CO2 Pressurized Backpack Sprayer Research Articles

Simulated herbicide spray retention of commonly managed invasive emergent aquatic macrophytes

AbstractInvasive emergent and floating macrophytes can have detrimental impacts on aquatic ecosystems. Management of these aquatic weeds frequently relies upon foliar application of aquatic herbicides. However, there is inherent variability of overspray (herbicide loss) for foliar applications into waters within and adjacent to the targeted treatment area. The spray retention (tracer dye captured) of four invasive broadleaf emergent species (water hyacinth, alligatorweed, creeping water primrose, and parrotfeather) and two emergent grass-like weeds (cattail and torpedograss) were evaluated. For all species, spray retention was simulated using foliar applications of rhodamine WT (RWT) dye as a herbicide surrogate under controlled mesocosm conditions. Spray retention of the broadleaf species was first evaluated using a CO2-pressurized spray chamber overtop dense vegetation growth or no plants (positive control) at a greenhouse (GH) scale. Broadleaf species and grass-like species were then evaluated in larger outdoor mesocosms (OM). These applications were made using a CO2-pressurized backpack sprayer. Evaluation metrics included species-wise canopy cover and height influence on in-water RWT concentration using image analysis and modeling techniques. Results indicated spray retention was greatest for water hyacinth (GH, 64.7 ± 7.4; OM, 76.1 ± 3.8). Spray retention values were similar among the three sprawling marginal species alligatorweed (GH, 37.5 ± 4.5; OM, 42 ± 5.7), creeping water primrose (GH, 54.9 ± 7.2; OM, 52.7 ± 5.7), and parrotfeather (GH, 48.2 ± 2.3; OM, 47.2 ± 3.5). Canopy cover and height were strongly correlated with spray retention for broadleaf species and less strongly correlated for grass-like species. Although torpedograss and cattail were similar in percent foliar coverage, they differed in percent spray retention (OM, 8.5± 2.3 and 28.9 ±4.1, respectively). The upright leaf architecture of the grass-like species likely influenced the lower spray retention values in comparison to the broadleaf species.

Peanut Response to Flumioxazin and S-Metolachlor Under High Moisture Conditions

ABSTRACT Georgia produces nearly 51% of the United States peanut (Arachis hypogaea L.) crop. To combat and prevent weed infestations, herbicide programs containing flumioxazin and S-metolachlor are often applied preemergence (PRE). Despite herbicide effectiveness for weed control, peanut injury following heavy rainfall can be problematic. The objective of this study was to evaluate the impact of injury from flumioxazin and S-metolachlor after simulated heavy rainfall events on peanut growth and yield. Plots were planted at the University of Georgia Ponder Research Farm located near Ty Ty, Georgia using conventional tillage practices and twin-row spacing. Treatments included PRE applications of flumioxazin at 0, 0.11 and 0.22 kg ai/ha alone or in combination with S-metolachlor at 0, 1.07, 1.40, 2.80 kg ai/ha and were applied using a CO2-pressurized backpack sprayer. Irrigation and rainfall were ≥20 cm in the 30 days after planting (DAP) to simulate heavy rainfalls. Flumioxazin at 0.22 kg ai/ha caused the greatest visual injury (>60%) and most whole-plant fresh weight/m reductions at 21 DAP compared to other treatments. Peanut density was not impacted by flumioxazin or S-metolachlor. Neither flumioxazin nor S-metolachlor affected J-rooting. Yield was not reduced by any rate of flumioxazin. However, S-metolachlor at 2.80 kg/ha, (2.6X field rate), reduced yields by 8.9% compared to plots where no S-metolachlor or recommended field rates were applied.

Spray Deposition on Weeds (Palmer Amaranth and Morningglory) from a Remotely Piloted Aerial Application System and Backpack Sprayer

This study was designed to determine whether a remotely piloted aerial application system (RPAAS) could be used in lieu of a backpack sprayer for post-emergence herbicide application. Consequent to this objective, a spray mixture of tap water and fluorescent dye was applied on Palmer amaranth and ivyleaf morningglory using an RPAAS at 18.7 and 37.4 L·ha−1 and a CO2-pressurized backpack sprayer at a 140 L·ha−1 spray application rate. Spray efficiency (the proportion of applied spray collected on an artificial sampler) for the RPAAS treatments was comparable to that for the backpack sprayer. Fluorescent spray droplet density was significantly higher on the adaxial surface for the backpack sprayer treatment than that for the RPAAS platforms. The percent of spray droplets on the abaxial surface for the RPAAS aircraft at 37.4 L·ha−1 was 4-fold greater than that for the backpack sprayer at 140 L·ha−1. The increased spray deposition on the abaxial leaf surfaces was likely caused by rotor downwash and wind turbulence generated by the RPAAS which caused leaf fluttering. This improved spray deposition may help increase the efficacy of contact herbicides. Test results indicated that RPAASs may be used for herbicide application in lieu of conventional backpack sprayers.

TRINEXAPAC-ETHYL AS CHEMICAL RIPENING AGENT ON SWEET SORGHUM CROP

Literary references on the quality of juice of sweet sorghum crop following chemical ripening agents spraying are rarely found up, mostly concerning to the trinexapac-ethyl. Accordingly, this article shares an unpublished content about chemically-induced physiological ripening on the sweet sorghum cv. CMSXS-646 by spraying trinexapac-ethyl before the crop flowering. A CO2-pressurized backpack sprayer, with flat spray nozzles, was employed to exogenously spray the plant growth inhibitor at 0.4, 0.8 and 1.6 l ha-1 on 90-days-old plants. Early after the crop harvesting, juice and lignocellulose samples were technologically assessed to total soluble solids, sucrose, purity, reducing sugars, total reducing sugars, fibers and yield of sugar. Sweet sorghum plants exposured to the trinexapacethyl at 0.4 and 0.8 l ha-1 produced juices with approximately 20.2 and 20.3 °Brix, 15.1 and 13.2% sucrose, 74.6 and 64.9% purity, as well as 107.7 and 98.2 kg t-1 sugar, respectively. Unlike, plants cultivated as control, juices with 21.0 °Brix, 16.0% sucrose, 76.9% purity and 118.0 kg t-1 sugar. Therefore, trinexapac-ethyl had suppressive effect on the quality of juice, mostly regarding to the total soluble solids and yield of sugar. Plants sprayed with trinexapac-ethyl at 1.6 l ha-1 developed the most fibrous stalks, as host-defense system response to stress induced on plant physiology. The conclusion is, therefore, that although does prejudices the quality of juice, making it unsustainable to the production of first-generation ethanol, trinexapac-ethyl as chemical ripening agent could lead the sweet sorghum cv. CMSXS-646, while lignocellulose renewable source, to the industrialization of cellulosic ethanol and bioelectricity.

Herbicides for Rooted Aquatic Macrophytes

ABSTRACT: The aim of this study was to evaluate the effectiveness of glyphosate, 2,4-D, and diquat to control the aquatic macrophytes Brachiaria subquadripara, Hedychium coronarium, and Myriophyllum aquaticum under greenhouse conditions. The following herbicides and doses were used: glyphosate at 240, 720, 1,680, 2,640, 3,600, and 4,320 g a.e. ha-1, 2,4-D at 335, 1,005, 1,675, 2,345, and 3,015 g a.e. ha-1, diquat at 100, 200, 300, 400, 500, and 600 g a.i. ha-1, and a control with 10 replications. Sprayings were applied with a CO2-pressurized backpack sprayer at a constant pressure of 172.36 KPa, tips DG 11002, and spray solution consumption of 200 L ha-1. The effectiveness of control was evaluated visually at 3, 7, 15, 21, 30, 45, and 60 days after application (DAA) and dry matter accumulation at 60 DAA. Glyphosate promoted the best effectiveness, with 100% control of B. subquadripara, with no dry matter accumulation from 720 g a.e. ha-1. The herbicide 2,4-D presented the best control for M. aquaticum with 100% control from 1,209 g a.e. ha-1, and for H. coronarium with 99% control from 2.015 g a.e. ha-1, both doses with no dry matter accumulation. The diquat was not effective in controlling the plants of M. aquaticum and B. subquadripara, besides allowing resprouts.

Fomesafen Crop Tolerance and Weed Control in Processing Tomato

Field experiments were conducted at the North Central Agricultural Research Station in Fremont, OH in 2009 and 2010 to evaluate the tolerance of tomato to fomesafen and the efficacy of this herbicide on weed control. The crop was machine-transplanted in June 5, 2009 and June 3, 2010. Herbicide treatments were applied using a CO2pressurized (276 kPa) backpack sprayer with 8002VS nozzle tips delivering 234 L ha−1. Pre-transplant (PRETP) treatments were applied on June 4, 2009, and May 27, 2010. Treatments included fomesafen at 280, 350, 420, 560, and 840 g ai ha−1. Minimal crop injury was observed 7 and 14 d after treatment (DAT) in plots treated with fomesafen at 840 g ha−1both years. None of the treatments caused crop injury either year at 42 DAT. Fomesafen at the highest rate provided acceptable annual grass, common purslane, and redroot pigweed control 42 DAT. Tomato yield was not reduced by the application of fomesafen. Registration of fomesafen herbicide would provide tomato growers an opportunity to control weeds caused by late emergence or poor initial control following a burndown herbicide application in tomato.

Evaluation of an Omri-Approved Spinosad Insecticide for Control of Cabbage Root Maggot in Direct-Seeded Root Crops, 2016*

Feeding by cabbage root maggot (CRM) larvae causes stunting and collapse of plants, and tunneling damage on root crops renders them unsaleable. We evaluated the OMRI-approved spinosad product, Entrust SC, as an in-furrow drench treatment at the time of seedling emergence alone or with a follow-up application one week following. These treatments were compared to an untreated check and to a furrow drench with the industry standard, chlorpyrifos, at the time of seeding. The experiment was conducted May–Jun 2016 at the University of Massachusetts Research and Education Farm in Deerfield, MA in a field with soil classified as Hadley silt loam. Soil was amended with 50 lb/acre urea (46-0-0) (N-P-K) and 20 tons/acre manure-based compost to increase attractiveness of the site to CRM flies for oviposition. Soil was harrowed twice and a roller was used to make a fine seedbed. An RCB design with four replications of each of the three treatments and an untreated check was used, with plots measuring 10 ft of bed length with three rows per bed. Weeds were controlled by hand and, due to very high pressure, flea beetles were controlled using a single application of Wrangler at 1.5 fl oz/acre on 23 Jun. ‘Hakurei’ turnips (Johnny’s Selected Seeds, ME) were direct-seeded on 10 May using a Jang TP1 precision seeder equipped with a Y-12 seed roller and a 9/14 gear setting to achieve 0.5-inch in-row and 12-inch between-row spacing. A border of untreated turnip plants was seeded around the perimeter of the experiment and between plots within the bed, to attract CRM flies. At-plant treatments were applied on 11 May using a CO2 pressurized backpack sprayer delivering 200 gpa at 30 psi through one TeeJet TP8002E nozzle to soak the soil in the seeding band, simulating an in-furrow application. The Entrust treatments were applied on 27 May and 8 Jun in the same manner, over the sprouted turnip plants. The total number of plants per plot was recorded weekly, on 26 May, and 3, 8, 15, and 22 Jun, and provided a measure of plant stand. Marketable yield was assessed on 15 and 26 Jun by harvesting 10 plants per plot at random and making visual estimations of root damage using the following criteria: a turnip root with >25% of the surface covered with shallow tunnels or with more than one deep tunnel or other deformation was considered unmarketable. All data were analyzed with SAS 9.4 using PROC GLM and means were separated using Fisher’s LSD (α = 0.05).

Evaluation of Selected Broadcast and Band-Applied Foliar Insecticides for Control of Thrips in Cotton, 2014: Table 1

Selected foliar insecticides, broadcast or band-applied, were evaluated for control of thrips in cotton. ‘DP 1028 B2RF’ cotton was planted 6 May at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA, using 36-inch row spacing. The foliar applications of Radiant, Orthene, Levo, and Exirel were made at the first true leaf stage on 22 May with a CO2-pressurized backpack sprayer, with Levo and Exirel applied again on 30 May. Radiant was tank-mixed with the crop oil concentrate, Agri-Dex. Aeris-treated seed was …

Efficacy of Organically Acceptable Insecticides AgainstDrosophila suzukii(Diptera: Drosophilidae) in Blueberries, 2014

The efficacy of two unregistered organically acceptable insecticides on SWD was assessed in June and July, 2014. The experiment was conducted at the Horticultural Crops Research Station near Castle Hayne, NC in a planting of rabbiteye blueberries, var. Premier. Treatments were replicated four times and arranged in an RCB design, blocked by rows, with a one-row buffer in between blocks. Plots consisted of five plants, 0.00415 acres, each. The following four treatments were compared: untreated control (UTC), Veratran D, Ecotec + TriTek, and Entrust SC (Table 1). Following label recommendations, Entrust was tank mixed with a nonionic surfactant, Dyne-Amic. Treatments were applied on 23 June using a CO2 pressurized backpack sprayer fitted with three solid cone nozzles (TeeJet TG 5 with medium size filter) calibrated to deliver a spray volume of 50 gpa at 45 psi pressure. Due to issues with the filter clogging during the Veratran D application, the following adjustments …

Efficacy of Insecticides AgainstDrosophila suzukii(Diptera: Drosophilidae) in Blueberries, 2014

The efficacy of formulation of malathion currently unregistered in blueberries, Atrapa, was compared with a standard malathion formulation and a recently registered material, Exirel for efficacy against SWD in May and June, 2014. Exirel treatments were compared with and without a surfactant. This experiment was conducted at the Horticultural Crops Research Station near Castle Hayne, NC in a planting of southern highbush blueberries, var. “Legacy.” Plots were 0.05 acres each and consisted of two rows of five plants. Treatments were replicated four times and arranged in an RCB design, blocked by rows, with a one-row untreated buffer in between blocks. Treatments (Table 1) were applied using a CO2 pressurized backpack sprayer fitted with three solid cone nozzles (TeeJet TG 5 with medium size filter) calibrated to deliver a spray volume of 50 gpa at 45 psi pressure. Both sides of a row were treated to ensure full plant …

SWEDE MIDGE CONTROL WITH INSECTICIDES ALLOWED FOR ORGANIC PRODUCTION, 2013

This trial was conducted to evaluate insecticides allowed for organic production. The trial was conducted on a field managed using practices allowed for organic production since 2008 at Cornell’s New York State Experiment Station in Geneva, NY. An overwintered red clover cover crop was plowed under in May. Broccoli (‘Belstar F1’) with 3-4 true leaves was transplanted on 17 Jun. The transplants were set by hand using a Water Wheel transplanter with a solution of 0.5oz/gal Fertrell fish oil emulsion into raised beds with 1.25 mil black polyethylene and drip irrigation. Annual ryegrass was seeded between the rows for weed control and mowed as needed. Five treatments and an untreated control were arranged in a RCB design with four replications. Each plot consisted of six plants spaced 12 inch apart with 7 ft between rows and 2 ft between treatments. Sprays (with the exception of Surround) were applied with a CO2 pressurized backpack sprayer at 40 psi delivering 40 gal/acre through two TeeJet 8002VS flat fan nozzles spaced 19 inch apart. Surround was applied to thoroughly cover the foliage, using a hand pump pressurized sprayer with a single nozzle. Treatments included Azera (pyrethrum plus azadirachtin) at 3.5 pt/acre, Ecotec (rosemary, peppermint, and wintergreen oils) at 4 pt/acre, Grandevo (Chromobacterium substugae strain PRAA4-1 and spent fermentation media) at 3 lb./acre, Surround (kaolin clay) at 0.5 lb./gal, Venerate (heat-killed Burkholderia sp.) at 2 gal/acre and an untreated control. Nu Film P was added to all treatments to improve spray adhesion. The first spray was applied 24 Jun. Five more sprays were applied on 2, 9, 16, 24, and 31 Jul. The last application occurred just before head formation. On 14 Aug plots were rated for damage using a visual damage rating scale (Hallett 2007), where 0 is no damage, 1 is mild twisting of stem or leaves and/or mild swelling of petioles, 2 is severe twisting of stem and/or crumpling of leaves and/or swelling of florets, and 3 is death of apical meristem and/or multiple compensatory shoots. Broccoli with a damage rating of 0 or 1 at harvest would be considered marketable. As heads matured between 14 and 27 Aug, they were measured (diameter) and harvested. Data were analyzed using the Kruskal-Wallis non-parametric test because of the qualitative nature of the damage rating data and the lack of fit to the normal distribution of the head formation data. Steel-Dwass All Pairs comparisons were conducted on damage ratings, head diameter, and head formation data to separate treatments (Table 1). Average maximum temperatures for 24-30 Jun, Jul, and 1-27 Aug, were 76.5, 79.9, and 75.4 F; average minimum temperatures were 59.2, 64.5, and 59.1 F. Rainfall amounts (inches) were 0.9, 4.8, and 4.1 for 24-30 Jun, Jul, and 1-27 Aug, respectively.

SQUASH VINE BORER CONTROL WITH INSECTICIDES ALLOWED FOR ORGANIC PRODUCTION, 2013

This trial was conducted to evaluate insecticides allowed for organic production. The trial was conducted on a commercial organic farm in Nedrow, NY with a documented squash vine borer population. ‘Dundoo’ zucchini seeds were sown into 50 cell flats in an organic mix on 17 May. Transplants were set by hand on 29 May in a field on 4 ft row centers, with a 6 ft wide access drive on one side. Transplants were irrigated twice with a Neptune’s fish Seaweed Blend at a rate of 1 oz/gal with a backpack sprayer to aid establishment. All plants were treated with Surround WP at a rate of 25 lb/acre at establishment and weekly for two weeks to prevent damage from striped cucumber beetle. Five treatments and an untreated control were arranged in a RCB design with three replications. Each plot consisted of five plants spaced 18 inches apart with 3 ft between treatments. Sprays were applied with a CO2 pressurized backpack sprayer at 40 psi delivering 40 gal/acre through two TeeJet 8002VS flat fan nozzles spaced 19 inches apart. Treatments included Agree WG (Bt aizawi) at 2 lb/acre, Entrust (spinosad) at 2.5 oz/acre, Javelin (Bt kurstaki) at 1.5 lb/acre, Mycotrol (Beauveria bassiana) at 1 qt/acre, Neemix 4.5 (azadirachtin) at 16 oz/acre, and an untreated check. The first spray was applied 1 Jul, four days after adult moths were first caught in pheromone traps. Two more sprays were applied on 11 and 18 July. On 8 Aug plants were evaluated for SVB infestation by examining the base of each for frass and tunneling damage. Data (% infested plants per plot) were analyzed by ANOVA and means separated using the Fisher’s LSD test.

CRUCIFER FLEA BEETLE CONTROL WITH INSECTICIDES ALLOWED FOR ORGANIC PRODUCTION, 2013

This trial was conducted to evaluate insecticides allowed for organic production. The trial was conducted on a field managed using practices allowed for organic production since 2008 at the New York State Experiment Station in Geneva, NY. An overwintered rapeseed cover crop was plowed under in May. Cabbage (‘Farao’) with 3-4 true leaves was transplanted on 23 May into raised beds with 1.25 mil black polyethylene and drip irrigation. Annual ryegrass was seeded between the rows for weed control. Four treatments and an untreated check were arranged in a RCB with four replications. Each plot consisted of five plants spaced 12 inches apart with 7 ft between rows and 2 ft between treatments. Sprays were applied with a CO2 pressurized backpack sprayer at 40 psi delivering 40 gpa through two TeeJet 8002VS flat fan nozzles spaced 19 inches apart. Treatments included Entrust (spinosad) at 25 oz/acre, Neemix 4.5 (azadirachtin) at 10 oz/acre, Pyganic 5.0 (pyrethrins) at 9 oz/acre, mixture of Neemix and Pyganic (10 and 9 oz/acre), and an untreated control. The first spray was applied 31 May as soon as beetles began invading the plots. Two more sprays were applied on 7 and 14 Jun. On 21 Jun plots were rated for damage using a 1-5 scale, with 1 being no damage and 5 being severe damage with plants nearly dead. Damage ratings were analyzed using the Kruskall-Wallis non-parametric test because of the qualitative nature of the data. Pair-wise Wilcoxon sign-ranked tests were carried out on damage ratings to separate treatments.

EVALUATION OF INSECTICIDES FOR CONTROL OF SOIL INSECT PESTS IN SWEET POTATOES, 2013

A field experiment was conducted at the LSU AgCenter Dean Lee Research Station in Alexandria, LA, to evaluate insecticides for management of sweetpotato soil insect pests, including BCB and SCB. In addition to an untreated check, three insecticide treatments were assessed in a RCB design with four blocks and one replicate per block. Plots were three rows wide (38-inch centers) and 35 ft long. A CO2-pressurized backpack sprayer calibrated to …

EVALUATION OF SELECTED FOLIAR INSECTICIDES FOR CONTROL OF STINK BUG IN SOYBEAN, 2012

Two tests were conducted to determine efficacy of foliar-applied insecticides against a stink bug complex in soybean. ‘USG 74B58’ soybean was planted on 10 May 2012 on a private farm in Goochland, VA, using 7.5-inch row spacing. A randomized complete block experimental design was used with 2 replicates; plots were 6 ft by 30 ft. Treatments in both tests were broadcast on 28 Aug with a CO2-pressurized backpack sprayer at 14.3 gpa and 18 psi through four 8002VS nozzles spaced 18-in apart on a 6-ft spray boom. Efficacy against the stink bug complex was determined at multiple days after treatment (DAT) by taking 15 sweeps/plot with a standard 15-in diameter sweep net and recording the number of nymphs and adults for BMSB, GSB, and BSB (totals for the species are reported). Data were analyzed using ANOVA and LSD statistical procedures.

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Selected insecticides applied as a liquid into the seed furrow at planting and foliar treatments were evaluated for control of thrips in cotton. ‘PHY 499 WRF’ cotton was planted 2 May at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA, using 36inch row spacing. Liquid in-furrow (IF) Admire Pro and Verimark treatments were applied into the seed furrow at 5 gpa using a microtube mounted between the disc openers, pressurized by CO2 at 51 psi. Foliar Benevia and Orthene treatments were broadcast at first true leaf stage (BC @ 1 tl) on 20 May with a CO2-pressurized backpack sprayer at 14.3 gpa and 16.8 psi through 8002VS nozzles spaced 18 inches apart on the spray boom. A RCBD was used with 4 replicates; plots were 4 rows by 35 ft. Thrips injury to plants was determined by visually rating injury using a 0 to 5 scale, where 0=no thrips induced plant injury, 1=10% injured leaves, no bud injury; 2=25% injured leaves, no bud injury; 3=75% injured leaves, and 0 to 25% buds injured; 4=90% injured leaves, and greater than 25% buds injured; and 5=dead plants. Thrips counts were taken from selected treatments on four dates by collecting five plants per plot in Mason jars containing approximately 500 ml soapy water. Thrips were counted under a stereoscope following suction filtration. Yield was determined by harvesting 2 rows of each plot (70 row ft) using a commercial 2-row cotton picker. Sub-samples were ginned to determine lint versus seed and trash weight (42.1% lint, 57.9% seed and trash). Data were analyzed using ANOVA and LSD statistical procedures.

Interaction of Imazapyr and a Brassinosteroid Analogue in Seedlings of <i>Eucalyptus grandis</i>

The application of brassinosteroids has been used to protect plants from environmental stresses. An experiment was carried out for the purpose of evaluating the interaction of the spirostanic analogue of castasterone (BB16) and the imazapyr herbicide by making use of seedlings clones of Eucalyptus grandis. It was used manual sprayers for the application of BB16, and for the herbicide application was used a CO2 pressurized backpack sprayer. The experiment was composed of six treatments: control; imazapyr (I) (0.750 kg ha-1 of active ingredient); BB16 in the concentrations of 0.08 (BB16(-)) and 0.16 mg L-1 (BB16(+)) applied immediately after the herbicide (I+BB16(-) and I+BB16(+), respectively) and, imazapyr applied immediately after the BB16 (BB16(-)+I and BB16(+)+I, respectively). At 18 days after the treatment application (DAT) it was verified that in the treatments I, BB16(-)+I and BB16(+)+I occurred total necrosis in terminal leaves of the apical branches. After 21 DAT, the treatment control, I+BB16(-) and I+BB16(+) expressed significative increments in height and stem diameter, in relation to other treatments. Similar behavior was verified to dry matter of the shoot and roots, at 35 DAT. When BB16 was applied before imazapyr, the deleterious effects on the variables dry matter of shoot, as well as in height and diameter of the seedlings, had been more significant than the isolated herbicide application. We found out that the application of analogue castasterona could act as a safener in seedlings of E. grandis submitted to the imazapyr action, when applied immediately after the herbicide, because these seedlings have not exhibited toxicity symptoms under this condition.

COMPARISON OF APPLICATION METHODS FOR TOBACCO BUDWORM CONTROL, 2010

Anthranilic diamide insecticides, two of which have recently been registered for use in tobacco, may be more persistent in plant tissue and move within leaf tissue to a great extent than other registered chemistries. These characteristics may allow anthranilic diamaide insecticides to be applied using different methods than standard materials used against TBW. Standard insecticide application methods for TBW control recommend a volume of 30 gpa water applied with 60 psi pressure using solid or hollow cone nozzles. Using one of the registered anthranilic diamaide insecticides registered in tobacco (Belt, Bayer CropScience) applied at a rate of 3.0 fl oz/acre, we compared 4 application volumes (5, 10, 20, and 50 gpa water) applied at 2 pressures (30 and 60 psi) to determine if applications at lower volumes and pressures were as effective as those at higher volumes with greater pressure. Greenhouse grown tobacco plants were transplanted on 4 May. Plants were treated with 0.8 fl oz/1000 plants Admire Pro 5 d prior to transplant to control early season tobacco flea beetle (Epitrix hirtipennis) and green peach aphid (Myzus persicae) populations. Four row plots, 50 ft in length, were established immediately after transplant. Plots were 0.018 acres each. Each treatment was replicated 4 times, and plots were arranged in an RCBD, blocked by replicate. Six wk after transplant, 10 plants each in rows 2 and 3 of each plot were infested with laboratory reared 2 instar TBW larvae, purchased as eggs from Chesapeake PERL (Savage, MD). Treatments were applied the d after larval infestation. Larval survival and leaf area consumed were rated 3, 7, and 14 d after foliar treatments were applied. Treatments were applied using a single nozzle boom fitted with a TG3 solid cone tip and powered by a CO2 pressurized backpack sprayer. Data were analyzed via Proc Mixed (SAS v. 9.1.3; Cary, NC) with replicate as a random variable. Each date was analyzed separately, not as a repeated measure.

EFFICACY OF FOLIAR INSECTICIDES FOR CONTROL OF SOYBEAN APHID IN MICHIGAN, 2005

Foliar insecticides were compared with an untreated check for SBA control at the Michigan State University, Saginaw Valley Bean and Beet Farm, Saginaw. Soybeans were planted in 30 inch rows on 5 May 2005, at a rate of 148,000 seeds per acre. Plots were 10’ × 25’ and treatments were replicated three times in a RCB design. Foliar treatments were applied using a CO2 pressurized backpack sprayer with twin jet nozzles at 40 psi and 23.8 gpa. Insecticide application timing was based on SBA surpassing the threshold of 250 SBA per plant (14 Jul). Pre-treatment whole-plant SBA counts were taken on 13 Jul, sampling 24 plants over the entire trial. SBA numbers averaged 830 SBA per plant at the R2 growth stage at this time. Whole-plant SBA counts, 5 plants per plot, were taken 4 (R3), 7 (R3), 14 (R4), and 21 (R4) DAT. Yield was taken with a Hage 125B small plot combine with a five foot grain head. All products were registered for use on soybeans in Michigan except Assail, Centric, Leverage and Trimax. Data were transformed prior to analyses by log10 (x + 1.0); untransformed data are presented. Data were analyzed using ANOVA and LSD (P = 0.05).

EVALUATION OF FOLIAR INSECTICIDES AND GAUCHO SEED TREATMENT UNDER LOW SOYBEAN APHID NUMBERS, MICHIGAN 2006

Foliar insecticides were compared with an untreated check and Gaucho seed treatment for SBA control and yield at the Michigan State University Entomology Farm, East Lansing, MI. The trial was a RCB design with four replications, planted on 1 Jun 06 in 10’ × 30’ plots at 117,000 seeds per acre. Gaucho was seed-applied at 2.0 oz/cwt before planting. Weekly whole-plant SBA counts and plant stages were taken before foliar treatment application beginning 16 Jun. No SBA were found prior to treating. Despite low aphid numbers, foliar insecticides were applied at the R3 growth stage on 21 Jul. This mimicked the practice of some growers to apply a ‘prophylactic’ treatment in anticipation of mid-season flights. Treatments were applied using a CO2 pressurized backpack sprayer with twin jet nozzles at 40 psi and 20 gpa. Whole-plant SBA counts and plant stages were taken on 5 plants per plot 7 and 19 DAT. Yield was taken with a Hage 125 combine with a five foot grain head. Data was analyzed using ANOVA and LSD (P = 0.05).