Posttreatment Irrigation Research Articles

Influence of Application Dates on the Efficacy of Rh-0345101 for Control of an Induced Japanese Beetle Larval Population in Turfgrass, Wayne County, Ohio, 1995

Abstract The study was located on the lawns of the Ohio Agri-cultural Research and Development Center at Wooster, Ohio. Applications were made 10 May, 3 Jul, and 14 Aug to plots 3 X 5 ft (0.9 X 1.5 m) arranged in a RCB replicated 4 times. Treatments were applied with a CO2 sprayer and Teejer™ XR8010VS nozzles at 30 psi (2.19 kg/cm2) pressure that delivered a volume of 3.1 gal/1000 ft2 (1262 liter/ha). Each plot received 4.5 gal (17 liters), approximately equal to Y2 ½ inch (13 mm) posttreatment irrigation, of water using a sprinkling can. The site conditions were: 100% Kentucky bluegrass, 0-¼inch (0-6 mm) loose thatch, level. Environmental conditions at the 10 May treatments were as follows: JB larvae: none present; Turf: dry, 2% inch (5.7 cm) ht; Soil: moist, 60°F at 1 inch (2.5 cm) and 58°F at 3 inch (7.6 cm); Weather: partly cloudy, 68°F, 3-12 mph wind. Environmental conditions at the 3 Jul treatments were as follows: JB larvae: none present; Turf: dry, 2.5 inch (6.4 cm) ht; Soil: moist, 64°F at 1 inch (2.5 cm) and 3 inch (7.6 cm) depth; Weather: sunny, 67°F, 3-15 mph wind. Environmental conditions at the 14 Aug treatments were as follows: JB larvae: 1st instars present; Turf: dry, 2.25 inch (5.7 cm) ht; Soil: slightly moist, 91°F at 1 inch (2.5 cm) and 86°F at 3 inch (7.6 cm) depth; Weather: sunny, 90°F, 0-12 mph wind. A caging technique was used to insure JB oviposition into the plots. Three cylinders 8 inch (20.3 cm) in diam by 6 inch (15.3 cm) ht were inserted into the plots 19 Jul. Thirty JB adults (>50% 9) were confined in each cylinder, and fed fresh apple slices coated with brewers yeast every 2 days for 14 days. Cylinders were then removed. Efficacy data taken 26 Sep (139, 77, & 43 DAT) were based on the number of live larvae in three samples 12X12 inch (30.5 X 30.5 cm) centered over the caging locations in each plot. Analysis of variance was done on plot totals and means separated by LSD test at P = 0.05.

Control of Japanese Beetle and Northern Masked Chafer Larvae on a Golf Course Rough in Summit County, OHIO, 1995

Abstract The study was located on a golf course rough at Akron, Ohio. Insecticides were applied 24 Aug to plots 8 X 10 ft (2.4 X 3.1 m) arranged in a RCB replicated 4 times. Granular materials were applied using a drop spreader. All liquids were applied with a CO2 sprayer and TeeJet™ 8015 nozzles at 60 psi (4.22 kg/cm2) pressure that delivered a volume of 3 gal/1000 ft2 (1222 liter/ha). The entire experimental area received ½inch of posttreatment irrigation using the golf course system. Environmental conditions at time of treatment were as follows: JB: approximately 12/ ft; 20% 1", 70% 2nd, 10% 3rd instars; NMC approximately 8/ft2; 20% 2nd, 80% 3rd instars; Turf: level, dry, 2.25 inch (5.7 cm) ht, 50% Kentucky bluegrass, 25% annual bluegrass, 25% bentgrass, No thatch; Soil: moist, 72°F at 1 inch (2.5 cm) and 72°F at 3 inch (7.6 cm); Weather: sunny, 75°F, 0-2 mph (0-3 km/h). Efficacy data taken 27 Sep (30 DAT) were based on the number of live, in six 7 X 7 inch (17.8 X 17.8 cm) square samples from each plot.

Pendimethalin Efficacy and Dissipation in Turfgrass as Influenced by Rainfall Incorporation

A 2-yr field study was conducted to determine effects of posttreatment irrigation timing on pendimethalin efficacy and dissipation in turfgrass. Factors investigated included herbicide rate, formulation, and the interval between pendimethalin application and the initial posttreatment irrigation. Plots received an initial posttreatment irrigation of 1.25 cm 0, 7, 14, 21, and 28 d after treatment. Pendimethalin efficacy on smooth crabgrass was evaluated, and turfgrass foliage and the upper 2.5-cm layer of soil were periodically assayed for pendimethalin residues. Pendimethalin 1.71% granular provided better weed control than pendimethalin 60% wettable powder at all rates, irrigation events, and years. Efficacy of granular pendimethalin was not affected by a delay in posttreatment irrigation, whereas efficacy of pendimethalin in the wettable powder formulation was reduced when irrigation was applied later than the day of treatment. Chromatographic analyses indicated that an average of 54% of the applied pendimethalin (wettable powder formulation) was retained on turfgrass foliage immediately after treatment, compared to 9% for the granular formulation. Soil residue analyses confirmed that a greater proportion of applied pendimethalin reached the soil surface immediately after treatment in the granular formulation than in the wettable power formulation.

Control of Black Cutworm with Tempo, 1993

Abstract Two formulations and two rates of Tempo were treated against the black cutworm on a golf course green. Plot size was 3 ft2 with 3 ft buffers between plots. Plots were arranged in an RCB design with 4 replications. Black cutworms were 75% 3rd instar and 25% 4th instar at the time of treatment. Treatments were applied with a CO2 backpack sprayer at a volume of 1 gal/ 1000 ft2. Treatments were applied on 8 Sep and rated 11 Sep. The trial was rated by soaking each plot with soap solution (1 oz. Joy detergent/1 gal water) and counting the emerging larvae. Conditions at the time of treatment were: air temperature, 65°F; soil temperature, 68°F; thatch depth, 0.5 inch; soil texture, sandy loam; post treatment irrigation, 0.

Black Cutworm Control on Golf Course Greens with Bacillus Thuringiensis and Fenoxycarb, 1993

Abstract Treatments were duplicated on greens at two golf courses. Plots were arranged in a RCB design, replicated 4 times. Plot size was 8 × 8 ft. Liquids were applied in 2 liters of water with a sprinkler can. Trial 1 (Buckhannon C.C.) was initiated 20 Aug. Plots were not pre-irrigated because the green was wet from overnight rain and treatments were applied during a light rain; about 0.02 inches of rain occurred shortly after all treatments were applied and there was no posttreatment irrigation. Environmental conditions were: air temperature, 23°C; RH, 97%; overcast with light rain; soil temperatures, 23°C (1 inch), 25°C (surface). Treatments were evaluated at 6 DAT by treating the entire green with cyftuthrin (Tempo) at 0.04 lb (AI)/acre and counting the no. of larvae flushed to the surface after about 1 h. Larvae were mostly small to medium in size ranging from 5 to 36 mm in length with 92% being less than 20 mm long. Trial 2 (Clarksburg C.C.) was initiated 23 Aug. Plots were pre-irrigated with 2 liters of water per plot, treatments were applied, then irrigated with 2 liters about 40 minutes posttreatment. Environmental conditions were: air temperature, 26.5°C; RH, 57%; clear and calm; soil temperature, 23.5°C (1 inch), 28°C (surface). Treatments were evaluated at 7 DAT using the same method as in Trail 1. Larvae were mostly small to medium in size ranging from 5 to 43 mm in length with 72% being less than 20 mm long.

Control of Japanese Beetle and Northern Masked Chafer Larvae on a Golf Course Fairway, 1993

Abstract The study was located on a golf course fairway at Carrollton, Carroll county, OH. Insecticides were applied 24 Aug to plots 8 × 10 ft (2.4 × 3.1 m) arranged in a RCB, replicated 4 times. Granular materials were applied using a drop spreader. All liquids were applied with a CO2 sprayer with Teejet XR8006VS nozzles at 35 psi (2.46 kg/cm2) pressure that delivered a volume of 1 gal/1000 ft2 (407 liter/ha). Before the entire experimental area was irrigated approximately lA inch (6 mm) of water using the golf course system, plastic sheets 12 × 12 ft (3.6 × 3.6 m), were laid over one of the Orthene treatments in each replicate so they received no posttreatment irrigation. Environmental conditions at time of treatment were as follows. JB: ca. 270/m2, 15% 1st, 70% 2nd, 15% 3rd instars. Turf: level, dry, 1.5 inch (3.8 cm) height, 100% Kentucky bluegrass. Thatch: dense, moist, 0-VA inch (0-6 mm). Soil: moist, 80°F at 1 inch (2.5 cm) and 77°F at 3 inch (7.6 cm). Weather: sunny, 82°F, 2-10 mph (4-16 km/h). Water: pH 4.6. At the time of data acquisition a disease was found to have recently infected >30% of the JB larvae throughout the study area. Diseased grubs were collected for identification of the pathogen and further study of it. Efficacy data taken 5 Oct (41 DAT) were based on the number of live, sick, and freshly dead (appx 90% JB: 10% NMC) in six 7 × 7 inch (17.8 × 17.8 cm) square samples from each plot. No phytotoxicity was observed.

Control of Billbug Larvae and a Subsequent White Grub Population on a Lawn Area in Wayne County, Ohio, 1993

Abstract The study was located lawns of the Agricultural Technical Institute at Wooster, Ohio. Insecticides were applied 15 Jun to plots 10 x 10 ft arranged in a randomized complete block, replicated 4 times. Granular insecticides were applied using a drop spreader and liquids using a CO2 sprayer with Teejet 8010LP nozzles at 30 psi that delivered a volume of 3 gal/1000 ft2. The experimental area received no posttreatment irrigation. Environmental conditions at time of treatment were as follows. Billbugs: early instars present, no pretreatment count. Turf: 3° slope, dry, 3 in height, 50% Kentucky bluegrass, 50% perennial ryegrass. Thatch: moist, Vi inch, dense. Soil: moist, 68°F at 1 inch and 55°F at 3 inches. Weather: sunny, 73°F, 5-8 mph. Water: pH 4.9. Billbug efficacy data taken from each plot 9 Jul (28 DAT) were based on the number of live billbug larvae and pupae in 6, AVi inches in diam samples from each plot. Efficacy data for control of a subsequent JB and NMC larval population (appx 70% JB: 30% NMC) taken 5 & 7 Oct was based on the number of live grubs in 6, 7 × 7 in samples from each plot.

Control of the Billbug Adults on A Lawn Area in Wayne County, 1992

Abstract The study was located on lawns of the Ohio Agricultural Research and Development Center at Wooster, Ohio. Insecticides were applied 22 Apr to plots 12.2 X 12.2 m arranged in RCB replicated 4 times. Granular insecticides were applied using a drop spreader and liquids using a CO2 sprayer with Teejet 8015 nozzles at 3.87 kg/cm2 pressure that delivered a volume of 1384 liter/ha. The experimental area received no posttreatment irrigation. Environmental conditions at time of treatment were: billbugs: overwintered adults active; turf: level, dry, 6.35 cm height, 75% Kentucky bluegrass, 15% Tall fescue, 10% broadleaf weeds; thatch: none; soil: moist, 58°F at 2.54 cm and 55°F at 7.62 cm; Weather: cloudy, 57°F, 5-16 km/h; water: pH 6.75. Efficacy data taken from the center 9.3 m2 of each plot Jul (78 DAT) were based on the number of live billbug larvae and pupae in 8, 10.8 cm diam samples from each plot.

Soil Ph and Irrigation Effects on Residual Control of White Grubs with Triumph 4 E, 1991

Abstract This study was conducted in a Kentucky bluegrass plot at the Univeristy of Kentucky Spindletop Research Farm, Fayette Co., KY. The established turf was on a Maury silt loam soil (fine-silty, mixed, mesic Typic Paleudalf), with pH = 5.8. Thatch accumulation was <0.25 inch. Experimental plots for separate tests of residual effectiveness of isazophos (Triumph 4 E) as affected by irrigation and soil pH were established in late Jun. A split-plot design with 5 replications was used for each test. For the irrigation test, there were two levels of watering (3" total per wk in two watering periods, or natural rainfall). Main plots (6 × 5 ft) were divided into two subplots (3 × 5 ft) maintained under the different irrigation regimes. For the pH test, each main plot (9 × 5 ft) was divided into three subplots (3 X 5 ft). Subplots were treated either with ammonium sulfate to lower soil pH, calcium hydroxide to elevate soil pH, or were left untreated. Two applications of ammonium sulfate (0.9 lbs/15 ft2) were applied to acidic subplots on 3 Jul and 8 Jul. Calcium hydroxide (1.8 lbs/15 ft2) was applied to basic subplots on 3 Jul. Soil samples were taken from each-plot at the beginning (11 Jul) and end of the test (15 Sep) and analyzed for pH. On 19 Jul, we sunk five, 8 inch diam cylinders made from PVC sewer pipe into each subplot to 7.5 inch depth in both tests. Cylinders represented microplots which were either left untreated or treated with isazophos (Triumph 4 E) at 2 lbs AI/A. Non-watered microplots in the irrigation test were covered with aluminum foil before the rest of the site was irrigated. Treatments were applied 19 Jul, 2, 16 Aug, or 3 Sep, representing 6 wk, 4 wk, or 2 wk before grubs were present, or 3 Sep, after grubs were added (remedial treatment). Third instar JB were collected from an untreated golf course rough on 1 Sept, and 10 active grubs were placed in each cylinder. Grubs that had not burrowed into the turf within 10 min were replaced. Treatments were prepared by mixing 1.52 ml of isazophos in 1 liter of water, and applying 10 ml to each microplot using a trigger-type hand sprayer. Posttreatment irrigation (0.75 inch) was applied to all microplots immediately following isazophos treatments. The cylinders were harvested on 15 Sep. The soil was carefully examined in large plastic pans and the no. of surviving grubs was counted.

Black Cutworm Control on Golf Course Greens with An Entomogenous Nematode, 1990 and 1991

Abstract In 1990 treatment plots were 15 × 20 ft arranged in a randomized complete block design, replicated 4 times using 3 greens. Treatments were applied 9 Aug between 0800 and 0900 h while the grass was still moist; air temperature was 70-75"C at application time. Posttreatment irrigation was about 1/2 inch applied within about 1 h after treatments were applied. Larvae were mostly small to medium in size ranging from 8 to 34 mm in length with 88% less than 20 mm long. In 1991 experimental plots were 10 × 10 ft arranged in a randomized complete block design, replicated 5 times using 1 green. Treatments were applied 14 Aug in mid-morning. The green was moist after a heavy overnight rain. Environmental conditions were as follows: soil temperature, 20°C (1 inch), 20.5°C (surface); RH, 89%; overcast with heavy fog. Plots were not irrigated after treatments were applied. Larvae were mostly small ranging in size from 6 to 16 mm in length with 80% less than 14 mm long. In both years, applications were made with a CO2 sprayer operated at 30 psi; 2 liters of spray were used to apply the treatments. Treatments were evaluated at 7 DAT by treating the greens with Baythroid 2 E at 0.04 lb (AI)/acre and counting the number of larvae flushed to the surface in each plot.

Persistence and Mobility of Isazofos in Turfgrass Thatch and Soil

Isazofos was applied to turfgrass as an emulsifiable concentrate (480 g/liter) at 2.24 kg (AI)/ha. Irrigation regimes included application of 10.2 liters/m2 water immediately, and 8, 24, and 36 h after treatment. Persistence and movement of the insecticide was measured by gas chromatographic analyses of core samples of thatch, and first and second 2.5 cm of soil at 3 h, 3 d, and 1, 2, 4, 8, 36 wk after treatment. Green grass was removed and not analyzed. The thatch contained 96–99% of detectable residues recovered with a range of 0.123 (8 wk) to 3.57 ppm (3 h). Immediate posttreatment irrigation resulted in significantly higher residues in the thatch during the first 2 wk of sampling. Residues in the first and second 2.5 cm soil during the 8-wk sampling period ranged from 0.002 to 0.04, and 0.024 to < 0.001 ppm, respectively. At 36 wk, residues were ≤0.045 in the thatch, ≤0.003 in the first, and ≤0.001 ppm in the second 2.5 cm soil. Although useful in moving the insecticide off the grass blades and into the thatch, posttreatment irrigation had no significant effect on movement of the insecticide into the soil.

The Influence of Application Timing and Posttreatment Irrigation on the Fate and Effectiveness of Isofenphos for Control of Japanese Beetle (Coleoptera: Scarabaeidae) Larvae in Turfgrass

During 1984, isofenphos 1.5 and 5% granular and 2 flowable (2.24 kg [AI]/ha) applied 11 April to golf course turfgrass in Canal Fulton, Ohio, resulted in 92% average reduction of overwintered Japanese beetle, Popillia japonica Newman, larvae 48 dafter application. Of treatments applied April through August, only August applications significantly reduced summer larvae. Analysis by gas/liquid chromatography for isofenphos and oxyisofenphos residues in samples taken 6 August from the April, May, June, and July treatments showed that 79, 92, 94, and 97%isofenphos, respectively, remained in the thatch. Mean oxyisofenphos residues at this time were 54, 45, 54, and 63%, respectively, of total residue. Oxyisofenphos residues 5–6 d after the 11 April and 14 August applications were 7 and 15%, respectively, of the total. Immediate posttreatment irrigation, plus regular subsequent irrigation and rainfall, did not improve isofenphos penetration into the soil or enhance larva control.