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Sand Topdressing Rate and Interval Effects on Anthracnose Severity of an Annual Bluegrass Putting Green
Author(s) -
Inguagiato John C.,
Murphy James A.,
Clarke Bruce B.
Publication year - 2012
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/cropsci2011.01.0010
Subject(s) - biology , fungicide , horticulture , agronomy
Sand topdressing has been reputed to increase anthracnose caused by Colletotrichum cereale Manns sensu lato Crouch, Clarke, and Hillman on annual bluegrass (ABG) [ Poa annua L. forma reptans (Hausskn.) T. Koyama] putting greens. Field trials were conducted to determine the effects of (i) frequent (7 d) and low‐rate (0.3 L m −2 ) sand topdressing and brushing, (ii) infrequent (21 and 42 d) and increased‐rate (1.2 L m −2 ) sand topdressing, and (iii) sand topdressing application intervals (7, 14, and 28 d) and rates (0.3 and 0.6 L m −2 ) on anthracnose severity of ABG turf mowed at 3.2 mm. Topdressing every 7 d at 0.3 L m −2 initially enhanced disease (8%) during the first year of the trial; however, continued topdressing reduced anthracnose severity 17 to 47% later in 2006 and 3 to 26% in 2007 compared to nontopdressed turf. Topdressing every 21 and 42 d at 1.2 L m −2 reduced disease 4 to 28% over the 2‐yr study; however, sand applied every 21 d reduced disease 5 to 13% more than the 42‐d interval in 2007. Topdressing rate (0, 0.3, and 0.6 L m −2 ) and interval (7, 14, and 28 d) interacted to affect anthracnose severity in both years. Disease declined in a curvilinear manner as rate increased at the 7‐ and 14‐d intervals each year. Increased rates applied every 28 d reduced disease linearly in 2006 and curvilinearly at rates exceeding 0.3 L m −2 in 2007. Topdressing every 7 or 14 d at 0.3 or 0.6 L m −2 , respectively, provided the most rapid and effective anthracnose reduction and best turf quality.