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The production of RAPD markers is rapid and provides a reliable mechanism for generating an almost infinite number of polymorphisms useful in cultivar identification. The potential use of RAPD markers to identify bulk seed samples of 13 synthetic creeping bentgrass (Agrostis stolonifera L. var. stolonifera) cultivars was examined. Two seed lots were evaluated for five of the 13 cultivars. Eight of the 50 oligonucleotide primers screened produced unique polymorphic amplification fragments that identified 11 of the 13 cultivars. Two cultivars could not be identified because the amplification fragments that distinguished one seed lot were not present in the second seed lot of the same cultivar. These observed differences among seed lots were repeatable. The results demonstrate that RAPD markers have the potential to be a valuable tool for the identification of synthetic turfgrass cultivars as long as precautions are taken to account for the possibility of seed lot effect.

Dollar spot (Sclerotinia homoeocarpa F.T. Bennett) is a widely distributed and destructive pathogen of turfgrass in the United States. A 2‐yr field study was conducted at Columbus, OH, to determine the influence of a plant growth regulator, creeping bentgrass (Agrostis stolonifera L.) cultivars, and N fertility on dollar spot severity. ‘Crenshaw’ creeping bentgrass was seeded alone or in a 50:50 blend by weight with ‘Penncross’ creeping bentgrass. Plots were fertilized at 0, 24.4, or 48.8 kg N ha−1 per application. One‐half of each plot received trinexapac‐ethyl (TE) [4‐(cyclopropyl‐α‐hydroxymethylene)‐3,5‐dioxo‐cyclohexanecarboxylic acid methyl ester] at 0.8 L ha−1. The TE and fertilizer treatments were initiated in May 1995 and 1996 with four subsequent applications made at 30‐d intervals. Initially, the cultivar blend reduced the rate of dollar spot development compared with Crenshaw alone; however, neither the blend nor Crenshaw provided commercially acceptable dollar spot suppression throughout the study. Both TE and N fertilization significantly (P ≤ 0.05) reduced dollar spot severity over the 2‐yr period. Trinexapacethyl applied alone effectively suppressed dollar spot activity, but efficacy increased with increasing N rates. Dollar spot symptoms decreased and thatch thickness increased at elevated N levels. During this 2‐yr study, interactions between TE and N fertility resulted in a significant (P ≤ 0.05) reduction in dollar spot severity. Thus, on golf course fairways where dollar spot may be severe, incorporation of these two treatments into a turfgrass management program will enhance dollar spot suppression and reduce fungicide inputs.

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.

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