| Abstract/Contents: | "This study was undertaken to determine the product effectiveness of one registered insecticides to suppress first generation annual bluegrass weevil (ABW) on a public golf course fairway adjacent to the rough in Lewisburg. The turfgrass area consisted of annual bluegrass (75%) and perennial ryegrass (25%). Treatment plots were 7 Œ 4 ft, arranged in a RCB design and replicated three times with a 1 ft barrier around all replicates. Liquid formulations were applied by using a CO2 sprayer with four 8002VS TeeJet nozzles mounted on a 7 ft boom, operating at 32 psi, and applied in 212 ml of water/28 ft2 or delivering 2.0 gal/1000 ft2. At treatment time one (22 Apr; 100 GDD) the following soil and environmental conditions existed: air temp, 63 °F; soil temp at l inch depth, 52 °F; soil temp at 2 inch depth, 50 °F; RH, 58%; amt of thatch, 0.75 inch; water pH, 7.0; application time, late morning; soil, wet; thatch, wet; and clear skies. Forsythia's foliage was 50% gold and 50% green. General soil conditions were as follows: soil textural class, loam; soil particle size analysis: sand, 43.1%; silt, 42.8%; clay, 14.1%; soil percent water content (percent by wt), 21.2; organic matter, 3.5%; CEC, 12.3; and soil pH, 5.4. The area was irrigated in immediately after treatment with 0.1 inch of water. At treatment time two (13 May; 241 GDD) the following soil and environmental conditions existed: air temp, 70 °F; soil temp at l inch depth, 50 °F; soil temp at 2 inch depth, 50 °F; RH, 31%; amt of thatch, 0.75 inch; water pH, 7.0; application time, late morning; soil, moist; thatch, moist; and clear skies. Forsythia foliage was 100% green. General soil conditions were as follows: soil textural class, loam; soil particle size analysis: sand, 44.0%; silt, 43.3%; clay, 12.6%; soil percent water content (percent by wt), 23.5; organic matter, 4.0%; CEC, 15.6; and soil pH, 5.3. The area was irrigated in immediately after treatment with 0.1 inch of water. At treatment time three (22 May; 271 GDD) the following soil and environmental conditions existed: air temp, 53 °F; soil temp at l inch depth, 48 °F; soil temp at 2 inch depth, 50 °F; RH, 64%; amt of thatch, 0.75 inch; water pH, 7.0; application time, late morning; soil, wet; thatch, wet; and cloudy skies. General soil conditions were as follows: soil textural class, loam; soil particle size analysis: sand, 43.6%; silt, 42.4%; clay, 14.0%; soil percent water content (percent by wt), 23.1; organic matter, 3.5%; CEC, 15.5; and soil pH, 5.2. The area was irrigated in immediately after treatment with 0.1 inch of water. Forsythia foliage was 100% green. At treatment time four (2 Jun; 408 GDD) the following soil and environmental conditions existed: air temp, 75 °F; soil temp at l inch depth, 62 °F; soil temp at 2 inch depth, 60 °F; RH, 35%; amt of thatch, 0.75 inch; water pH, 7.0; application time, mid morning; soil, moist; thatch, moist; and clear skies. The area was irrigated in immediately after treatment with 0.1 inch of water. General soil conditions were as follows: soil textural class, loam; soil particle size analysis: sand, 42.6%; silt, 43.6%; clay, 13.7%; soil percent water content (percent by wt), 12.6; organic matter, 4.3 %; CEC, 15.4; and soil pH, 5.3. Two 4 inch cup cutter sod samples were removed from each replicate on 10 Jun. The total no. of ABW teneral adults, pupae and larvae was recorded and converted to ft2. Data were analyzed with ANOVA and the mean separation test used was WD. The area selected for the experiment had been infested with a natural population of ABW during 2007 and 2008. The first ABW larvae were collected on 28 May. The breakdown of ABW larval life stages only removed from three untreated checks follows: 20.2% first- second instars, 47.8%; third, fourth and fifth instars; pupae, 27.5%; and teneral adults, 4.3%. Four treatments provided significant suppression of ABW. No phytotoxicity was noted." |
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