Pretreatment Counts Research Articles

Southwestern Corn Borer Control on Irrigated Corn, 1997

Abstract Seven insecticide treatments were evaluated for control of second-generation southwestern corn borer on irrigated corn at the Panhandle Research Station, Goodwell, OK. Each treatment was applied to plots measuring 7 ft X 25 ft and replicated 4 times in a RCB design. On 5 Aug, pre-treatment counts of egg masses collected during pollen shed indicated SWCB populations were 2-3 times higher than the economic threshold. Insecticide treatments were applied on 6 Aug with a CO2-charged hand held sprayer through 0015 flat-fan nozzles at 30 psi for a total volume of 20 gpa. On 26 Aug, 10 plants per plot were split from root to tassel and evaluated for the number of borer-induced tunnels and borer larvae. Plots were harvested for yield on 3 Oct. Data were subjected to ANOVA and individual means compared by Fishers protected LSD.

Impact of Spray Volume and Wetting Agent on Efficacy of Aerial Insecticide Applications to Man-Age First-Generation European Corn Borer Larvae in South Dakota, 1997

Abstract Field plots were established in central South Dakota near Letcher to evaluate aerially applied insecticide treatments for control of first-generation ECB larvae. The field was planted on 11 May at a rate of 20,400 kernels per acre. The study was carried out to determine the impact of Silwet™ wetting agent and spray volume on the effectiveness of Warrior 1 EC insecticide. Pre-treatment counts revealed an average of 2 ECB larvae (ca. 50% each of 2nd- and 3rd-instars) existed per plant. A strip-plot ex-perimental design was used, and each strip contained 4 replicates. Sampling was conducted within a 32-row subplot (30.5 m by 100 m) for each treatment area. Insecticides were applied on 13 Jul at whorl (ca. 2 d before tasseling) stage in 15.2-m swaths at a speed of 110 mph using a Piper Brave aircraft. A Crop Hawk system was mounted on the aircraft to monitor and regulate spray flow through CP™ nozzles at 25 psi. Treatments consisted of Warrior 1 EC at 0.025 lb (AI)/acre in a spray volume of 2 or 5 gpa. Additionally, each of these spray volumes was evaluated with or without Silwet™ (wetting agent), and all were compared with an untreated control. Approximately one month after insecticide applications (8 Aug), 40 plants in each plot were randomly selected, split vertically and examined for ECB cavity (tunneling) damage. The number and length of ECB cavities were recorded and analyzed using the ANOVA procedure and means were compared by LSD.

Control of Silverleaf Whitefly on Tomato with Sucrose Esters, Insect Growth Regulators, and a Synthetic Pyrethroid/Organo-Phosphate Tank Mix, 1995

Abstract Commercially grown greenhouse seedings exposed to a greenhouse colony of SLW for 5 days were planted 27 Feb 1995 in single rows at 18-inch spacing on 12 black sided plastic mulched beds 32 inches wide and 240 ft long on 6-ft centers. Beds had been fumigated with a 67/33% mixture methyl bromide and chloropicrin at a rate of 2201b/acre and were subsurface irri-gated. Four blocks, 3 rows wide, were divided into 10 plots 24 ft in length to accommodate an RCB with 4 replications and 10 treatments. Plants were sprayed weekly for disease control with an alternating combination of Maneb 80 WPat 1.5 lb/acre plus Kocide 101 at 2 lb/acre and Bravo 720 at 2pt/acre. Biobit (Bacillus thuringiensis kurstaki) was added to the disease control sprays weekly at the rate of 1 lb/acre to control the southern armyworm, Spodoptera eridania. Weekly treatments commenced on 23 Mar and terminated on 8 May with the exceptions of CGA-215944 + fenoxycarb which was sprayed twice on 23 and 31 Mar and V-71639 which was sprayed every 14 days for a total of 4 applications. Latron CS-7 was tank-mixed at 16 oz/100 gallon spray as a sticker spreader for all treatments. Spray mixtures of synthetic and natural sugar isolates were made by dissolving 23 grams of ester in 100 ml of ace-tone and 100 ml of methanol, then adding 28 ml of Latron CS-7 adjuvant before mixing with water to make a 3% sugar ester spray mixture. [Spray was delivered using a high-clearance sprayer through “ATR yellow” Albuz® hollow-cone nozzles at 200 psi pump pressure. Four nozzles per row were used through 5 Apr calibrated at 33 gpa, increasing to 6 nozzles and 61 gpa on 12 Apr. and then to 8 nozzles and 81 gpa for the duration.] Sugar ester (SE) treatments were put out at 0.3% w/v throughout the trials whereas concentration of other treatments was adjusted according to gallonage to achieve the required rate per acre. Plants were evaluated weekly for the presence of whitefly adults, nymphs, pupa, and parasitized pupae. Adult whiteflies were sampled with a beat pan made from 9.5" X 13" pie pan painted black and covered with an oil/detergent mixture. The center six plants in each row of each 3-row plot were sampled and the numbers recorded as a total for each row. Nymphs and pupae were sampled by removing a trifoliate leaf from around the 6th node of four until 4 April when two randomly selected plants per row for a total of 12 and then 6 leaflets per plot. Counts were made under a stereoscopic microscope within a 0.5-cm2 template and later a 1-cm2 template on each side of the midvein of each leaflet for a total of 12 cm2 per row or 36 cm2 per plot. Sprays were commenced when pre-treatment counts reached 4 nymphs per 36 cm2 and 1 adult per beat (17 March). Plants were inspected weekly for symptoms of tomato mottle geminivirus (ToMoV). All fruit of marketable size on 10 plants per plot was harvested on 9 May 95 and fruit of marketable quality graded for size on a commercial-type line. Unmarketable fruit was inspected for damage by pinworm, southern armyworm or other causes.

Control of Panicle Caterpillars on Sorghum, 1997

Abstract Insecticides were evaluated for control of panicle caterpillars at the Texas Agricultural Experiment Station Research Farm near College Station, TX. Panicle caterpillars included corn earworm, fall armyworm, and sorghum web-worm. Seed of hybrid sorghum (ATx399 X RTx430) was planted 16 Jun on rows spaced 30 inches apart. Insecticide treatments were compared in plots, 8 rows X 40 ft long, arranged in a RCB design with 4 replications. Insecticides were applied to the middle 2 rows of plots when sorghum was in the dough stage. Insecticides were applied on 9 Sep between 0930 and 1100 h CDT by using a hand-held backpack sprayer with 4, TX-3 hollow cone nozzles at 35 psi. producing a finished spray volume of 4.9 gpa. Caterpillar abundance was assessed by using the “beat bucket” technique to sample 10 panicles per plot. A pre-treatment count of headworms and webworms was made just prior to insecticide application. Post-treatment counts were made on 10(1 DAT) and 12 Sep (3 DAT). Data were statistically analyzed by using ANOVA and LSD. Percent control was calculated by using the Henderson and Tilton (1955) sampling formula.

Foliar Sprays to Control Green Peach Aphidsl on Spinach, 1996

Abstract Spinach was planted on 5 Sep in a commercial field in Tasley, VA. Each plot was 5 ft wide X 15 ft long and contained 6 rows of plants. The test consisted of 9 treatments replicated 3 times in a RCB design. A pre-treatment count of live aphids on 10 randomly picked leaves/plot was made in the plots designated to be untreated checks immediately prior to the first application on 5 Dec. This count indicated moderate to heavy GPA pressure with an average of 412 live aphids/10 leaves. Subsequent counts to evaluate efficacy were made in a similar manner on the dates indicated in the table. The treatments were applied with a three flat-fan (8003, T Jet) nozzle boom delivering 46 gal water/acre at 40 psi. A second application was made on 11 Dec after a prolonged rainy period from the evening of 5 Dec through 9 Dec totaling 1.27 in. Latron B-1956 at a rate of 8 fl oz formulation/100 gal water was added to each treatment, except for the Pymetrozine 50WP at 0.045 lb(AI)/acre + Silwet.

Control of Insect Pestsl On Fall-Seeded Canola, 1997B

Abstract Plots were established in a RCBD with 4 replicates of 20 X 30 ft at the USDA-ARS Western Regional Plant Materials Introduction Center at Central Ferry, WA, on 10 Oct. Treatments were made at full bloom with a CO2-powered backpack sprayer at 20 gpa at 20 psi on 21 May except for Gaucho 75 ST applied as a seed treatment at planting. All sprayed insecticides were buffered to pH 5.0. Treatments were evaluated for pre-treatment count 215 DAE, 7 DAT (222 DAE), 12 DAT (227 DAE), and 25 DAT (240 DAE) by counting the number of CA colonies per m2 (6.6 linear ft of row) with mean number of CA per colony. CSPW were counted with per 180° sweeps of a 14-inch sweep net on evaluation dates. Counts of CSPW exit holes per 100 pods per replicate were made at harvest, and yield data was collected.

Control of Insect Pests on Fall-Seeded Canola, 1997A

Abstract Plots were established in a RCBD with 4 replicates of 20 X 30 ft at the USDA-ARS Western Regional Plant Materials Introduction Center at Central Ferry, WA on 10 Oct. Treatments were made at full bloom with a CO2 powered backpack sprayer at 20 gpa at 20 psi on 21 May except for Gaucho 75 ST applied as a seed treatment at planting. All sprayed insecticides were buffered to pH 5.0. Treatments were evaluated for pre-treatment count 215 DAE, 7 DAT (222 DAE), 12 DAT (227 DAE), and 25 DAT (250 DAE) by counting the number of CA colonies per m2 (6.6 linear ft of row) with mean number of CA per colony. CSPW counts were made on evaluation dates with 180° sweeps with a 14-inch sweep net. Counts of CSPW exit holes per 100 pods per replicate were made at harvest, and yield data were collected.

Twospotted Spider Mite on Marigold in the Greenhouse, 1996

Abstract In late May 1996, 108, 6-inch-tall marigolds were planted in 6 inch pots at the Pesticide Research Center, Michigan State University. The plants were infested with twospotted spider mites, raised on bean plants in the laboratory, by placing 3 infested leaves on each test plant. Pretreatment counts were made on 13 Jun by collecting 4 leaves from each plant and counting the number of mites on the underside of each leaf with a dissecting microscope. The plants were then blocked by the pretreatment counts. All treatments were sprayed on 19 Jun with an R&D CO2 sprayer with an 8008 flat fan nozzle at 50 psi to first runoff. Each treatment was replicated 6 times with each replicate being an individual plant. Reps 1-3 were of the variety ‘Orange Boy’ and reps 4-6 were of the variety ‘Little Devil Yellow’. Post-treatment counts were made on 21 Jun, 25 Jun, 1 Jul and 9 Jul in the same manner as the pretreatment counts.

Green Peach Aphid Control with Foliar Sprays, 1996

Abstract Experimental plots were established on the UI Research and Extension Center, Kimberly, Idaho. Potatoes were planted on 25 Apr and irrigated by solid set sprinkler. The soil type was Portneuf silt loam. Six treatments and one untreated check plot were replicated four times in a RCB design. Individual treatment plots were 4 rows (36 inch row spacing) wide by 25 ft long with 5-ft alleyways separating the plots. GPA was mass reared on greenhouse sweet pepper plants (‘California Wonder’) for release into individual plots. Aphid releases were made into test plots on 27 Jun and again on 8 Jul. A total of four heavily infested plants were released per plot. Treatment sprays were broadcast applied using a CO2 pressurized backpack sprayer (30 psi) and delivering 20 gpa finished S (four, 10X hollow cone nozzles). Aphid counts were made from non-destructively sampled leaves at random from the top, middle and bottom sections of plants in the center two rows of each plot. The data collected and presented are the total no. of aphids per 20 leaves. On 5 Jul, pre-treatment count was taken at which time it was determined that aphid populations were too low to treat. On 10 Jul, a second pre-treatment count was made and all treatments were applied 11 Jul. All plots received applications of Carbaryl as needed to control Colorado potato beetle. Data were analyzed using ANOVA and Newman-Keuls multiple means comparison (P = .05).

Control of Colorado Potato Beetle, 1996C

Abstract This trial was located in a non-irrigated commercial potato field in the southern Red River Valley of the North. Plant spacing was 36 inches between rows and 12 inches between plants within rows. Treatments were arranged in a RCB design with 3 replications. Plots consisted of a single treatment row. Treated rows were separated by a row of untreated plants. For evaluating the treatments and determining plot size, counts of CPB larvae in each plot were recorded. Plots were of variable length (approximately 15-20 feet). The number of plants constituting a plot was determined on the basis of pre-treatment counts of CPB larvae so that plots averaged approximately 175 larvae, including small (instar 1-2) and large (instar 3^1) larvae. Small larvae predominated in the population (mean pre-treatment counts per plot: 138 small, 38 large). Treatments were applied with a CO2pressurized sprayer fitted with a Teejet 8O03-E fiat fan nozzle, delivering 60 gpa at 35 psi. Pre-treatment counts and folaii applications were made 14 Jul. Post-treatment counts of larvae were made 1 d after application. Percent control was calculated as (1-(post-treatment count/pre-treatment count)) X100. The data were subjected to ANOVA after arcsinV(x) transformation.

Alfalfa Weevil and Pea Aphid Control on Alfalfa, 1996

Abstract Test plots were established near Filer, Idaho. The soil type was Portneuf silt loam and the field was irrigated by surface flow. Four treatments and an untreated check were replicated four times in a RCB design. Each individual test plot was 25 X 25 ft. Sprays were applied using a CO2 pressurized backpack sprayer using 30 psi and delivering 20 gpa with four, 10X hollow cone nozzles. Sampling was accomplished by taking five, 90° pendulum sweeps (15-inch diam sweep net) per plot. Counts were made of all alfalfa pest species present as well as all beneficial insects. A pre-treatment count was made and all treatments were applied on 17 Jun. Additional counts were made at 48 h, 7 and 9 DAT. Data were analyzed using ANOVA and Neuman-Keuls multiple means comparison (P = 0.05).

Control of Spider Mites on Oleander Under Greenhouse Conditions, Fall 1996

Abstract Oleander cuttings were rooted in 15 cm pots and allowed 8 wk growth (25-30 cm tall) before use. The plants were fertilized once with Osmocote (14-14-14) and irrigated every other day for three minutes by drip system. By the time we conducted the trial, the plants were moderately infested with twospotted spider mites. A single terminal leaf (fully expanded) was arbitrarily selected to monitor the efficacy of selected pesticides. Mites were brushed off the leaf using a mite-brushing machine, and the number of mites (all stages except eggs) was recorded. A pre-treatment count was taken on 11 Oct and was followed by a single treatment application. Post-treatment counts of live mites were taken weekly for three wks. Spray treatments were applied using a backpack sprayer at approximately 25 psi. Granular treatments were weighed on a balance in the greenhouse, placed directly on the soil in the pot, and irrigated into the soil for three min. A RBC design was used with 5 replicates per treatment. An ANOVA was performed on the data set, and Ryan’s Q was used to separate the means.

Control of Rose Aphids in a Landscape Setting, Summer 1996

Abstract Roses are routinely planted on the UCR campus as part of the landscape. They are rarely treated for pest problems and typically exhibit moderate infestations of the more common pests. A single planting of roses approximately 30 m2 was used to determine the efficacy of selected pesticides against the rose aphid, Macrosiphum rosae (L.). The plants were arranged in seven rows of eight plants each, one meter apart. The average maximum and minimum temperatures during the trial were 98.2°F and 62.9°F. The roses were irrigated for 8 minutes two times each night three days a week, and no rain occurred during the trial. Granular applications were applied the night before spray treatments, 7 Aug, to allow an irrigation cycle to occur. Two leaves and two flowers were collected from each rose plant at each sampling time. Aphids were collected from the samples by placing the leaves and flowers in a quartsized food container filled with 80% ethanol. They were shaken for thirty seconds, and the solution was filtered through a Buchner funnel. Aphids were collected and counted on a piece of filter paper in the funnel. A pre-treatment count was taken on 6 Aug. Ten treatments and an untreated check were set up on 8 Aug. Post-treatment counts of aphids were taken weekly for four weeks after treatment (WAT). The data were analyzed using ANOVA and DNMRT was used to separate means.

Fall Mole Cricket Control on Golf Courses, 1995C

Abstract This experiment was conducted on fairways 10, 12, 13, 15 and 18 at the Jackson County Golf Course in Jackson County on the Gulf Coast of Mississippi. Soil type was a sandy clay loam. Mole crickets were midinstar nymphs Experimental design was a RCB with 4 replications. Each replication was 2,000 ft2. Treatments were made on 24 Oct. Granular formulations were applied with a Scotts ProTurf, hand-pushed spreader. Liquid and wettable powder formulations were applied with a Solo Knapsack sprayer using a fan nozzle at 25 psi, and a spray volume of 2 gal per 2,000 ft2. Rainfall from 24 Oct to 11 Nov was a total of 16.41 inches during this study. All plots received 0.33 inch water within 1 hour after applications. Mole cricket damage was rated using a 1 m2 frame divided into nine equal, square-shaped sections. The frame was placed on the ground at 10 locations/replicate. The presence of mounds and tunnels was determined visually and by touch. Damage ranged from zero (no damage in any of the nine sections) to nine (nine sections contained mounds and/or tunnels). Pretreatment counts were made on 24 Oct and post-treatmem counts were made on 31 Oct and 6, 13 and 20 Nov.

Control of Yellowmargined Leaf Beetle on Turnip, 1995

Abstract Insecticide treatments were applied at labeled rates on 11 May and 18 May at the Burden Research Plantation, Baton Rouge, LA, 1995 on turnip. A CO2 powered backpack sprayer calibrated to deliver 40 gallons per acre at 30 psi through a spray boom with three nozzles was used. Experimental plots consisted of single rows (30 ft long, 4 ft wide) arranged in a RCB design with 4 replications. Insect counts were made with beat sheets (3 X 2) on 10 and 17 May (pre-treatment counts) and 12 and 19 May (post-treatment counts). Three samples were taken from each plot and the number of insects present of each species was recorded.

Control of Twospotted Spider Mites in Peanuts, 1994

Abstract This study was conducted to evaluate the efficacy of selected miticides for control of TSSM. One portion of a field was selected because of a uniform infestation of TSSM. The field selected was planted on 36-inch rows on 2 Jun. Management practices were determined by the grower, but did not include any insecticides or miticides. The selected area became heavily infested with TSSM because of lack of moisture from inoperable irrigation nozzles. Each plot was 25 ft long by 2 rows wide. Plots were arranged in a RCBD with four replicates. Treatments were applied on 5 Sep using a CO2 pressurized backpack sprayer calibrated to deliver 20 gpa at 32 psi through one 8004E flat fan nozzle per row. To avoid overspray from adjacent plots, treatments were separated by 2 rows of peanut. Pretreatment counts were taken on 5 Sep just prior to application. Post-treatment counts were made on 13 Sep and 18 Sep, or 8 and 13 DAT, respectively. Treatments were evaluated by comparing mite control on 5 randomly selected plants per plot. Population densities of mites were estimated by sampling an area of 0.35 in2 (2.25 cm2) on each plant in the lower, middle and upper canopy. This sampling scheme resulted in checking 15 leaflets per plot. Yields were determined by digging, combining, drying and weighing peanuts from both rows of each plot. Data were analyzed using ANOVA and LSD procedures.

Analysis of bronchoalveolar lavage fluid in patients with chronic hepatitis C before and after treatment with interferon alpha.

BACKGROUND: Previous studies have shown that patients with idiopathic pulmonary fibrosis (IPF) were more likely to be seropositive for hepatitis C virus (HCV) than normal controls, and that patients with...

Evaluation of Insecticides Against Lepidopterous Pests During Bloom on Blueberries, 1996

Abstract This study was conducted in a ‘Bluecrop’ blueberry field near Whitesbog, NJ. Blueberry bushes were approximately 5 ft tall and spaced 9 X 4 ft apart. Treatments were arranged in a RCB design, replicated 5 times with each replication consisting of 6 bushes in 2 rows. Two unsprayed rows between blocks and 8 unsprayed bushes between treatments within a block served as buffers. Insecticides were applied with a CO2 pressurized Model T backpack sprayer (R & D sprayers) equipped with a Tee Jet hollowcone (4 VS) nozzle calibrated to deliver 30 gal/acre at 40 PSI. Insecticides were applied twice on 14 May and 24 May approximately at 40 and 80% bloom, respectively. Spray adjuvants, Nu-Film 17 (4 oz/acre) and Latron B-1956 (0.12% v/v) were included in all B.t. and Confirm treatments, respectively. GM eggmasses were obtained from USDA-APHIS facility at Otis Air Base in Cape Code, MA, to augment larval populations in the field plots. Eggmasses were stapled to the bush on 4 May at the rate of one eggmasses per bush. Eggmasses began hatching on 6 May and larvae were well distributed on the bushes within a week after hatching. Larval populations were assessed by sampling 25 clusters from each of 4 randomly selected bushes/replicate for a total of 100 leaf and flower clusters/replicate on 13 May (pretreatment count), and 24 May and 1 Jun (post-treatment counts). Leaf and flower clusters were randomly selected from the top, middle and bottom thirds of each bush.

Tobacco Budworm and Hornworm Control in Flue-Cured Tobacco, 1996

Abstract Full-Season Test. In Test 1, flue-cured tobacco, variety K-326, was transplanted on 10 Apr at the Georgia Coastal Plain Experiment Station Bowen Farm. Production practices were used according to Georgia Cooperative Extension Service guidelines and included a preplant tank mixture of Tillam and Devrinol for weed control, Ridomil for blue mold control, and Nemacur for nematode suppression. Fertilizer (6-6-18) was applied in a split application at a rate of 1000 lb/acre. Plots, two rows wide (44-inch row spacing) by 25 ft long, were arranged in a RCBD with 4 replications. Plots were separated on each side with a fallow border row and on each end with a 6-ft wide alley. On 31 May, 9 insecticide treatments were applied using a CO2 powered backpack sprayer equipped with three TX-12 nozzles directed over a single row, delivering 24.5 gpa at 40 psi. The number of live budworms and hornworms on all plants of both rows were recorded from each plot prior to treatment (pre-t) and 3,7,10 and 14 days after treatment (DAT). Plants 2-11 on the second row were harvested on 21 Jun and cured weights were determined by factoring out the moisture. All data were subjected to analysis of variance and the means were separated using DMRT. In Test 2, the K-326 tobacco used in Test 1 was striped of all leaves on 21 Jun, the stalks chopped down to a height of about 20 inches and allowed to regrow. This tobacco was side dressed with 16-0-0 at 100 lb/a after chopping. The plot size, randomization, and design remained the same as in trial 1. On 16 July, pre-treatment counts were made and the 9 treatments plus 2 TD 2344 treatments were applied on the regrowth tobacco. The number of live budworms and hornworms on all plants was recorded from each plot 3,7,10 and 15 DAT. The percent defoliation was visually determined for all plants in each plot on 25 and 31 Jul. All data were analyzed with an analysis of variance (P = 0.05).

Biorational Insecticides for Control of Annual White Grubs on a Golf Course Fairway, 1996

Abstract This study was conducted in Lincoln, NE on a golf course fairway. The turf (20% Kentucky bluegrass and 80% perennial rye) was maintained at a mowing height of ⅝ inches. Thatch accumulation (finger compressed) in the plot area was 0.375 to 0.50 inch. Field conditions at the study site were: soil type, silty clay loam; soil organic matter, 4%; soil pH, 6.2; water pH, 7.0. Environmental conditions at the time of application were as follows: soil moisture 21% by wt; air temperature 84°F; soil temperature 80°F; relative humidity 52%; wind direction and velocity 196° at 4 mph. Plots were 40 inches X 15 ft and the experimental design was a RCB with 4 replications. Liquid applications were applied on 13 Aug 1996 using either a Cushman prototype subsurface applicator designed to place liquid insecticide treatments at the soilthatch interface (avg depth 0.5 inch), or a CO2 sprayer with a TeeJet 8002 nozzle at 30 psi and delivering 3 gal/1000 ft2. Granular insecticides were applied using a pre-calibrated Gandy 24H12 drop spreader. Following applications, plots were irrigated with 0.35 inch of water. Post-treatment precipitation totaled 0.07 inch. Treatments were evaluated 27 DAT on 5 SEP by removing from each plot three, 8-inch diam turf-soil cores (1.05 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs. Pretreatment counts indicated 10-20 SMC/ft2 with 32% first instar, and 68% second instars in the test area.