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Grazing Termination Date Influence on Annual Ryegrass Seed Production and Reseeding in the Southeastern USA
Author(s) -
Evers Gerald W.,
Nelson Lloyd R.
Publication year - 2000
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2000.4061724x
Subject(s) - biology , cultivar , seedling , lolium multiflorum , agronomy , grazing , dormancy , growing season , dry weight , yield (engineering) , horticulture , germination , materials science , metallurgy
Production costs could be reduced if annual ryegrass ( Lolium multiflorum Lam.) could be managed for reseeding. Spring grazing termination dates (GTD) of 31 March, 14 April, 28 April, and 12 May were evaluated on seven cultivars for two growing seasons to study spring seed production and volunteer reseeding the following autumn in northeast Texas. There were year × GTD × cultivar interactions for spike density, seed yield, seed weight per spike, and volunteer seedling density and a year × GTD interaction for 1000‐seed weight. Moisture conditions were good during the 1994‐1995 growing season followed by a dry summer. Spike density was high (1256 ± 59 spikes m −2 ), seed yields were low (48.7 ± 3.2 g m −2 ), but seed weight was high with a 1000‐seed weight of 3.12 ± 0.03 mg. All cultivars exceeded the 500 seedlings m −2 target in 1995 when grazed through 28 April. In the 1996‐1997 growing season, May was very dry followed by high June rainfall. Spike density was lower but seed yields were higher than in 1995. However, 1000‐seed weight was only 1.37 mg. Only `Surrey' exceeded 500 seedlings m −2 through 28 April GTD, `TAM 90' through 14 April GTD, and `Rio', `Gulf', and `Jackson' at only one of the two early GTDs. The superior reseeding ability of Surrey is probably due to its selection for a high level of high temperature dormancy. In normal rainfall years in the southeastern USA, most cultivars of annual ryegrass can be grazed until late April and still produce satisfactory volunteer stands the following autumn.