High Clearance Sprayer Research Articles

Control of Silverleaf Whitefly (Swf) on Tomato Using Sanmite Applied with Hydraulic and Airboom Sprayers, 1996

Abstract Tomato seedlings “Agriset” from a commercial plant house were transplanted on 7 Mar 96, 18 in between plants, into raised beds 32 in wide and 250 ft long on 6-ft centers. They were covered with black polyethylene film mulch. A dry bottom mix of 50 lbs N, 160 lbs P and 80 lbs K per acre was placed at the bottom of the beds and an additional 3.25 lbs per acre N and K was fertigated 3 times a week by drip irrigation. The plants were sprayed weekly with an alternating combination of Maneb 80 WP at 1.5 lb/acre plus Kocide 101 at 2 lb/acre and Bravo 720 at 2 pt/acre for disease control. Dipel was added to the disease control sprays when needed at a rate of 1 lb product/acre. Each of the 4 beds was used as a replication divided into 5 plots separated by 2-ft buffers, with each 48-ft plot randomly assigned to 5 treatments. Applications were initiated 16 May when whitefly population was established and continued weekly for 3 weeks. Spray was delivered using two different types of spray equipment: a high clearance sprayer utilizing an hydraulic pump operating at 200 psi, delivering spray through 6 Yellow Albuz hollow cone nozzles, 3 per drop boom at a volume of 69 gpa at 2.5 mph, and a Berthoud airboom sprayer delivering spray material at 50 psi through 6 Brown Albuz nozzles, atomized by an airblast 172 mph and dispensing at a volume of 35 gpa. Spray coverage was evaluated on 8 May by using water sensitive papers and spectophotmetric analysis of FD&C#1 blue dye deposited on paper targets. Plants were evaluated weekly for the presence of whitefly adults, eggs, nymphs, pupa and parasitized pupae on a trifoliate from the 6th node of 8 randomly selected plants per plot. Counts were made using stereoscopic microscope by placing a 1 cm sq template twice on each side of the midvein of each leaflet (4 cm2/leaflet = 12 cm2/trifoliate = 96 cm2 per plot). Adult whitefiies were evaluated by striking plants 5 times with a 9.5" X 13" pie pan painted black and covered with a 9:1 oil/detergent mixture (N = 6/plots). Fruit was not harvested for evaluation because a heavy infestation of pin worm and high incidence of disease on many of the plots would have rendered the data of little value.

Efficacy of Selected Insecticide Mixtures for Bollworm/Tobacco Budworm Control, 1996

Abstract Thirteen treatments (insecticides and mixtures) were evaluated at the Red River Research Station, Bossier City, LA, to determine their efficacy in controlling the BW/TBW complex on cotton. Plots were planted 3 May and were 4 rows X 100 ft on 40-inch centers. All plots had Temik 15G (0.5 lb [AI]/acre) applied m-furrow at planting. The experimental design was a RCB with 4 replications. Prior to trial initiation, plots were oversprayed for boll weevils on 4 Jun and 12 Jul (Vydate C-LV at 0.25 lb [AI]/acre); for BW/TBW on 14 Jun (Orthene 90SP at 1.0 lb [AI]/acre), 29 Jun and 18 Jul (Baythroid 2EC at 0.03 and 0.033 lb [AI]/acre, respectively); and for aphids on 29 Jun and 9 Jul with Lorsban 4EC at 0.5 lb [AI]/acre and Provado 1.6F at 0.047 lb [AI]/acre, respectively. Insecticide treatments were applied in 5.9 gpa at 60 psi with TX-3 hollow-cone nozzles spaced 20 inches apart (2 nozzles/row). Treatment were applied with a high-clearance sprayer equipped with a CO2 system for spraying small plots. Insecticide treatments were applied on 23, 30 Jul and 6 Aug. During and after the trial, all plots were oversprayed for boll weevils with methyl parathion 4EC at 0.33 lb [AI]/acre on 2, 19, 21, 30 Aug and 6 Sep and for BW/TBW on 21 Aug with Baythroid at 0.033 lb [AI]/acre. Infestations of larvae and square damage were monitored on 26 Jul, 1 and 8 Aug by examining 25 squares/plot. Yields were determined by mechanically harvesting the center 2 rows of each plot on 30 Oct.

Efficacy of Registered and Experimental Insecticides for Control of Corn Earworm and European Corn Borer on Corn Under Natural Infestation, 1996

Abstract Corn was planted at the University of Illinois Vegetable Crops Farm, Champaign, IL in rows 30 inches wide on 26 Jun. A RCB design was used, and each treatment was replicated four times, with two untreated checks per replicate. These two controls within each block were averaged for analysis. Each plot was 4 rows wide X 50 ft long. Insecticides were applied to the middle rows of each plot; the two outside rows were left untreated, leaving two untreated rows between each treatment. Treatments were applied with a modified John Deere 6000 high-clearance sprayer with a rear-mounted boom. Three Conejet (TXVS-8) hollow cone nozzles per row; two attached to drops allowing spray to be directed towards the ear zone and one nozzle positioned directly over the row. Sprays were delivered with a compressed-air system calibrated to deliver 29.5 gpa at 40 psi and 2.5 mph. A pre-silk application of all treatments was made on 15 Aug, in response to extremely high ECB moth flights. Silk sprays were applied on 20, 24, and 28 Aug; 1 and 6 Sep, beginning at 12% silk. At maturity, twenty-five ears were harvested per treatment from each replication (100 ears/treatment) on 10 Sep. Ears were husked and evaluated and the number of damaged ears, pest species, larval size and location of ear damage (tip or side) were recorded for each ear.

Efficacy of Selected Insecticides for Boll Worm/Tobacco Budworm Control, 1996

Abstract Twelve treatments were evaluated at the Red River Research Station, Bossier City, LA to determine their efficacy in controlling the bollworm/tobacco budworm (BW/TBW) complex on cotton. The experimental design was a RCB with 4 replications. Plots were planted 3 May and were 4 rows X 100 ft on 40-inch centers. All plots had Temik 15G (0.5 lb [AI]/acre) applied in-furrow at planting. Prior to trial initiation, plots were oversprayed for boll weevils on 4 Jun and 12 Jul (Vy date C-LV at 0.25 lb [AI]/acre); BW/TBW on 14 Jun (Orthene 90SP at 1.0 lb [AI]/acre + Larvin 3.2F at 0.25 lb [AI]/acre), and 29 Jun and 18 Jul (Baythroid 2EC at 0.03 and 0.033 lb [AI]/acre, respectively); and for aphids on 29 Jun and 9 Jul with Lorsban 4EC at 0.5 lb [AI]/acre and Provado and 1.6F at 0.047 lb [AI]/acre, respectively. Insecticide treatments were applied on 23, 30 Jul and 6 Aug. Treatments were applied in 5.9 gpa at 60 psi with TX-3 hollow cone nozzles spaced 20 inches apart (2 nozzles/row). Treatments were applied with a high-clearance sprayer equipped with a CO2-system for spraying-small plots. During and after the trial, all plots were oversprayed for boll weevils with methyl parathion 4EC at 0.33 lb [AI]/acre on 2, 19, 21, 30 Aug ane 6 Sep and for BW/TBW on 21 Aug with Baythroid at 0.033 lb [AI]/acre. Infestations of larvae and square damage were monitored on 25, 31 Jul, 7 and 19 Aug by examining 25 squares/plot. Yields were determined by mechanically harvesting the center 2 rows of each plot on 30 Oct.

Efficacy of Selected Insecticides and Insecticide Mixtures for Aphid Control, 1996

Abstract Eight treatments (insecticides and mixtures) were evaluated at the Red River Research Station, Bossier City, LA, to determine their efficacy in controlling aphids on cotton. The experimental design was a RCB with 4 replications. Plots were planted 18 Apr and were 6 rows X 100 ft on 40-inch centers. Foliar applications were made on 28 Jun with applications being made to the center 4 rows of each 6-row plot. Insecticide treatments were applied in 5.9 gpa at 60 psi with TX-3 hollow-cone nozzles spaced 20 inches apart (2 nozzles/row). Treatments were applied with a high-clearance sprayer equipped with a CO2 system for spraying small plots. Aphid infestations were determined by sampling the first fully expanded leaf from 10 randomly selected plants in the center 2 rows of each plot on 27 Jun, 1 and 5 Jul.

Efficacy of Selected Insecticides Against Field Populations of Beet Armyworm, 1995

Abstract Field tests were conducted at the Northeast Research Stations located at St. Joseph and Winnsboro, LA to evaluate the efficacy of 3 registered and 3 experimental insecticides against beet armyworms on cotton. Each test was arranged in a RCBD and replicated 4 times with plots of 4 rows (40 inch centers) by 50 ft. In Test I, cotton (‘Stoneville LA 887’) was planted on 16 May. In Test I cotton (‘DPL 5690’) was planted on 20 Jun. Treatments for Tests I and II were applied with a high clearance sprayer on 15 and 30 Aug, respectively. In Test I, the sprayer was calibrated to deliver 10 gpa through Teejet X-12 hollow cone nozzles (2/row) at 52 psi. In Test II, the sprayer was calibrated to deliver 11.3 gpa through Teejet X-8 hollow cone nozzles (2/row) at 44 psi. Treatment efficacy was determined by taking 2 drop-cloth 3 ft2 samples of a single treated row. Samples were taken at 3, 5, 7 and 10 DAT on rows 1, 2, 3 and 4, respectively. Data were analyzed using ANOVA followed by means separation according to Fischer’s Protected LSD. No rainfall occurred during the experimental period in Test I. Only a trace (< 0.05 inches) of rainfall was recorded during the experimental period in Test II at 7 DAT and it was not considered sufficient to affect insecticide efficacy.

Control of Two Lepidopterous Cabbage Pests with Recombinant and Kurstaki Bacillus Thuringiensis, Spring 1995

Abstract Greenhouse-grown seedlings planted in Speedling trays 30 Dec were transplanted at 18-inch spacing into 4, 32-inch single-row beds 240 ft long, mulched with black polyethylene on 31 Jan at the Southwest Florida Research and Education Center near Immokalee, Fla. Beds were prepared by fumigating with methyl bromide/chloropicrin 67/33 at a rate of 220 lbs/acre, fertilized with a bottom mix of 800 lbs/acre 5-16-8 and a top mix of 500 lbs/acre 19-0-19, and subsurface irrigated. Plants were sprayed weekly from 6 Feb to harvest with Bravo 720 at 1.5 pt/acre for disease control. Each row of cabbage was a replicated block, the two pairs of which were separated by a 15 ft drive middle, with each pair being separated by 12 ft with a row of collards in between planted 15 Nov to provide pest inoculum. Blocks were divided into 6 plots 40 feet long containing 30 plants. Six treatments were replicated four times in a RCB design. The presence of DBM and CSC larvae was confirmed on 20 Mar and treatments were initiated 21 Mar. All treatments were sprayed weekly for a total of 4 applications at 43 GPA using 5 yellow hollow cone Albuz nozzles per row from a high clearance sprayer at 200 psi of pressure, except the last application which was made with a CO2 backpack sprayer at 50 psi at the same rate. Water was at pH 7.2 and a nonionic surfactant, ASPA 80 was added to the spray at the rate of 16 oz/100 gal of spray. Weekly evaluations were made five to seven days post spray on 10 randomly selected plants per plot. Eight leaves were evaluated per plant, the 5 outer head leaves and 3 inner wrapper leaves. Total number and size of DBM and CSC live larvae for each plant were recorded and percent leaf damage was rated on a 1 to 6 scale where 1 = no damage, 2 = 1%, 3 = 2% to 5%, 4 = 6% to 10%, 5 = 11% to 30% and 6 = > 30% damage. The 20 largest heads per treatment were selected for harvest and graded for marketability based on amount of insect damage to the head and inner 2 wrapper leaves. Heads were considered unmarketable if there was insect damage in excess of 5% on the head or 10% on the wrapper leaves.

Mortality of Lady Beetle Adults and Lacewing Larvae Following Exposure to Semiochemical-Based Corn Rootworm Baits, 1992-93

Abstract Two semiochemical-based corn rootworm baits were evaluated for toxicity to GLW and CLB. Slam, a microsphere formulation containing carbaryl as an active ingredient, was applied with a high-clearance sprayer. A bait mixture of Compel, a feeding stimulant, to which carbaryl was added as the toxicant, was applied by use of a specially designed applicator mounted at the rear of a high-clearance sprayer about 2 m above ground level. Baits were applied at lx, 2x, 3x and 4x the labelled rate (Slam: 1.56 oz [All/acre, Compel + carbaryl: 1.16 oz carbaryl [All/acre) to 10 ft by 30 ft plots of corn grown in rows 40 inches apart. Bioassays were done in the laboratory with GLW larvae and CLB, and WCR adults exposed to baits on excised whole leaves taken from the field plots. Bioassays for WCR and CLB were repeated four times in a randomized complete block design with 4 replications. Controls were untreated corn leaves. CLB and WCR were confined in 4 by 4 inch clear plastic cages, 10 insects per cage, held in place over each corn leaf by rubber bands. Bioassays for GLW were done twice in a randomized complete block design with 8 replications, using treated leaves from the same plots used for the first two groups of CRW and CLB. Because of their cannibalistic nature, GLW larvae were exposed to treatments singly in ½ inch clear plastic boxes clipped to treated corn leaves. All test insects were starved for 24 hr prior to use.

Control of Boll Weevil in Cotton with Selected Insecticides, 1995

Abstract Two tests were conducted to evaluate the efficacy of selected insecticides against BW in cotton planted 12 Apr. Plots consisted of 4 rows (40 inch centers) X 50 ft in both tests. Treatments were arranged in a RCB design with 4 replications. Insecticides were applied on 7, 10, 12, 14, 17 Jul in Test II and on 10, 12, 14, 17 Jul in Test II. Applications were made with a high clearance sprayer calibrated to deliver 6 gpa through TX-8 hollow cone nozzles (2/row) at 46 psi. Treatments were evaluated by examining 50 cotton flower buds (squares) per plot 2-4 DAT for evidence of BW damage. No additional foliar insecticides were applied to the plots during this test. The test area received 0.1, 0.1 and 0.3 inches rainfall on 10, 14 and 15 Jul, respectively. Data were analyzed with ANOVA, and means were separated according to DMRT.

Efficacy of Fipronil and Provado Against Tarnished Plant Bugs in Cotton, 1994

Abstract A test was conducted to evaluate the efficacy of Fipronil, Provado and Vydate (standard) against a heavy infestation of TPB during Aug at the USDA Southern Insect Management Laboratory, Stoneville, MS. Cotton was planted on 25 May. Treatments were arranged in a RCBD with 4 replications of 16 rows X 80 ft plots. Natural infestations were allowed to infest plots. Treatments were applied on 11 and 17 Aug with a John Deere high clearance sprayer with a CO2 charged delivery system calibrated to deliver 6 gpa at 40 psi through 2, TX-6 nozzles equally spaced per row. Treatments were sampled on 15 Aug and 19 Aug with a standard 15 inch diam sweep net by counting the combined populations of adults and nymphs in a 25-sweep sample/plot.

Evaluation of Insecticide Application Timing on Sorghum Midge Injury to Grain Sorghum, 1995

Abstract The test was conducted at the Macon Ridge Location of the Northeast Research Station in Franklin Parish, LA. Plots (28 ft X 8 rows) were planted on a Gigger-Gilbert silt loam on 15 Jun in a RCB design with 5 replications. Karate 1EC at 0.02 lb (AI)/acre was applied with a high clearance sprayer equipped with a CO2 charged system calibrated to deliver 9.3 gpa at 46 psi and 3.3 mph through TX-8 hollow-cone nozzles (2/row). Application timing for each treatment was determined by selecting and tagging 20 plants from the 2 center rows before spraying. For the 50% and 90% panicle emergence treatments, 10 and 18 plants, respectively, had panicles completely emerged with no open flowers. For the 20, 50 and 90% flowering treatments, 4, 10 and 18 of 20 tagged plants per plot, respectively, had flowering panicles. A panicle was considered to be flowering when the upper 25% portion had open spikelets. Treatments were applied on 28 Jul for the 50 and 90% panicle emergence and on 31 Jul for the 20, 50 and 90% panicle flowering. Sorghum midge damage to seed heads was evaluated on 24 Aug by estimating percent blasted kernels on each tagged plant. Sorghum seed yields were obtained on 8 Sep by manually harvesting panicles from the 20 tagged plants and by mechanically harvesting the entire 2 center rows in each plot.

Use of Labeled and Experimental Insecticides for Control of European Corn Borer on Sweet Corn in Wisconsin, 1995

Abstract ‘Heritage’ sweet corn was planted at the Arlington Agriculture Research Station, Arlington, WI at 23,000 seeds per acre on 15 June. Each treatment was 6 rows wide and 60 feet long, arranged in a RCBD, replicated four times. The sprays were applied 6, 11, 17 and 25 August. All treatments were applied with a high clearance sprayer equipped with D2/23 TeeJet disc-core nozzles and delivered 10.76 gallons of finished spray per acre at 40 PSI when driven at 2.5 MPH. Plots were evaluated 8 September by removing 25 ears per treatment and recording number of damaged ears and the size of larvae present. “Early” ECB larvae were shorter than lA inch, “mid” larvae are longer than ¼ inch but shorter than Vi inch, and “late” larvae were longer than ¾ inch.

Insecticide Efficacy Against Tarnished Plant Bugs on Seedling Cotton, 1995

Abstract Cotton was planted 11 May into plots consisting of 2 rows (40 inch centers) X 25 ft at the Macon Ridge Location of the Northeast Research Station. Treatments were arranged in a RCB design with 3 replications. Insecticides were applied with a high clearance sprayer calibrated to deliver 10 gpa through TeeJet TVS 8001 flat fan nozzles (2/row) at 38 psi. The cotton plants were in the pre-square development stage and averaged 5-6 nodes at the time of treatment. Cotton seedlings were infested with tarnished plant bug adults at 2 h after treatment and again at 3 DAT by placing the insects in nylon mesh cages, and then securing the cage over the plant terminal. Two cages (1 per plant) were placed in each plot with each cage containing 5 tarnished plant bugs. Mortality of tarnished plant bugs was recorded 2 d after the plants were infested. No rainfall was recorded during this test. Data were analyzed with ANOVA, and means were separated according to DMRT.

Evaluation of Selected Insecticide Combinations Against Boll Worm/Tobacco Budworm in Louisiana, 1995

Abstract The efficacy of selected insecticides was evaluated against BW/TBW at the Macon Ridge location of the Northeast Research Station. Cotton seed was planted 12 Jun in plots consisting of 4 rows (40 inch centers) X 50 ft. Treatments were arranged in a RCB design and replicated 4 times. Applications were made with a high clearance sprayer calibrated to deliver 6 gpa through Teejet TX-8 hollow cone nozzles (2/row) at 46 psi. Insecticides were applied on 8, 11, 14, 18 Aug and 11 Sep. Treatments were evaluated by examining 50 flower buds (squares) per plot on 11, 14, 22 Aug for evidence of BW/TBW and boll weevil damage. Data reported for boll weevil represent a mean across all sample dates. The plots were mechanically harvested on 16 Oct to determine seed cotton yields. The test area was irrigated by an overhead sprinkler “as needed” during the season, but not within 48 h of treatment applications. Rainfall did not influence the effects of these treatments. Data were analyzed with ANOVA, and means were separated according to DMRT.

Control of Tarnished Plant Bugs in Cotton with Selected Insecticides, 1995

Abstract Six insecticide treatments were evaluated against tarnished plant bugs in cotton at the Macon Ridge Location of the Northeast Research Station. Cottonseed was planted 1 May in 4 rows (40 inch centers) X 50 ft. Treatments were arranged in a RCB design with 4 replications. Insecticides were applied on 7 Jul with a high clearance sprayer calibrated to deliver 6 gpa through TeeJet TX-8 hollow cone nozzles (2/row) at 46 psi. Treatments were evaluated 3, 5, and 7 DAT by sampling the plots with a standard 15 inch diam sweep net. Also, to estimate actual mortality values for the treatments, field-collected tarnished plant bug adults were caged on 5 plants within each plot at 4 DAT. Five adults were introduced into a small nylon mesh cage which was placed over the plant terminal. Mortality of caged tarnished plant bugs was recorded 2 d after infestation (6 DAT). No rainfall was recorded during the test. Data were analyzed with ANOVA, and means were separated according to DMRT.

Control of Southern Armyworm with Bacillus Thuringiensis in Staked Tomato, Fall 1994

Abstract Greenhouse raised tomato seedings “Florasette” were planted 8 Sep. 1994, 18 inches within the row on six subirrigated beds, 240 ft long, 32 ft wide on 6 ft centers. Beds had been fumigated with methyl bromide + chloropicrin 67/33 at a rate of 2201b/acre and mulched with whiteside polyethylene. Each of 4, 125 ft blocks was divided into 4, 3-row plots 25 ft long plus 2.5 ft walkways. Plants were sprayed weekly with an alternating combination of Maneb 80 WP at 1 lb/acre plus Kocide 101 at 31b/acre and Bravo 720 at 1.5 pt/acre for disease control. Plants were inoculated on 5 Oct with beet armyworm and on 19 Oct with SAW on 19 Oct to supplement natural populations by applying 2-3 neonates (2-3 per plant) in Grito-O-Cobs (20-40 mesh) to foliage with a “bazooka” gun. Treatments and spray schedules are given in Tables 1 and 2. Spray was delivered weekly for 7 weeks starting in 21 Oct using a high clearance sprayer equipped with yellow hollow cone Albuz nozzles at 200 psi pump pressure. Configuration for the first 4 applications was 9 nozzles per row, one overhead and four each side calibrated to deliver 89 GPA. An additional nozzle per side drop was added for the last 3 applications to deliver 110 GPA. Larval populations were evaluated weekly from 21 Oct to 29 Nov on 6 ft of row from the center of each 3-row plot in two-plant (between-stake) units. Larvae were counted in 3 size categories: small, medium and large but only medium and large are reported. Fruit of marketable size was harvested on 21 Nov & 02 Dec and graded on a commercial table with weights and numbers recorded.

Control of Soybean Looper and Beet Armyworm in the Macon Ridge Region of Louisiana, 1995

Abstract Two tests were conducted at the Macon Ridge location of the Northeast Research Station to evaluate the efficacy of selected insecticides against soybean looper and beet armyworm. Plots in both consisted of 4 rows (40 inch centers) X 50 ft, planted 15 Jun and arranged in a RCB with 4 replications. Insecticides were applied in both tests on 23 Aug with a high clearance sprayer calibrated to deliver 11.5 gpa through Teejet TX-8 hollow cone nozzles (2/row) at 44 psi. Treatments were evaluated at 2 and 7 DAT using two 25-sweep samples/plot with a standard 15 inch diam sweep net. Rows 1 and 2 were sampled 2 DAT and rows 3 and 4 were sampled 7 DAT. No rainfall occurred during these tests. Data were analyzed with ANOVA, and means were separated according to DMRT.

Evaluation of Insecticide Combinations Against Boll Worm/Tobacco Budworm During Late Season in Louisiana, 1995

Abstract This test was conducted at the Macon Ridge location of the Northeast Research Station. Cotton was planted 12 Jun in plots consisting of 4 rows (40 inch centers) X 50 ft. Treatments were arranged in a RCB design, replicated 4 times. Applications were made with a high clearance sprayer calibrated to deliver 6 gpa through Teejet TX-8 hollow cone nozzles (2/row) at 46 psi. Insecticides were applied on 8, 11, 14, 18 Aug and 11 Sep. Treatments were evaluated by examining 50 flower buds (squares) per plot for evidence of BW/TBW damage. The plots were mechanically harvested on 16 Oct to determine seedcotton yields. The test area was irrigated by an overhead sprinkler “as needed” during the season, but not within 48 h of treatment applications. Rainfall was not a factor influencing treatment efficacy in this test. Data were analyzed with ANOVA, and means were separated according to DMRT.

Control of Boll Weevil and Tarnished Plant Bug in Cotton with Selected Insecticides, 1995

Abstract The efficacy of 3 methyl parathion formulations were evaluated against BW and TPB in non-irrigated cotton planted 10 May. Plots consisted of 4 rows (40 inch centers) X 50 ft. Treatments were arranged in a RCB design with 4 replications. Insecticides were applied on 3, 7, 10, 12, 17, and 20 Jul. Applications were made with a high clearance sprayer calibrated to deliver 6 gpa through Teejet TX-8 hollow cone nozzles (2/row) at 46 psi. Treatment efficacy against BW was evaluated by examining 50 cotton squares (flower buds) per plot 2-4 DAT for evidence of damage. Treatments were evaluated for TPB efficacy by sampling the two center rows with a standard 15 inch diam sweep net and recording the number of adults and nymphs in a 40 sweep sample/ plot on 10 Jul. The test area received 1.1, 5.4, 0.04, 0.15, 0.29, 2.16 and 0.57 inches rainfall on 5, 6, 10, 14, 15, 19 and 21 Jul, respectively. Data were analyzed with ANOVA, and means were separated according to DMRT.

Efficacy of Selected Insecticides Against Tarnished Plant Bugs, 1995

Abstract Ten insecticide treatments were evaluated for efficacy against tarnished plant bugs in cotton at the Macon Ridge Location of the Northeast Research Station near Winnsboro, LA. Cottonseed was planted 1 May in 4 row plots (40 inch centers) X 50 ft. Treatments were arranged in a RCB design with 4 replications. Insecticides were applied on 24 Jul with a high clearance sprayer calibrated to deliver 6 gpa through TeeJet TX-8 hollow cone nozzles (2/row) at 46 psi. Treatments were evaluated 3 and 7 DAT with a standard 15 inch diam sweep net by counting both tarnished plant bug adults and nymphs in a 10 sweep sample/plot. No rainfall was recorded during the test. Data were analyzed with ANOVA, and means were separated according to DMRT.