Screening bermudagrass genotypes for improved forage production

Abstract Cynodon is a diverse genus of great economic importance to the southeastern United States. However, the bermudagrass stem maggot (BSM; Atherigona reversura Villeneuve) is threatening bermudagrass ( Cynodon spp.) throughout the region. Long‐term solutions require the development and release of BSM‐tolerant bermudagrass genotypes. The objective was to screen 15 experimental Cynodon genotypes for forage production characteristics and to determine their potential use as breeding lines for improved hybrid bermudagrass releases. Fifteen experimental genotypes and 5 cultivars (entries) with known variation in BSM tolerance were evaluated for forage production characteristics including seasonal digestible dry matter (DDM). Entry and insecticide strategy did not interact in any evaluation ( p > .13). Therefore, means for within year and insecticide strategy were compared using Dunnett's procedure to evaluate improvements in forage production beyond those reported for ‘Tifton 85’. Three entries produced seasonal DDM similar to Tifton 85 across all three seasons when sprayed with insecticide ( p < .01). These included 281, 287, and 308. Five entries consistently produced seasonal DDM similar to or greater than that of Tifton 85 across all three seasons when not treated with insecticide ( p < .01). These included 275, 281, 282, 287, and 308. Four entries—281, 282, 287, and 308—were determined to merit further investigation based on their consistent production capabilities under both insecticide strategies. All four entries were experimental genotypes selected from the USDA‐ARS Core Collection in Tifton, GA. These selections will be used in further evaluations of cold tolerance and longevity in the lower transition zone of the United States.