Untreated Rows Research Articles

Technology of soil treatment in the rows of plantings seedlings and seedlings of forest and horticultural crops

Analysis of the level of mechanization in the cultivation of soil in the planting of seedlings and seedlings of forest and garden crops necessary for the destruction of weeds, soil content in the loose state, making the root layer of the soil of nutrients, etc., revealed that inter-row processing has a 100% level. However, it remains untreated rows of plants that includes the protection zone, which requires to perform operations on rows in significant expenditures of manual labor, constituting 40...50 people/hour in 1 hectare. The optimum variant of technology of planting care of seedlings seedlings of forest and horticultural crops would be the conversion of cultivators KRN working body, allows to conduct processing of soil in the rows of plants. At the same time, operations of soil treatment are carried out both in row and row spacing. All known methods of tillage in a row require the use of special working bodies that provide loosening of the soil in a row and cutting weeds. Such working bodies should provide the necessary protective zone around the plants. The developed design of the working body is installed on the row cultivator KRN over the processed row, which provides one-time processing of row spacing and rows. The article presents the results of theoretical studies of a special working body.

Non-Target Impacts of an Attract-and-Kill Formulation Based on Plant Volatiles: Responses of some Generalist Predators.

Responses of non-target insects to a blend of plant volatiles used as components in an attract-and-kill formulation for Helicoverpa spp. (Lepidoptera: Noctuidae) were studied in an Australian cotton field. Two experiments, one involving suction sampling during the day and the other at night, were conducted. Rows that had been treated with the volatile blend, with no added insecticide, were sampled with a large suction sampler 18, 42, and 85h (day experiment) and 6, 30, and 78h (night experiment) after treatment. Rows located 5, 10, 20, and 300m away from the treated row were similarly sampled. Of seven generalist predators, only one accumulated on the treated rows compared to the untreated rows. Of the other six, five were found in lower numbers on the treated rows, and for one no significant effects were detected. Compared to pre-spray baseline levels, numbers of several taxa increased across the whole field after spraying, suggesting area-wide attraction, but localized responses to the treated rows were weak, and apparent repellence was more common than attraction. We suggest that attract-and-kill with plant volatiles should have minimal effects on populations of these predators, and is likely to be compatible with integrated pest management.

Acaricidal Control of Citrus Rust Mites, 2015: Table 1

Russetting of citrus fruit by citrus rust mite (CRM) can cause reductions in yield and quality. The present trial was conducted at the Southwest Florida Research and Education Center on 19-year-old ‘Valencia’ orange trees planted at 15 × 22 ft. spacing. An RCB design was used to assign four replications of each of seven treatments and an untreated check to 5-tree plots within rows separated by an untreated buffer row. Applications to both …

Organic Insecticides for Control of Asian Citrus Psyllid and Citrus Leafminer on Oranges, Fall 2014

ACP is the key pest of Florida citrus due to its role as vector of greening disease or “huanglongbing.” Feeding damage from CLM larvae facilitates spread of citrus canker caused by Xanthomonas axonopodis pv. citri . The present trial is a result of our recent effort to evaluate options for controlling these pests with organically approved insecticides. The experimental block located at a commercial grove near Labelle, FL, consisted of 12-yr-old “Hamlin” sweet orange planted at a density of 132 trees per acre. Eight treatments and an untreated check were randomly distributed in an RCBD with four replicates in five-tree plots over nine rows with one untreated buffer row between treated rows and one untreated buffer …

Comparison of Organic to Some Conventional Insecticides for Control of Asian Citrus Psyllid and Citrus Leafminer on Oranges, Spring 2014

ACP is the key pest of Florida citrus due to its role as vector of greening disease or “huanglongbing.” Feeding damage from CLM larvae facilitates spread of citrus canker caused by Xanthomonas axonopodis pv. citri . Organic citrus growers have few proven alternatives for controlling these pests, providing the motive for this trial. The experimental block located at a commercial grove near Labelle, FL, consisted of 12-yr-old “Hamlin” sweet orange planted at a density of 132 trees per acre. Ten treatments and an untreated check were randomly distributed in an RCBD with four replicates in five-tree plots over four rows with one untreated buffer row between treated rows and one untreated buffer tree between plots …

Olive fruit fly adult response to attract-and-kill bait stations in greenhouse cages with weathered bait spray and a commercial table olive orchard

Attract-and-kill bait stations and olive foliage sprayed with insecticidal bait spray and exposed to 0–4weeks of weather were evaluated for efficacy by olive fruit fly, Bactrocera oleae (Rossi), adult mortality. Mortality in greenhouse cage tests was significantly higher after three days than one day of exposure to non-weathered bait spray on bait stations and foliage, and on bait stations exposed to weather for three weeks. Mortality increased with an increase in insect exposure time, and decreased as bait spray weather exposure increased. Mortality was higher on bait stations than on olive foliage, and treated foliage showed little toxicity after 4weeks in weather. In a commercial orchard, bait station efficacy was determined by captures of adults on yellow panel traps. Day temperatures were slightly higher on the underside of the station than top from 2 May to 10 July, similar on the top and underside 11 July to 7 August, and slightly lower on the underside from 8 August to 4 September. Fruit length increased from 0.4 on 16 May to 3cm on 24 September and on 30 May attained 1cm, the minimum size to produce one adult. No larvae or adults emerged from collected fruit. More adults were captured in an untreated row than a row with bait stations until 22 August and significantly so for the period ending on 11 July. Maximum adult captures occurred during 2weeks prior to 19 September. Attract-and-kill bait stations would help reduce insecticidal applications and table olive production costs.

Intentional coverage gaps reduce cost of mating disruption for Phyllocnistis citrella (Lepidoptera: Gracillariidae) in citrus.

The leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a global pest of citrus and contributes to the incidence and severity of citrus bacterial canker. SPLAT CLM (ISCA Technologies, Riverside, CA) is an emulsified wax that provides sustained release of (Z,Z,E)-7,11,13-hexadecatrienal, the major component of P. citrella sex pheromone. Trials in commercial orchards demonstrated that SPLAT CLM applied to plots of varying width resulted in disruption of trap catch of male P. citrella within treated rows and across untreated rows adjacent to treated rows. SPLAT CLM applied to plots of constant width (10 rows) disrupted trap catch across an untreated gap as the square of the width of the gap. Similarly, the ability of the pheromone source in treated rows to disrupt trap catch across untreated gaps of constant size declined as the square of the width of adjacent treated areas. A coverage pattern of 4 rows skipped for every 10 treated rows resulted in a 4% reduction of trap shutdown, and reduced the product and application costs by 29%. Mining incidence by P. citrella in treated rows was reduced by 53% compared with untreated areas. Intentional coverage gaps can significantly reduce the cost of mating disruption. Commercial lures for P. citrella used in this study were highly potent with respect to attracting males. Each lure was approximately 10(3) times as attractive as an individual P. citrella female. Disruption of trap catch using commercial lures may underestimate actual mating disruption achieved in the field.

An applicator for high viscosity semiochemical products and intentional treatment gaps for mating disruption of Phyllocnistis citrella

AbstractThe leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a global pest of citrus, and contributes to the incidence and severity of citrus bacterial canker, Xanthomonas axonopodis pv. citri. SPLAT‐CLM™ (ISCA Technologies) is an emulsified wax product that provides sustained release of (Z,Z,E)‐7,11,13‐hexadecatrienal, the major component of the P. citrella sex pheromone. Here, we report success in development of a mechanized and automated applicator of SPLAT and other high viscosity products on a large scale in tree crops, and progress in optimization of coverage patterns to minimize the cost of disruption of P. citrella. The applicator (IFM‐5051; International Fly Masters) delivered 1 g dollops of SPLAT‐CLM into a citrus grove canopy within 2% of the targeted application rate. A field trial conducted in Florida (USA) demonstrated effective disruption (>90%) of male moth catch in traps baited with pheromone lures characterized by high potency following each of four applications of 250 or 500 g ha−1 of SPLAT‐CLM containing 0.15% (Z,Z,E)‐7,11,13‐hexadecatrienal. Catch of male moths in pheromone traps deployed as a transect across the border between treated and untreated plots was analyzed to describe the rate of loss of disruption as a function of distance from a treated area. The model was used to estimate a maximum gap of 65 m consisting of untreated rows bounded on both sides by treated rows that could be incorporated into coverage patterns without a significant loss of disruption. A second field trial was conducted to test the feasibility of leaving intentional coverage gaps. No difference in trap catch disruption was observed between plots uniformly treated with SPLAT‐CLM and plots where every fifth row (80% coverage) or every fifth and sixth rows (67% coverage) were left untreated. Incorporation of coverage gaps should be effective in reducing product use and overall cost of mating disruption for P. citrella in citrus and other species for which mating disruption occurs by a non‐competitive mechanism.

Effectiveness of Insecticides in Controlling the First and Second Generations of the Lobesia botrana (Lepidoptera: Tortricidae) in Table Grapes

The moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of table and wine grape (Vitis spp.) varieties in Cyprus. Many different insecticide combinations were applied for three consecutive years (2006-2008) in a Sultana seedless table grape vineyard, aimed at controlling the first and second generations of this pest under warm and dry Mediterranean climatic conditions. In Cyprus, Sultana is the main early maturing table grape variety grown in the country. L. botrana has two generations and a partial third on this export variety, of which the first two generations are the most destructive. Applications were made according to pheromone trap captures of males. One application was used against the first and two applications against the second generation of L. botrana. A high rate of bunch damage was observed in the untreated rows during all years, reaching 56.7, 62.5, and 69.2% in 2006, 2007, and 2008, respectively. Differences between insecticide treatments and the untreated control were statistically significant. The treatment combination of lufenuron, spinosad, and indoxacarb as well as the combination of chlorpyrifos, spinosa and indoxacarb, used against the first and second generations of L. botrana, were the most effective compared with the untreated control. Satisfactory control of the pest also was observed with other combinations such as lufenuron, cypermethrin, and Bacillus thuringiensis; chlorpyrifos, cypermethrin, and B. thuringiensis; and lufenuron, deltamethrin, and azadirachtin.

EFFICACY OF SPRAYS APPLIED AGAINST POWDERY MILDEW (ERYSIPHE NECATOR) DURING A CRITICAL PERIOD FOR INFECTIONS OF CLUSTERS OF GRAPEVINES (VITIS VINIFERA)

Erisyphe necator is one of the most destructive pathogens of grapevines and is normally controlled by seven and more fungicide treatments until veraison of grapes. Two fungicide regimes comprising either 3 or 7 sprays per season were compared in a German vineyard between 1999 and 2010. The trials always included: (i) 3 fungicide sprays, one before flowering, the second during blossoming and the third at berries diameter 2 mm [so called “Open Window Period” (OWP) sprays]; (ii) 7 sprays which included OWP sprays of (i) plus one spray before and three afterwards. The trials were carried out with a single line tunnel-sprayer in 4 replicates, each comprising 12 vines of highly susceptible varieties. Experimental rows were separated by untreated rows on both sides. Although in most years, natural initial inoculum was present, in 2008-2010, the initial inoculum was supplemented with artificial infections on the separating untreated spacer lines. Even under extreme disease pressure, 3 sprays in OWP had nearly the same and always more than 90% of the preventive effect of seven sprays.

TRAY DRENCH, TRANSPLANT WATER AND FOLIAR INSECTICIDE TREATMENTS FOR SUPPRESSING INSECT PESTS AND TOMATO SPOTTED WILT IN FLUE-CURED TOBACCO, 2010

The objective of the test was to determine the efficacy of selected insecticide application techniques for suppressing TSWV symptomatic plants and season-long suppression of TBW and THW population densities on flue-cured tobacco. The trial was conducted at the University of Georgia Bowen Research Farm in Tift County, Georgia. Plots were 3 rows wide (44-in row spacing) by 30 ft long and were separated on each side with an untreated border row and on each end with a fallow alley 6 ft wide. The experiment was designed in a RCB with 13 treatments and 3 replications. The tobacco was transplanted on 14 April into Tift sandy loam soil at a rate of 7000 transplants per acre. A pre-plant application of Prowl and Spartan herbicides and Lorsban Advanced insecticide (for soil insect pest control) was applied several days prior to transplanting. No other pesticides were applied except the selected insecticide treatment options evaluated in this study. The plots were irrigated twice during the season. Plots were periodically inspected for insect pest infestation throughout the season by observing each plant (54 plants per plot) for live insects. The plots were observed weekly for symptomatic TSWV plants, a disease that is vectored by certain thrips species. Forty-eight hours prior to transplanting, five insecticide treatments were applied as tray drench treatments (TD) in the greenhouse using 6.7 oz of water per 242 cell tray and then rinsed off the foliage and into the root zone with water. Four additional insecticide treatments were applied in the transplant water (TPW) in 2 oz of water per transplant (109 gpa). On 18 May and 3 Jun, three foliar insecticide treatments were applied using a CO2 pressurized sprayer with 3 TX-12 nozzles down a single row delivering 22.8 gpa at 40 psi. All plants in each plot (54 plants per plot) were sampled weekly for TSWV symptomatic plants and on 18 and 25 May and 1, 10, and 15 June for TBW and THW densities. The TSWV and insect count data were subjected to ANOVA and means were separated using the Waller-Duncan Kratio t Test at P = 0.05.

실행방식 측면에서 살충제의 신중한 사용에 의한 저항성 발달의 관리

해충의 저항성발달로 야기되는 문제를 해결하기 위한 정보를 제공함으로써 향후연구를 촉진시키고자 하였다. 농약사용이 지속되는 한 저항성 발달은 필연적이라는 생각으로, 저항성발달을 지연시키기 위해 재배자가 활용할 수 있는 약제성질에 근거를 둔 약종선택, 혼용, 교호, 모자이크 처리 등 약제살포법과, 천적과 양립할 수 있는 선택성 살충제와 저항성 천적의 이용을 중심으로 한 병해충 종합관리(IPM)에 대해 고찰하였다. 저항성관리에 약종의 성질을 이용할 경우 약종별로 작용점과 mode of action(작용방식)이 같거나 다를 수 있고, 2차 해충과 함께 살충제의 활성, 잔류기간, 약제 저항성 발달에 대한 취약성도 다르다. 약제는 섭식, locomotion(거동), 비행, 교미, 포식자 회피 등에도 영향을 미치므로 종합적으로 고려하여 역교차저항성을 나타내는 살충제의 사용이 바람직하다. 농약혼용은 실제 많이 이루어지고 있고 앞으로도 그러하겠지만, 진정한 의미에서 저항성 발달 지연을 위한 혼용, 교호, 모자이크 처리법은 대립유전자의 우성도, 교차저항성, 유입(immigration), fitness 불이익 등과 함께 살충제의 작용방식과 작용점들의 차이에서 구성약제가 매우 높은 비율로 충을 죽이는 부의 교차저항성을 가진 살충제들의 채택에 대하여 논의하였다. 저항성 관리에 약제혼용의 대표적인 사례 22가지와 교호처리 사례 27가지를 표로 제시하였다. 혼용처리의 잠재적 불이익은 생물적 방제의 와해, 이차해충의 저항성발달, 고도의 저항성 개체군 선발, 다양한 살충제에 대한 교차저항성 범위 확대를 내포하고 있다. 교호처리는 살포약량을 높이거나 낮추고, 다른 대사기구를 가진 살충제를 사용하는 것도 고려되었다. 모자이크 처리는 진딧물 같이 정주성 해충인 경우에 연관없는 살충제를 교호로 다른 구역에 처리하거나, 살충제 처리한 열(列)과 그렇지 않은 것을 혼합 배치하여 저항성 발달을 지연시키거나 피해를 감소시킬 수 있다. 해충의 저항성 진화 측면에서 볼 때, 기생자와 포식자의 저항성과 선택성은 농약처리를 요하는 세대 수를 감소시키고 농약으로부터 피난처의 상보적 역할을 수행할 수 있다. 작물별, 기주별, 기생자와 포식자에게 선택성을 보이는 약제를 별도의 표로 요약하여 제시하였다. 기생자의 생존력 향상을 위해 살충제의 선택성과 선택성에 영향을 주는 내 외적 요인에 대하여 검토하였다. 농약사용 하에서 기생자를 사용하기 위해 농약에 대해 저항성이거나 내성이 있는 기생자를 검정, 채집 혹은 선발하는 것을 논의하였다. 포식자에 대한 선택독성에 영향을 미치는 요인들로 농약의 선택성, 선택성의 포장적용과 그에 미치는 요인, 포식자와 기주의 균형, 선택성을 도외시한 방제법의 문제점, 천적과 농약의 양립성 등에 대하여 논의하였다. An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

EVALUATION OF SELECTED INSECTICIDES FOR CONTROL OF BOLLWORM (BW) AND TOBACCO BUDWORM (TBW) IN GEORGIA ON COTTON, 2004

This test was conducted at the Southeastern Research and Education Center, Midville, GA. The test was set up in a RCB design with 4 replications and one untreated check per replication. The plots were 4 rows by 50 ft with an untreated border row on each side. The rows were planted on beds spaced 38 inches apart using a 4-row Max Emerge II John Deere planter. Temik 15G at 3.0 lb product/acre was placed in-furrow at planting for early season thrips control. Treatment applications began on 14 Jul when square damage was approaching a threshold of 5%. Treatments were applied with a CO2 spraying system mounted on a Powell high cycle sprayer. The sprayer traveled at a speed of 3.0 mph. Treatments were applied at a volume rate of 10 gpa, at 50 psi, with 3 nozzles per row using TX-3 hollow cone nozzles. Treatments were applied on 14, 20, 27 Jul, and 4 Aug. Weekly efficacy evaluations were done by randomly selecting 5 plants from the middle two rows of each plot and counting all the fruiting structures (squares and bolls) on the upper third of each plant. Fruiting structures were examined for feeding damage and the presence of larvae. The efficacy surveys were done on 20, 27 Jul, 4, and 11 Aug. On 5 Oct, yield was taken by mechanically harvesting the two middle rows of each plot. Means for percent square damage and yield were analyzed using ANOVA with means separation using LSD (P ≤ 0.05).

EVALUATION OF INSECTICIDES FOR CONTROL OF INSECT PESTS IN SWEET CORN, 2001

Sweet corn was planted on 12 Jun at the Eastern Shore Agricultural Research and Extension Center near Painter, VA. Each plot consisted of two 20-ft long rows spaced 3 ft apart. Plots were flanked by at least one untreated row. The experiment included nine treatments and an untreated check arranged in an RCB design replicated six times. Insecticide applications were made on 26 and 29 Jul; 1, 4, and 7 Aug using a propanepressurized backpack sprayer that had a boom equipped with a single hollow cone nozzle calibrated to deliver 30 gpa at 40 psi. Latron B-1956 was added to all treatments at 8 fl oz/product/100 gal water. Timing of the first application corresponded with the initiation of the silk stage (approximately 50% silk). On 10 Aug, 40 mature ears were harvested per plot and examined for damage by Lepidopteran larvae and SB. Ear quality was rated as either fresh market (no damage), processing (no damage or damage confined within the first 1.5 inches from the tip of the ear) or cull (any damage below the first 1.5 inches from the tip of the ear). The number of CEW, ECB, FAW, SB larvae and SB adults per ear was recorded. Data were analyzed using ANOVA and treatment means were compared among each other using LSD at P < 0.05.

EVALUATION OF INSECTICIDES FOR CONTROLLING INSECT PESTS IN SWEET CORN, 2000

Sweet corn was planted on 12 Jun at the Eastern Shore Agricultural Research and Extension Center near Painter, VA. Each plot consisted of two 20-ft long rows spaced 3 ft apart. Plots were flanked by at least one untreated row. The experiment included nine treatments and an untreated check arranged in an RCB design replicated six times. Insecticide applications were made on 26 and 29 Jul; 1, 4, and 7 Aug using a propanepressurized backpack sprayer that had a boom equipped with a single hollow cone nozzle calibrated to deliver 30 gpa at 40 psi. Latron B-1956 was added to all treatments at 8 fl oz/product/100 gal water. Timing of the first application corresponded with the initiation of the silk stage (approximately 50% silk). On 10 Aug, 40 mature ears were harvested per plot and examined for damage by Lepidopteran larvae and SB. Ear quality was rated as either fresh market (no damage), processing (no damage or damage confined within the first 1.5 inches from the tip of the ear) or cull (any damage below the first 1.5 inches from the tip of the ear). The number of CEW, ECB, FAW, SB larvae and SB adults per ear was recorded. Data were analyzed using ANOVA and treatment means were compared among each other using LSD at P < 0.05.

COMPARISON OF SOIL INSECTICIDE APPLICATION METHODS IN A CONSERVATION TILLAGE SYSTEM FOR CONTROLLING CORN WIREWORMS ON FIELD CORN, 1999

COMPARISON OF SOIL INSECTICIDE APPLICATION METHODS IN A CONSERVATION TILLAGE SYSTEM FOR CONTROLLING CORN WIREWORMS ON FIELD CORN, 1999: This study was conducted at the Mountain Branch Experiment Station, Blairsville, GA, to evaluate the efficacy of various methods of applying soil insecticides for the control of corn wireworms. Each treatment was applied to the two middle rows of 25-ft long, 4-row plots. A RCB design with four replications was used. One untreated check was included in each replication. Seed was planted on 19 May using a four row Cole no-till planter. Granular insecticides were applied at planting using three methods: a 7-inch band application, a 7-inch T-band application, and precision placement of insecticide onto the planted hill using a jab planter for seed placement and a bazooka for insecticide application. All insecticide rates are specified as lb (AI)/acre based on 38-inch rows. On 4 Jun, 20 plants were selected at random in untreated rows and examined for insect injury and the presence of larvae. All plants had wireworm injury and 7 plants had late instar corn wireworm larvae present in the soil nearby. On 8 Jun, 26 Jun, and 19 Jul, wireworm plant damage ratings were assessed for wireworm damage by surveying all of the plants in the two middle rows of each plot for feeding holes, tillered plants, and severely stunted plants. The total number of damaged and undamaged plants was recorded. The middle two rows of each plot were mechanically harvested on 26 Oct using a Hage small plot one row combine. Whole kernel corn was weighed in lb in the field to determine yield.

EVALUATION OF FOLIAR PRODUCTS FOR CONTROLLING INSECT PESTS OF SNAP BEAN, 1999

EVALUATION OF FOLIAR PRODUCTS FOR CONTROLLING INSECT PESTS OF SNAP BEAN, 1999: Snap beans were planted on 7 Aug at the Eastern Shore Agricultural Research and Extension Center near Painter, VA. Each plot consisted of two 20-ft long rows spaced 3 ft apart. Plots were flanked by two untreated rows. The experiment had 7 treatments and an untreated check arranged in a RCBD replicated six times. The standard treatment included an initial application of Orthene 75S followed by weekly applications of Capture 2EC. Insecticide applications were made on 13, 20, 27 Sep and 4 Oct using a propane-pressurized backpack sprayer that had a boom equipped with a 3 hollow cone nozzles calibrated to deliver 30 gal of spray/acre at 40 psi. One nozzle was oriented over the top of the row and two were on drops pointing to the sides of the row. The first foliar application was timed to correspond with the initiation of the bloom stage and detection of 5 or more ECB moths per night using a black light trap. On 8 Oct, 100 mature pods were randomly sampled from each plot and inspected for worm (CEW + ECB) and BLB injury. Data were analyzed using the analysis of variance procedure PROC GLM of SAS and treatment means were compared among each other using LSD at P < 0.05. Means were transformed by a log10 (x + 1) function before analysis; however, untransformed means are presented.

EFFECT OF APPLICATION METHOD, RATE, AND IRRIGATION ON IMIDACLOPRID EFFICACY AGAINST APHIDS IN SHADE TOBACCO, 1998

EFFECT OF APPLICATION METHOD, RATE, AND IRRIGATION ON IMIDACLOPRID EFFICACY AGAINST APHIDS IN SHADE TOBACCO, 1998: Admire 2F (imidacloprid) application methods, rates and the effects of irrigation were evaluated for tobacco aphid control in a cloth-covered shade tent at the CT Agricultural Expt. Station Valley Laboratory in Windsor, CT. Admire 2F was applied at 0.17 or 0.34 lb (AI)/acre (1 or 2 oz per 1000 plants based on 10,800 plants/acre) for all treatments. The soil was an Entic Haplorthod (71.8% sand, 23.0% silt, 5.2% clay, pH = 6.0 and OM = 4.0%). On 26 May, plots were fertilized with 110 lb N/acre of cottonseed meal-based 10-8-10, plots were broadcast with Lorsban 4E at 1.5 lb (AI)/acre and Ridomil 2E at 1 lb (AI)/acre and spiked to incorporate. On 3 Jun, preplant Admire 2F in 100 gpa was broadcast to appropriate plots in a 39-inch swath using a TeeJet 8004E nozzle at 18 to 20 psi and spiked. Tobacco was transplanted on 27 May to rows 39-inch apart with a 1-ft spacing within rows. There were 5 replicates of single-row plots of each treatment. Every 3rd row was an untreated border row. Plots were irrigated 27 May with 0.25 inches water. Admire 2F was applied on 29 May as a soil drench using a backpack sprayer with a TeeJet TG-3 nozzle at 15 psi to apply 20 ml/plant in 2 10-ml applications 2-cm to two sides of each plant. Plots were sidedressed with 70 lb N/acre of cottonseed meal-based 10-8-10 and cultivated on 18 Jun. Admire 2F was band applied at the last cultivation on 23 Jun in 70 gal water/acre to appropriate plots (with 83 lb N/acre) to 6 inches on either side of rows using a backpack sprayer with a TeeJet 8004-E nozzle and incorporated by mechanical cultivation and hoeing. Appropriate plots were irrigated with 0.5 in water. One leaf each from 10 plants per row was removed on 30 Jul, 4 Aug, 17 Aug, 27 Aug, and 3 Sep, and rated for apterous tobacco aphids (scale: 0 = no aphids or winged only; 1 = 1 aphid per leaf; 2 = 2-10 aphids 3 = 11-100 aphids and 4 = more than 100 aphids per leaf). Treatments were compared within dates by the nonparametric Kruskal-Wallis Test and the multiple comparison Z-Test.

Use of Imidacloprid- Treated Row Mixtures for Colorado Potato Beetle (Coleoptera: Chrysomelidae) Management

The ‘high dose’ strategy of applying imidacloprid as an ‘at-planting’ soil treatment uniformly throughout a potato field may result in rapid pest adaptation, as it has for other systemic insecticides. Alternatively, treated and untreated plants in a field provide a refuge to pests so that some portion of the population is not subjected to selection. In 1993- and 1994-field experiments involving potato cultivars with contrasting maturity periods, plots of mixtures of imidacloprid-treated and untreated rows were compared with plots of untreated and 100%treated rows to determine their effects on the Colorado potato beetle, Leptinotarsa decemlineata (Say). First-generation populations and feeding injury were significantly reduced by mixtures of imidacloprid treated rows, when post-diapause adults were released along the edge of plots to simulate a typical colonization pattern. Densities of life stages and percentage defoliation decreased as the proportion of imidacloprid-treated rows increased. The effectiveness of imidacloprid was greater than the additive effect based on the proportional contribution of the treated rows. Beetle populations decreased as the distance increased inward from the outer rows, because invading beetles were increasingly suppressed as they encountered rows of imidacloprid-treated plants. This suggests that the treated rows at the edge of the field in a row mixture acted as a toxic barrier to colonizing beetles. Even when colonizing adults were introduced uniformly in row mixture plots, the treated rows trapped many dispersing adults and suppressed feeding injury on adjacent untreated rows. Mixtures of treated and untreated rows deployed alone or in combination with a perimeter treatment are discussed as ways to reduce the amount and cost of insecticide used, create refuges to minimize resistance development, and reduce environmental risks.

Evaluation of Insecticides for Control of Aphids on Nucotn 33B Cotton, 1997

Abstract Insecticides were evaluated at North Mississippi Research and Extension Center, Verona, MS, in a RCB design with 4 replications. Plot size as 4 rows wide (38-inch row spacing) by 50 ft long with 4 untreated rows between plots and a 10-ft planted buffer at the end of each plot. Insecticides were applied on 11 Jul with a high-clearance spray tractor equipped with two Spraying Systems TX4 hollow-cone nozzles per row and calibrated to deliver 10 gpa at 40 psi at 3 mph. Carrier of the in-secticide was water. Samples were taken from 10 leaves per plot at each of two levels on the plant: upper (first fully expanded leaf), and mid (mainstem leaf located one-third down the plant), aphids were counted on the underside of each leaf. Yield (lb of seed cotton per acre) was determined by mechani-cally harvesting the center two rows of each plot, and measuring the actual area picked.