Handgun Applications Research Articles

Curative Control of the Peachtree Borer Using Entomopathogenic Nematodes.

The peachtree borer, Synanthedon exitiosa (Say 1823), is a major pest of stone fruit trees in North America. Current management relies upon preventative control using broad-spectrum chemical insecticides, primarily chlorpyrifos, applied in the late summer or early fall. However, due to missed applications, poor application timing, or other factors, high levels of S. exitiosa infestation may still occur and persist through the following spring. Curative treatments applied in the spring to established infestations would limit damage to the tree and prevent the next generation of S. exitiosa from emerging within the orchard. However, such curative measures for control of S. exitiosa do not exist. Our objective was to measure the efficacy of the entomopathogenic nematode, Steinernema carpocapsae, as a curative control for existing infestations of S. exitiosa. In peach orchards, spring applications of S. carpocapsae (obtained from a commercial source) were made to infested trees and compared with chlorpyrifos and a water-only control in 2014 and 2015. Additionally, types of spray equipment were compared: nematodes were applied via boom sprayer, handgun, or trunk sprayer. To control for effects of application method or nematode source, in vivo laboratory-grown S. carpocapsae, applied using a watering can, was also included. Treatment effects were assessed 39 d (2014) or 19 d (2015) later by measuring percentage of trees still infested, and also number of surviving S. exitiosa larvae per tree. Results indicated that S. carpocapsae provided significant curative control (e.g., >80% corrected control for the handgun application). In contrast, chlorpyrifos failed to reduce S. exitiosa infestations or number of surviving larvae. In most comparisons, no effect of nematode application method was detected; in one assessment, only the handgun and watering can methods reduced infestation. In conclusion, our study indicates that S. carpocapsae may be used as an effective curative measure for S. exitiosa infestations.

Evaluation of Handgun and Broadcast Systems for Spray Deposition in Greenhouse Poinsettia Canopies

Handgun applicators are popular, general-purpose greenhouse sprayers. However, there are few recommendations on how to use them to treat plant benches. Handgun applications made from one side can result in significant differences in deposits between the side of the plant facing the spray stream and the opposite side. Broadcast spraying over the top of the canopy may improve spray distribution across the canopy. The objective of this research was to determine differences in performance between different sprayers used to treat mature poinsettias and differences in the fate of the spray within the canopy with the aim to determine which techniques produced the highest spray retention on the abaxial leaf surface. A benchtop trial was conducted using a mature poinsettia canopy in a greenhouse. Sprayer treatments were used to apply tank mixes of pesticides and fluorescent tracer. Nylon screen targets were secured to the abaxial surfaces of leaves in the upper and lower parts of the canopy. Benchtop trials revealed significant differences between the amount of spray found on the upper and lower canopy target areas. Handgun nozzle pressure was a more significant factor in depositing material on the abaxial surfaces of leaves than changing application rate. A TwinJet boom system using dual-orifice nozzles did not treat abaxial surfaces differently from the handgun applications. The air-assist treatment with flat-fan nozzles produced the highest mean deposits on abaxial surfaces in the lower canopy area, but overall there were no statistical differences in lower canopy deposits between treatments. These results demonstrate the difficulty that ornamental producers have in targeting pesticide placement on abaxial leaf surfaces deeper in the canopy. The variability in spray deposits observed on foliage demonstrates the potential for significant variability in pest management.

Preharvest Lipophilic Coatings Reduce Lenticel Breakdown Disorder in ‘Gala’ Apples

Lenticel breakdown disorder (LB), most prevalent on ‘Gala’ (Malus × domestica) apples, especially in arid regions, has also been observed on other common cultivars. Depending on the preharvest environment, fruit maturity, and length of storage, LB usually appears as one or more round, darkened pits, centered on a lenticel, ranging in diameter from 1 to 8 mm. Symptoms are not visible at harvest nor are they usually apparent on unprocessed fruit after storage. However, following typical fruit processing and packing, symptoms are fully expressed after 12 to 48 h. Because the 3 to 4 weeks preceding ‘Gala’ harvest are usually the hottest and least humid, we theorized that desiccation stress was a main causative factor. Thus, several unique lipophilic formulations were developed that might reduce desiccation potential during this period of hot arid weather and rapid fruit enlargement. Emulsions of lipophilic formulations were applied to whole trees at various dosages and timings. In 2005, using a single handgun application 1 day before harvest, the best treatment reduced LB by about 20% in fruit stored 90 days at −1 °C. The following season, the best treatment from a single handgun application 7 days before harvest reduced LB by 35% after 90 days at −1 °C, whereas 3 weekly applications beginning 3 weeks before harvest reduced LB in similarly stored fruit by as much as 70%. In 2007, the best single treatment applied 1 week before harvest using a commercial airblast sprayer reduced LB by almost 50% after 90 days at −1 °C.

Comparing Greenhouse Handgun Delivery to Poinsettias by Spray Volume and Quality

Insecticide and fungicide labels often lack specific recommendations on the spray volume and spray droplet sizes that will provide the most efficacious pest management of ornamental pest problems. A greenhouse trial was established to determine differences in spray retention in a poinsettia canopy between single-nozzle, handgun applications made using three different spray volumes and three different spray qualities. For the same areas of the canopy, there were few differences in spray deposit between treatments. Canopy position was a significant factor in the amount of spray found on foliar and artificial targets. Higher deposits were measured in the fronts and upper areas of the canopy than the backs and lower areas of the canopy. There were no significant differences in recovery of fungicide from leaves between treatments. The high-volume application produced the highest deposits on artificial targets across all spray qualities. There were no significant differences in overall spray deposit between the low- and medium-volume treatments.

Control of Codling Moth, Cydia pomonella (Lepidoptera: Tortricidae), with Steinernema carpocapsae: Effects of Supplemental Wetting and Pupation Site on Infection Rate

Abstract Infection of cocooned codling moth ( cydia pomonella ) larvae by the entomopathogenic nematode Steinernema carpocapsae was studied in three field experiments. Factors that varied within or between experiments included method of application, type of substrate containing cocooned larvae, time when nematodes were applied, seasonal effects, and supplemental wetting before or after nematode application. Conventional air-blast sprayer applications of 0.5–5.0 million infective juveniles (IJs)/tree in fall resulted in ca. 30% mortality of larvae in cardboard trap bands, whereas hand-gun application (2 million IJs/tree) produced mortality of ca. 70%. Application in the evening caused higher larval mortality than application in the morning when no supplemental wetting was used after treatments. Morning and evening applications caused equivalent larval mortality when a postwetting treatment was included. In a trial conducted in midsummer, supplemental wetting, either before or after hand-gun application of 1 million IJs/tree, enhanced nematode-produced mortality. Mortality approached 100% if both pre- and postwetting was used. Larvae in exposed cocoons on apple wood were infected at a higher rate (86%) than those on wood in less exposed positions (73%) or in nonperforated cardboard (72%). Mortality rates for larvae in perforated cardboard were intermediate (77%). Application volumes used to deliver nematodes slightly enhanced infection rate of larvae in some substrates but not others. In one trial, parasitism of codling moth by the wasp Mastrus ridibundus (Ichneumonidae) was negatively correlated with nematode infection of codling moth larvae. Dissections showed that ca. 10% of larvae infected by nematodes had been attacked by the wasp.

Including Domestic Violence Restraining Orders in Brady Bill Background Checks: The Alaska Experience

Alaska has recently implemented major changes in its ability to capture when a domestic violence restraining order has been issued and in its ability to make this information available to the authorities for the purposes of Brady Bill handgun application background checks. Curiously, as the number of cases of domestic violence has increased dramatically, the number of handgun applications has decreased sharply. The article follows these events of recent years and points out the problems faced by policy makers in trying to understand the impact of the changes on future incidents of domestic violence.

Vegetation Management along Transmission Utility Lines in the United States and Canada

A survey investigating vegetation control methods along transmission rights-of-way was sent to 220 Utility Arborist Association companies. The survey contained questions regarding right-of-way characteristics, control methods used, total dollars spent on vegetation management, and priorities of the vegetation management program. The ROW area reported represented over 48% of all the investor-owned ROWs over 39 Kv in service throughout the United States. More than 75% of the respondents reported using herbicides on their rights-of-way. However, acres treated mechanically outnumbered those treated chemically by a margin of 2.7:1. Garlon 3A and Garlon 4 topped all herbicides, with a combined 220,574 projected gal (834,961 L) of the estimated 549,869 gal (2,081,474 L) of herbicide applied to transmission rightsof- way in 1995. It appears that quite low levels of active ingredients are being applied per acre. Basal, high-volume foliar, and low-volume foliar with a backpack or handgun applications accounted for approximately 75% of the acres of transmission ROWs treated with herbicides.

BAS-125, A Promising Vegetative Growth Control Chemical for Bearing Apples

Handgun applications on bearing spur `Red Delicious' evaluated both timing and concentration. At season's end, single 250-ppm applications at petal fall (PF), PF+7, +14 or +21 days reduced growth by 47% to 67%. Concentration of 125, 250, and 375 ppm @ PF+7 were all effective (45% to 55% reduction). Number of pruning cuts, pruning weight, and pruning time were all reduced. Applications at PF+0, +7 and +14 days increased fruit set, and, as a result, fruit weight trended lower. Airblast applications to `Top Red Delicious' applied at PF+3 weeks using 125, 250, and 500 ppm showed good initial growth suppression, but considerable regrowth in August and September. Yet, pruning weight and tree row volume were reduced with no fruit set or quality differences. Multiple, low-rate applications starting at PF on `Granny Smith' were very effective (60-70% reduction). Total application concentrations of 250 ppm were more effective than 500 ppm. The earlier the application sequence was started, the better the growth suppression. Two years of successive 200-ppm applications to the same trees in five separate plots involving three varieties showed an average 32% reduction in year 1 and a 56% reduction in year 2.

Absorption and Translaminar Activity of Abamectin in Apple and Pear Foliage as Determined by Spider Mite (Acari: Tetranychidae) Mortality

Translaminar activity of abamectin was studied during 1992-1994 on apple. Malus X domestica Borkhauser, and pear, Pyrus communis L. Field-aged residues were bioassayed from the top or bottom leaf surface of apple and pear after atomizer application to the top or bottom surface, or handgun application to both surfaces. Tetranychus urticae Koch was used as the test organism with the exception of 1 experiment, which included Panonychus ulmi (Koch). Abamectin showed little translaminar activity on apple regardless of the leaf surface to which it was applied. There was preferential absorption by the bottom leaf surface, which resulted in higher levels of mortality for mites feeding on the bottom surface when this was also the treated surface (bottom/bottom [surface treated/surface assayed]). Mortality caused by other combinations (bottom/top, top/bottom, top/top) was minimal. Mortality from assays conducted on the bottom surface was also higher in the apple/handgun experiments. Translaminar activity was greater on pear, but primarily through the bottom leaf surface. The degree of translaminar movement was sufficient to cause comparable levels of mortality on both the top and bottom surfaces when applied solely to the bottom surface. There was no difference in mortality between the 2 mite species when assayed on the same leaf surface. However, based on control mortality and runoff, the bottom leaf surface of apple and pear is a more favorable habitat for T urticae than the top surface, whereas the opposite is true for P ulmi. The implications of mite host preference, feeding behavior, and differential absorption of abamectin are discussed.

Tart Cherry, Control of American Plum Borer and Sesiid Borers with a Chemical Insecticide and an Entomopathogenic Nematode, 1996

Abstract Lorsban 4EC and the entomopathogenic nematode Heterorhabditis bacteriophora, formulated as the commercial product Cruiser, were tested for the control of APB and the sesiid borers in two tart cherry orchards. The infestation in both was relatively low. Efficacy of the following treatments was evaluated in each orchard: Lorsban applied by handgun on 24 May (petal fall), of 24 May + 30 Jul (APB 2nd flight peak); Cruiser applied by handgun or injector on 26 Jun (1st generation larvae present) or on 26 Jun + 16 Aug (2nd generation larvae present). The treatments were arranged in a CR design with 5 single-tree replicates per treatment in each orchard. Handgun applications were made at 350 psi. The trunk was sprayed to runoff from ground level to the lowest scaffold limbs. Care was taken to direct the spray stream into openings in the bark. An average of 2 gal of finished spray was applied per tree/application. Injector applications were made using a backpack sprayer, equipped with a single adjustable stream nozzle (Spraying Systems Co., Model 5500 Adjustable Conejet 18x), driven by CO2 at 70 psi, inserted into all openings in the bark from ground level to the lowest scaffold limbs, and sprayed until the point of flooding. An average of 0.3 gal of finished spray was applied per tree/application. Control of APB and sesiid larvae was evaluated, in Oct, by removing bark from the point of all openings in the bark to the edge of live cambium, and counting all live larvae that could be found. Larvae were categorized as APB or sesiid.

Bloom Thinning of `Winblo' Peach and `Fantasia' Nectarine with Monocarbamide Dihydrogensulfate

Mature `Winblo'/Lovell peach [Prunus persica (L.) Batsch] trees in Georgia were treated with five concentrations of D-88, a 79 % to 82 % active ingredient formulation of monocarbamide dihydrogensulfate: 0 (water only), 2.5, 5.0, 7.5, and 10.0 ml·liter-1. All treatments were made by airblast application at 1200 liters·ha-1 when trees were at 95% full bloom. The number of flowers on three limbs per tree was counted 3 days before and fruitlets 25 days following treatment. Regression analysis revealed a linear thinning response to concentration, with 10.0 m1·liter-1 reducing the number of flowers per limb cross-sectional area by 56% over the nonthinned control. Mature `Fantasia' nectarine trees in New Zealand were treated with four concentrations of D-88: 0 (water only), 2.5, 3.75, and 5.0 ml·liter-1. All treatments were made by handgun application to runoff when trees were ≈2 days past full bloom. The number of flowers per limb was counted 6 days before and fruit 62 days following treatment. Regression analysis revealed a linear thinning response to concentration, with 5.0 ml·liter-1 reducing the number of flowers per limb by 55 % over the nonthinned control. Total yield (kilograms of fruit) per tree was the same for all treatments, although fruit size on sprayed trees was larger. No phytotoxicity or fruit finish injury was observed.

CHEMICAL THINNING OF `GRANNY SMITH' APPLE

Under California conditions `Granny Smith' apple does not “self-thin” sufficiently to promote good return bloom nor to provide fruit size desired for the fresh market. Preliminary studies conducted during 1985-87 indicated that 1-naphthyl N-methylcarbamate (carbaryl), 1-naphthaleneacetic Acid (NAA), and 1-naphthaleneacetamide (NAD) could be useful for thinning `Granny Smith'. Detailed studies conducted in 1988 and 89 using dilute handgun applications demonstrated that all 3 materials provided reasonable thinning as shown by fruit set counts. NAA and NAD tended to slow fruit growth as compared to carbaryl. Carbaryl tended to uniformly thin clusters while NAA and NAD were more likely to remove all the fruit from some clusters and few fruit from others, especially in 1988. Compared to the control, all materials applied in 1988 improved return bloom in 1989 with carbaryl having a slightly greater effect than NAA and NAD. As a result of these studies carbaryl at 1.7 to 2.2 kg (active ingredient) per ha as a dilute application is being suggested for grower trials in California.

CHEMICAL THINNING OF `GRANNY SMITH' APPLE

Under California conditions `Granny Smith' apple does not “self-thin” sufficiently to promote good return bloom nor to provide fruit size desired for the fresh market. Preliminary studies conducted during 1985-87 indicated that 1-naphthyl N-methylcarbamate (carbaryl), 1-naphthaleneacetic Acid (NAA), and 1-naphthaleneacetamide (NAD) could be useful for thinning `Granny Smith'. Detailed studies conducted in 1988 and 89 using dilute handgun applications demonstrated that all 3 materials provided reasonable thinning as shown by fruit set counts. NAA and NAD tended to slow fruit growth as compared to carbaryl. Carbaryl tended to uniformly thin clusters while NAA and NAD were more likely to remove all the fruit from some clusters and few fruit from others, especially in 1988. Compared to the control, all materials applied in 1988 improved return bloom in 1989 with carbaryl having a slightly greater effect than NAA and NAD. As a result of these studies carbaryl at 1.7 to 2.2 kg (active ingredient) per ha as a dilute application is being suggested for grower trials in California.

Apple, Savey Evaluation, 1985

Abstract Testing was conducted at Twin Ridge Orchards in Shenandoah Junction, WV under a DuPont Experimental Use Permit. Treatments were applied on 15 Apr (pink) by DuPont to approximately 0.33-ha plots of 11 and 12-year-old trees with a Tifone 3-point hitch airblast sprayer delivering 991 1/ha at a travel speed of 3.22 k/hr. Because of a high mite population, the check was treated with a handgun application of Vydate 2L at 947 ml per 100 gal of water on 27 May. Treatment effectiveness was determined by sampling 25 leaves from the periphery of each of 4 trees, removing mites with a mite-brushing machine and counting active stages with a binocular microscope.

Timing and Effectiveness of Insecticide Treatments Against the San Jose Scale (Homoptera: Diaspididae)

Various types of petroleum oil alone, methidathion or chlorpyrifos alone, and combinations of oil with the two insecticides applied as a single dilute spray at the ½-in. green growth stage were all highly effective against overwintering Quadraspidiotus perniciosus (Comstock). During the summer, handgun applications of dilute methidathion, azinphosmethyl, encapsulated methyl parathion, chlorpyrifos, diazinon, methomyl, and fenvalerate effectively prevented fruit infestation when sprays were applied against crawlers. Two applications during each generation of crawlers, one at the beginning and another 10 to 14 days later, provided the best control. In tests conducted in 1983 in the Hudson Valley when materials were applied with airblast sprayers, fruit infestation was considerably more severe in commercial orchards treated with azinphosmethyl than in those sprayed on the same schedule with encapsulated methyl parathion or chlorpyrifos. A SJS forecast model was developed to allow growers to time summer sprays against both crawler generations. Validation trials conducted in 1983 demonstrated that this forecast model was somewhat more reliable in predicting crawler emergence in New York than the Predictive Extension Timing Estimation Model and was sufficiently accurate to be used in practical management programs.

Potential of Tree Washes as a Management Tactic Against the Pear Psylla12

The effects of tree washes on populations of Psylla pyricola Foerster and fruit quality were examined. Handgun applications of tree washes removed pear psylla honeydew and reduced fruit russet. In addition, tree washes which contamed a wetting agent increased mortality of pear psylla nymphs. Tree washes applied by a speed sprayer were as effecttve as handgun washes in removing pear psylla honeydew. Tree washing holds promise as a tactic to be integrated with biological and chemical control to manage arthropod pests of pear in north central Washington.

Apple, Insect Control, Hudson Valley, 1977

Abstract Apple, Insect Control, Hudson Valley, 1977: Insecticide treatments were evaluated in a seasonal control program conducted in a thirteen-year-old planting on the EM 2 rootstock. Eight-tree plots containing from 5 to 7 different apple cultivars were replicated 3 times in a randomized complete block design. Treatments were applied dilute to runoff using ca 3.8 gal spray/tree (370 gal/acre) with a handgun sprayer at 425 psi. Treatments were applied at pink (Mcintosh) April 19, petal fall May 13, and in 6 cover sprays -- May 25, June-13, June 27, July 14, July 28, and Aug 11. The Ambush, Croneton + Guthion, Dipel, and Penncap treatments were applied June 9, but 2.2 in. of rain fell shortly after application and prior to drying, so they were reapplied with the rest of the treatments on June 13. Additional sprays applied over the entire block for disease control included: Difolatan 4F 5 qt/100 gal, Apr 1 (Handgun application), and Cyprex 65W 8 oz/100 gal on May 3, May 16, June 6, and June 21 (airblast application, 3X, 133 gal/acre). The ‘Rome Beauty’ and ‘Cortland’ cultivars were thinned with 8 ppm NAA, while the ‘Golden Delicious’ were thinned with 16 ppm NAA on May 18. A miticide (Plictran 50W 4 oz/100 gal) was applied along with the following treatments on July 14: Ambush 25W, Dipel W, Penncap 2F, SD 43775 2.4EC 1.3 oz, and Sumithion 40W. Above normal temperatures during April resulted in an early bloom and consequent early harvest. Rainfall was below normal for May and June but above normal for September.

The Commercial Implications of Gibberellin A4A7 Plus Benzyladenine for Improving Shape and Yield of ‘Delicious’ Apples1

Abstract Gibberellin A4A7 (GA4-7) and benzyladenine (BA) were applied to ‘Starkrimson Delicious’ apples from 1969 through 1972. In initial tests, GA4-7 + BA (50 to 200 ppm each) increased fruit length, fruit wt and length/diam ratio (L/D) but did not alter diam or fruit color. Firmness and seed numbers were reduced only at 200 ppm. At concn above 50 ppm flower initiation was substantially reduced. Concentrations of 25 ppm were as effective as 50 ppm but concentrations below 25 ppm were not effective. To be most effective, these materials must be applied between full bloom and petal fall. In general, a single application was more effective than split applications. Repeated annual applications of 50 ppm resulted in continued good response and no adverse effects. In one of the 4 years tested, fruit set but not commercial crop, was significantly reduced by applications of GA4-7 + BA. Air blast applications were as effective as hand gun applications even when the amount of spray mixture/acre was substantially reduced. The average fruit weight response in all experiments reported was 12 and 20% at 25 and 50 ppm, respectively. The improved fruit shape and increased fruit mass could justify the use of GA4-7 + BA in apple producing areas where post bloom temp conditions reduce “typiness”.

Spray Deposits on Apple Trees Following Applications by Three Types of Sprayers1

The R.S.M. Sprayer, a new lightweight air blast sprayer made in Denmark, was compared with the Speed Sprayer and a high pressure hand gun on small, medium, and large apple trees. Coverage was measured by analyzing leaves from bottom, middle, and top portions of the trees for lead following the application of lead arsenate. The most uniform coverage over the trees was obtained by the hand gun application, followed by the Speed Sprayer, while the R.S.M Sprayer gave slightly less uniform coverage. The R.S.M Sprayer produced an even, small droplet deposit on the leaf surfaces.