Plot Sprayer Research Articles

Aphid Control in Canola, 1987

Abstract Plots were located on the Research and Education Center in Princeton, KY. Plots were 9 ft × 15 ft, were replicated 3 times in a completely randomized design (except Test 1 which was a latin square). Foliar insecticides were applied to each plot on 8 Dec in 20 gal/acre, using a CO2 powered plot sprayer. Percent infestation measurements were taken 7 d post application.

Cabbage Seedpod Weevil Control, 1989

Abstract Two insecticides and 2 application timings were tested for control. Plots were located on the Research and Education Center in Princeton, KY. Plots were 6 by 15 ft, consisting of 5, 10 inch rows, arranged in a completely randomized design, and planted using standard agricultural practices. Yields were collected from the central 52 inches by 12 ft area of each plot. Foliar insecticides were applied using a CO2 powered plot sprayer at the equivalent of 29 gal finished spray/acre. Insect populations were sampled by taking 5 sweeps/plot with a standard sweep net. Percent reduction was computed using the following formula; prespray-postspray/prespray × 100. Counts on days 1 and 7 were compared to day 0, while day 8 was compared to day 7. Pod damage was determined by randomly collecting and examining for exit holes, 100 pods/plot/wk for 5 wk after preliminary sampling had indicated that CSPW emergence had begun. The greatest percent damage/plot was used in the analyses.

Control of Russian Wheat Aphid and Bird Cherry-Oat Aphid on Winter Wheat in the Fall, 1988

Abstract Twelve insecticides were evaluated for performance in controlling the named grain aphids, with applications made 4 Oct to soft white winter wheat (growth stage: 2-5 tiller) grown on the Washington State Univ., Irr. Agric. Res. & Ext. Center, Roza Farm, Prosser, WA. Treatments were applied using a CO2 plot sprayer (8001 nozzles with 100 mesh screen) mounted on a bicycle-wheeled carriage. Sprayer output was 19 gal/acre at 30 psi. Plots were 4 × 15 ft (4 rows on 12 inch row spacing), replicated 5 times in a randomized complete block design. Plots were planted 2 Sep (seeding rate: 45 lb/acre). Treatments were evaluated at 3, 8, and 17 DAT, based on aphids/tiller (20 tillers/plot) sampled at random, field-bagged, and subsequently transferred to a Berlese funnel to extract the aphids. Plots were harvested on 10-11 Aug using a Hege combine.

Ovo-Larvicidal Activity of Selected Insecticides, 1989

Abstract A small plot insecticide trial was conducted on the Northeast Research Station near St. Joseph, LA, to compare the ovicidal activity and residual toxicity of selected insecticides against Heliothis spp. on cotton. Cotton was planted on 15 Jun in plots 4 rows (40 inch centers) by 50 ft. Treatments were arranged in a randomized complete block design and replicated 4 times. Insecticides were applied on 23 Aug with a CO2 charged application system mounted on a John Deere high clearance plot sprayer. A total volume of 5 gal/acre was applied through Teejet X-6 hollow cone nozzles (2/row) at 44 psi. No insecticides had been applied on those plots prior to the initiation of this trial. Eggs were collected 4 and 48 h posttreatment from the center 2 rows of each plot. Samples of freshly laid white eggs (10/plot) and a small piece of foliage to which the eggs were attached were removed from the plants and transported to the laboratory. Eggs were individually placed into 1 oz plastic cups partially filled with artificial diet for rearing Heliothis spp. Mortality to eggs and larvae were determined 96 h after each field collection. The surviving cohort of larvae in the control treatments were reared to adults and the species composition was found to be 100% tobacco budworm. A trace amount of rainfall (0.41 cm) was recorded 24 h after treatment, which did wet the adaxial surface of the plant leaves and could have reduced residual efficacy of some treatments.

Construction of a High-Clearance Plot Sprayer

Weed control research includes comparisons of herbicides, spray volumes, carriers, and application times in tall crops such as grain sorghum and corn. To accomplish this, a plot sprayer was constructed on a 15-kW tractor with 1.5-m clearance. Ten spray cans held spray mixes that were propelled by compressed air supplied by a two-cylinder single-stage compressor. Using this sprayer, two people could spray up to 66 plots per h to evaluate herbicides, growth regulators, and insecticides in tall weeds and crops using different speeds, controlled droplet applicators, rope wicks, or air-assist nozzles at low- and high-spray volumes.

Sorghum Greenbug Control, 1985

Abstract This experiment was conducted in Clay County, Nebr. The previous year's crop was soybeans. The experiment was arranged in a randomized complete block design with 5 replications. Plots were 4 rows wide (30-inch spacing) and 30.2 ft long. The 2 center rows were used for insect counts and yield. In-furrow planting-time application of granules was made by applying a preweighed amount of granules from a V-belt seeder into the granule delivery tube mounted on the planter behind the seed tube. Foliar applications were applied on 25 Jul with a CO2-pressurized unit mounted on a bicycle-wheeled plot sprayer. Three nozzles/row were used—1 from each side and 1 over the row. Spraying Systems TX8 hollow-cone tips were used at 40 psi with spray output of 22.5 gal/acre. The number of emerged plants in the 2 center rows of each plot was counted on 20 Jun. Insect population levels were determined by examining 10 plants in the 2 center rows on the stated dates. Plots were harvested on 25 Oct with a Massey 35 combine.

Field Corn, Corn Rootworm Larval Control, 1986

Abstract Corn rootworm planting-time and first-cultivation soil insecticide trials wt conducted at Mead, Neb. The test plots were in trap crop during 1985 and had been in a trap crop (no insecticide)/insecticide test plot annual rotation at least 8 yr. The soil type was a silty clay loam. The experimental design was a randomized complete block with 4 replications. Each replication consist of single-row treatments that were 35 ft long and 30 inches apart. Planting-time application equipment consisted of modified V-belt seeders mounted oi model 80 John Deere® flex planter. Preweighed amounts of insecticide granules were placed on the V-belts and directed into the seed furrow or band over the row in front of the press wheel. Noble® metering units mounted on a hand-powered bicycle applicator were used to apply granular insectici formulations at first cultivation. Liquid insecticide formulations were applied with a small plot sprayer pressurized with C02 . A Tee Jet® 8004 nozzle v used at 30 psi to deliver 16.4 gal/acre. Granules were banded directly over the plant whorl, and liquids were sprayed in a 7- to 10-inch band directed at t plant base. All treatments were immediately incorporated by a cultivator. Corn was planted on 7 May, and first-cultivation treatments were applied 6 Ji Soil moisture conditions were excellent when insecticides were applied. Initial corn rootworm egg hatch was detected on 3 Jun. Stand counts were taken 2 Jun and 15 Oct. Plant evaluations were made on 2 Jun in the planting-time test to determine whether any insecticide treatments adversely affected cc development. Plants were considered abnormal if they were stunted or exhibited deformed growth patterns (i.e., buggy whipping). Rootworm feeding dama - was evaluated (8 Jul, planting-time test; 17 Jul, cultivation test) by digging 5 roots from each treatment row and rating the damage by means of the Iowa 6 scale (1, no feeding to 6, 3 or more nodes of roots completely destroyed). Lodging counts were taken in October. A plant was recorded as lodged if t angle between the soil surface and the plant stem was ≤67.5 degrees. Data were subjected to an analysis of variance, and an LSD test was used for me separation where significant differences occurred.

Field Corn, Corn Rootworm Larval Contorl, 1985

Abstract Three insecticide evaluation studies were conducted for control of mixed populations of northern and western corn rootworm. Experiment I was conducted at the Pennsylvania Agricultural Experiment Station farm at Rock Springs, Centre County, PA. Corn was planted on 15 May using a 6-row John Deere Max-Emerge planter with 30-in row spacing. Insecticides were applied to 15 by 90-ft plots in a randomized complete block design with 4 replications per treatment. Rows 1 and 6 were nontreated guard rows. The plots were thinned to 115 plants per 90 ft of row. On 31 Jul 5 plants from each replication were evaluated for root damage ratings based on the Iowa 1 to 6 system with 6 being the most severe damage. Yield was determined by mechanically harvesting 3 middle rows from each plot for shelled corn. Experiment II was conducted on the Drew Smith farm near Pleasant Gap, Centre County PA. Corn was planted 21 May using a 2-row John Deere Max-Emerge no-till planter with 30-inch row spacing. Insecticides were applied to 5 × 50 ft plots in a randomized complete block design. The Dyfonate encapsulated was applied 22 May with flat fan drop nozzles over the row from a small plot sprayer. Root damage ratings were evaluated over the period of 7 through 9 Aug, taking 5 plants per plot and using the Iowa 1-6 system. On 25 Oct 17.5 ft of row was hand harvested per plot and yield was determined. Experiment III was conducted on the Dan Stoltzfus farm near Mill Hall, Clinton County, PA. Corn was planted on 21 May using the same planter and field design described in experiment II. Root damage was determined on 6 Aug and yield as determined on 23 Oct.

Aphid Control on Wheat in the Spring with Foliar Applied Insecticides, 1986

Abstract Seven insecticides were evaluated as late spring applications to determine their effect on grain aphids and grain yield. Plots were planted on 27 Sep ‘85 using a tractor-mounted 4-row belt-cone Almaco grain drill with double disc openers. Seeding rate was 40 lb/acre. Plots were furrow-irrigated in the spring. Applications were made at milk and soft dough stages of wheat on 3 Jun (Capture and Lorsban only) and 12 Jun ‘86 (Capture excluded), respectively, using a CO2 plot sprayer mounted on a bicycle-wheeled carriage. Sprayer output was 58 gal/acre at 40 psi. Plots were 4 rows (12 inches between rows) by 17 ft in length, replicated 4 times in a randomized complete block design. Aphid control was determined on the basis of Berlese-Tullgren funnel aphid extractions (6 plants/plot/posttreatment sample). Plots were harvested 21 Jul ‘86 with a Hege Combine.

Field Corn, Corn Rootworm Larval Control, 1985

Abstract Rootworm planting-time, soil-insecticide test plots were established at 5 Iowa locations. Two of these locations were also used for cultivation-time tests. The insecticide histories of the test fields were: Nashua and Sutherland—trap crop (no insecticide)/insecticide test plot, yearly alternation for at least the past 4 years; Creston—Counter '85 and '84, no insecticide '83 and '82; Ames—no insecticide '85, Furadan '84 and '82, Counter '83; Newell—no insecticide '85, '83, '82, insecticide test plot '84. The experimental design was a randomized complete block with 4 replications for the root-protection trials and 8 and 12 replications for the Nashua and Sutherland yield trials respectively. All treatments were applied to 50-ft length rows with 30-inch row spacing. The registered-chemical and yield trials had double-row treatments. All other trials had single-row treatments. Granular insecticide formulations were applied with modified Noble® metering units that had been laboratory-calibrated to accurately deliver material at a tractor speed of 4 mph. Liquid insecticide formulations were applied with a self-contained small plot sprayer pressurized with CO2 Lorsban 50W was applied with a Tee Jet® 8010E nozzle at 13 psi to deliver 20 gpa. All other liquids used a 8004E nozzle with 15 psi to deliver 10 gpa. The applicators were mounted on a 2-row John Deere® Max-Emerge™ 7100 integral planter equipped with ripple coulters. Drag chains were used for incorporation. Cultivation-time granular insecticides were applied with hydraulically-driven Noble units mounted on the front of a tractor. Plastic tubes directed the insecticide to both sides of the plant base for basal applications. A bander positioned directly over the plant whorl was used for whorl applications. Liquid applications were sprayed in a 7-10 inch band at the plant base. Treatments were incorporated with a 2-row, rear-mounted cultivator. In late July, rootworm feeding was evaluated by digging 5 roots from each treatment row and rating the damage on the Iowa 1-6 scale (1 equal to no feeding, and 6 equal to 3 nodes of roots completely destroyed). Chemical phytotoxicity was checked by taking stand counts and plant height measurements for each treatment. Lodging counts were taken at harvest time at Nashua and Sutherland. Analysis of variance was used to analyze the data.

Aphid Control in Winter Wheat with Fall Applied Foliar Insecticides, 1986

Abstract Eight insecticides were evaluated to determine their effect on grain aphids, barley yellow dwarf virus (BYDV), and grain yield. Plots were planted on 30 Aug and 3 Sep ‘85 on the Washington State University, Headquarter (trial 1) and Roza (trial 2) Research Farms near Prosser, Washington, respectively, using a tractor-mounted 4-row belt-cone Almaco grain drill with double disc openers. Seeding rate was 40 lb/acre. Plots were 4 rows (12 inches between rows) by 17 ft in length, replicated 4 times in randomized complete block design. Applications were made at the 6-8 leaf seedling stage on 24 Sep ‘85 using a CO2 plot sprayer mounted on a bicycle-wheeled carriage. Sprayer output was 58 gal/acre at 40 psi. Plots were furrow-irrigated in the spring. Aphid control was determined on the basis of Berlese-TuUgren funnel aphid extractions (6 plants/plot/posttreatment sample). Plots were harvested 22-30 Jul ‘86 with a Hege Combine.

Aphid and Virus Control in Winter Wheat, Washington, 1984-85 Crop

Abstract Ten insecticides were evaluated at 2 locations to determine their effect on grain aphids, barley yellow dwarf virus (BYDV), plant growth, and grain yields in winter wheat. Trial 1 was planted with ‘Wanser’ on 31 Aug ‘85 on the Roza Research Farm. Trial 2 was planted with ‘Daws’ on 4 Sep ‘84 on the Headquarters Farm. Both farms are part of the Washington State University Irrigated Agriculture Research and Extension Center at Prosser, WA. Trial 2 was furrow-irrigated in the spring; Trial 1 was not. Aside from the differences stated, the trials were arranged, treated, and evaluated the same. Treatments were applied as foliar sprays on 4 Oct ‘84 (early tillering stage of growth) with a compressed air plot sprayer mounted on a bicycle-wheeled carriage, calibrated to deliver 49 gpa at 40 psi. Plots in each trial were 4 rows (12 inches between rows) 17 ft in length, replicated 6 times in a randomized complete block design. Plots were planted using a tractor-mounted 4-row belt-cone Almaco grain drill with double disc openers. Seeding rate was 40 lb/acre. Aphid control was determined on the basis of berlese funnel aphid extractions (6 plants/plot/posttreatment sample). BYDV was rated visually on 4 Jun 1985 using a 1-6 scale, where 1 = no virus; 6 = severe symptoms. Average height was taken 4 Jun 1985. Plots were harvested 11-26 Jul 1985 with a Hege Combine.

Pea Insect Control, 1985

Abstract Plots were planted 16 May ’85, so that expected pest moth flights would coincide with pea bloom. A randomized complete block design of four blocks contained 16 treatments each 10 ft × 50 ft. The treatments were applied after 10% bloom on 8 Jul with a CO2 activated boom plot sprayer (2.5 mph, 20 gpa, 8002 Tee Jet tips on 19-inch centers). At harvest, 14 days after this treatment, an evaluation of aphids, cutworms, and loopers was made in 10 separate 1-sq ft samples per replicate. Each sample was assessed for the total number of aphids and larvae; the larvae were classified as early instar (E), mid-instar (M), or late instar (L).

Control of Insect Pests of Forage Alfalfa, 1985.

Abstract A 10-yr-old stand of alfalfa located at the Main Station Field Laboratory, Reno, NV was used for this study. Treatments were applied when alfalfa was 14-16 inches tall with 30-40% of terminals showing alfalfa weevil damage. Plots were 25 × 50 ft with treatments replicated 4 times in a randomized complete block design. Sprays were applied with a CO2 activated bicycle plot sprayer calibrated to deliver 18.5 gpa at 35 psi. Treatments were on May 24 and posttreatment samples were taken on May 27, 31 and jun 7, 14 and consisted of 10 sweeps of a standard net taken at random from each replicate. Conditions at treatment were calm, sunny and 78°F. No measurable precipitation occurred during study period.

Foliar Applications of Insecticides for Control of Biotype E Greenbugs on Grain Sorghum, 1985

Abstract This test was conducted at the University of Nebraska Field Laboratory, Mead, NE, in grain sorghum planted 25 May. Plots were 3 rows, 30 ft long. Treatments were replicated 4 times in a randomized complete block design. Insecticides were applied by a bicycle-wheeled plot sprayer at 40 psi and 29.3 gal/acre through a boom fitted with 1 top nozzle and 2 drop nozzles/row. The liquids were propelled with pressurized CO2. Insecticides were applied 23 Jul when plants were in the 10-leaf stage. The efficacy of each insecticide was evaluated by counting live greenbugs on 6 plants selected at random from the center row of each plot at 1, 7, and 14 days posttreatment. Rainfall during the sampling period was measurable in inches on 24 Jul (0.20), 30 Jul (0.50), and 5 Aug (0.40).

Chinch Bug Control, 1980

Abstract This experiment was conducted in Thayer County, NE. The plot area was bordered on 1 side by winter wheat. Sorghum was planted perpendicular to the wheat. Plots were 4 rows (spaced 0.9 m), 30.5 m long arranged in a randomized complete block design with 4 replications. The 2 center rows were used for insect and plant stand counts. In-furrow planting-time application of granules was made by directing the insecticide delivery tube from Noble metering devices into the planter shoe just behind the seed delivery tube. Banded planting-time application of granules was made by directing the granule delivery tube from Noble metering devices to in front of the planter press wheel through a 18-cm bander. Seed treatment was made by thoroughly mixing the insecticide with seed in a paper sack just before planting. Postemergence application of granules were applied over the plants with a Noble metering device mounted on a 2-wheeled carriage, manually operated. Postemergence application of liquid insecticides was made on 24 Jun with a compressed air plot sprayer mounted on a high-clearance ground sprayer. Plants were 7.6-10 cm tall. Drop nozzles were used so that plants and surrounding soil were thoroughly covered. Spraying systems TX-12 nozzle tips were used.

Alfalfa Seed, Insect Control, 1984

Abstract This test was conducted on a commercial field of seed alfalfa at Lovelock, NV. Spray treatments were applied with a field plot sprayer calibrated to apply 20.9 gpa at 35 psi to paired blocks of alfalfa 44 ft × 100 ft. Untreated blocks of the same size were located on each side of the treated blocks. Located in the center of the treated blocks was a leafcutting bee domicile which contained ca. 50 thousand nesting bees. Following cessation of pollinator activity treatments were applied late evening Jul 16. Three samples consisting of 10 sweeps each were taken from each treated and untreated block at 3, 7, and 14 days posttreatment. Night counts of nesting leafcutting bees were made pre- and posttreatment in the domiciles within the treated area and one outside the treatment area. Observations of bee activity and presence of dead bees were made in each domicile daily following treatment. Forging bees (both honey and leafcutting) were counted fore noon each day in yard wide transects across each treated and untreated block.

Sorghum Greenbug Control, 1980

Abstract These experiments were conducted at the University of Nebraska, South Central Research and Extension Center Farm, Clay Center, NE. Experiment 1 was arranged in a split block design with 10 replications; Experiments 2, 3, and 4 were arranged in a randomized complete block design with 5 replications. Plots were 4 rows (spaced 76-cm) 9.1 m long. The 2 center rows were used for insect counts and yield. In-furrow planting-time application of granules was made by directing the insecticide delivery tube from Noble metering devices into the planter shoe just behind the seed delivery tube. Banded planting-time application of granules was made by directing the granule delivery tube from Noble metering devices to in front of the planter press wheel through an 18-cm bander. Cultivation application of granules was made by directing the insecticide over the plants through the granule delivery tubes from Noble metering devices mounted on the cultivator. Foliar application of liquid insecticides was made with a compressed air plot sprayer mounted on a high-clearance ground sprayer. Drop nozzles were used so that plants received spray from the top and both sides

Foliar Insecticides for Hessian Fly Control in Morocco, 1985

Abstract Three postemergence-applied insecticides were evaluated at 3 different rates, to determine their potential for protecting wheat already infested with Hessian fly eggs. Insecticides were applied 13 Dec to durum wheat at the 2-leaf stage, growing on the SOGETA Farm, 3 km west of Settat, Morocco. Five to 10 unhatched fly eggs were present per plant, mostly on the first leaf. Treatments were applied with a CO2-powered, hand-carried plot sprayer, with flat-fan (8001) tips, calibrated to deliver 24 gpa at 40 psi. Plots were 1.8m by 10m, replicated 4 times in a RCB design. Air temperature at application was 21°C. Weather was sunny and warm for 14 days following treatment, followed by a cool, rainy period. Twenty days after treatment, 10 plants were sampled from each plot and evaluated for tiller number, total living larvae per plant, percent of tillers with living fly larvae, and percent of plants with living larvae.

Slug Control in No-Till Alfalfa, 1985

Abstract No-till alfalfa plots were located at Halme and Caldwell Fields, Ithaca, NY. These fields were treated with 2 lb Al/acre of glyphosate in Oct ’84 before seeding of alfalfa in the spring ’85. Alfalfa was seeded at 12 lb/acre with a John Deere Power Til drill with 8-inch row spacing, and fertilized with 300 lb/acre of 0-25-25 on May 22 and Jun 3 at Halme and Caldwell Fields, respectively. Plots were 6 × 20 ft with treatments replicated 6 times in a randomized complete block design. In each plot 2 holes, 4-inch diam × 6-inch deep, were excavated with a soil sampler and each covered with a 1 ft-square asphalt roofing shingle with aluminum foil glued to the top surface. These holes served as refuges for slugs and hence provided an efficient means of sampling. Sprays were applied with an air-activated bicycle plot sprayer calibrated to deliver 25 gpa at 40 psi, with 3 T-jet 8003 hollow cone nozzles. Molluscicidal baits were prepared by coating wettable powder on cracked corn with milk as a sticking agent. The prepared baits were applied evenly by hand at 20 lb/acre. Treatments were made on May 29 and Jun 14 during seedling emergence at Halme and Caldwell fields, respectively. Samples were taken by inspecting the holes for dead and live slugs at pretreatment, and at 1, 3, 7, and 14 days posttreatment. Alfalfa stands were visually rated on Jun 20. Three species of slugs were present, D. reticulatum being the major species.