass treated with Milorganite + TSP at 1 lb N/M and 0.5 lbs N/M respectively, and applied either 10 or 21 days produced the fastest establishment. Turf treated with 0.5 lb N/M of Green Spec 7-7-7 every 10 days produced consistent results and on 4 of 9 rating dates produced turfgrass establishment rates similar to both Milorganite + TSP treatments. Similar to ‘Riviera’ bermudagrass and unexpectedly, turfgrass treated with Green Spec 7-7-7 applied every 10 days at 0.5 lb N/M was faster to establish than Green Spec applied every 21 days at 1 lb N/M (Figure 2). By 72 DAP both Milorganite treatments and the Green Spec 7-7-7 treatment applied every 10 days at 0.5 lb N/M reached >94% turf cover. Similar to ‘Riviera’, Green Spec applied once 14 DAP, followed by a foliar fertilizer program did not achieve adequate turf establishment, likely as a result of too little N being applied (Figure 2). The percent (%) green using digital imaging produced results consistent with the visual ratings.

Importantly, the summer weather pattern was unusually cool and overcast compared to normal years with air temperatures during July rarely reaching or exceeding 85 F. This inevitably slowed seed and sprig development. In general, 3.5 lbs N applied over a period of 72 days with granular fertilizers including Milorganite + TSP and Green Spec 7-7-7 produced the best bermudagrass establishment. Applying 1 lb N/M of a granular fertilizer only once followed by foliar fertilizers was not enough N to effectively establish ‘Patriot’ or ‘Riviera’ bermudagrass. These results indicate that when using Green Spec 7-7-7 for bermudagrass establishment, the best results are achieved using a lower N rate (0.5 lbs/M) and shorter application interval (10 days).

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