Handgun Sprayer Research Articles

Effects of 22S, 23S-Homobrassinolide and Gibberellic Acid on Occurrence of Physiological Disorders and Fruit Quality of ‘Summit’ and ‘Regina’ Sweet Cherries

Plant growth regulators play a vital role in fruit growth and development. However, effects of compounds belonging to the group of brassinosteroids have not been fully investigated in sweet cherries. One relatively new and one commonly applied growth regulator, 22S, 23S-Homobrassinolide and GA3, respectively, were tested on ‘Summit’ and ‘Regina’ sweet cherries to determine the effects on fruit quality and physiological disorders. The substances were applied with a handgun sprayer at full bloom and at the beginning of fruit development (shuck split) for a 2-year period. GA3 was applied at the concentrations of 25, 50, 100 mgL−1 and 22S, 23S-Homobrassinolide at 0.05, 0.1, 0.5 mgL−1. A combined application of 100 mgL−1 GA3 + 0.1 mgL−1 22S, 23S-Homobrassinolide was also applied. Effects of GA3 and 22S, 23S-Homobrassinolide on fruit weight and size were evident for the concentrations applied and between the seasons for both of the cultivars. Combination of the both growth regulators and 100 mgL−1 GA3 alone produced longer fruits compared to the control trees in ‘Regina’. The 22S, 23S-Homobrassinolide applications increased the firmness of the flesh slightly, but not to a great degree, compared to the GA3 applications alone. The brightness of the red color was better with GA3 applications in ‘Summit’ and ‘Regina’. Brassinosteroid caused the fruits to have comparably dull red color. Total soluble solid contents of the cultivars were influenced by the substances and the year of the application. Stem resistance to separation from the fruit was under the influence of both treatments and seasons. In general, 22S, 23S-Homobrassinolide provided better stem resistance than the GA3 applications. There were no effects of the substances on the development of physiological disorders.

ASSESSMENT OF DERMAL PESTICIDE EXPOSURE INSIDE GREENHOUSES USING FLUORESCENT TRACER METHOD

The main object of the search work is to assess the dermal pesticide exposure inside greenhouses during its application and to compare pesticide pollution resulted from handgun sprayer with its values of a vertical boom sprayer prototype. Fluorescent tracer, is semi-quantitative dermal exposure assessment method based on visual observations of fluorescence images, had been used to demonstrate the extent to which dermal exposure can occur under inadequate protective conditions. 22 body segments (˃ 90% of the total body surface area) scored for all workers. Prototype is superior to handgun sprayer, contaminated area ratio of glasses was 0.28% - no pollution for the mask versus 8.11% and 9.15% respectively. Trunk, buttock, chest and shoulder contaminated area with handgun sprayer were 1.75, 1.60, 0.60 and 6.69 % (front view) and were 1.79, 9.51, 0.73 and 0.00 at back view versus no pollution (0.00 %) in all previous cases with vertical boom sprayer prototype. No pollution in any area of worker’s arms compared to polluted area ranged between 0.00 and 8.17% for handgun sprayer. Contaminated area of gloves (​​5% of total body area) ranged between 0.00 and 0.92 % for vertical spray boom prototype versus 11.72 % - 19.50 % for handgun sprayer. Worker’s legs exposed to some pollution (0.42 % and 0.82%) against more detected exposure extended to 13.36 % for handgun sprayer. Regrettably, workers did not wear safety boots, though no data for feet area, which form about 7 % of total body area, was taken. Tested prototype maintained more working safety conditions when compared to handgun sprayer.

Mancozeb and Kaolin Applications Can Reduce Russet of `Comice' Pear

Mancozeb (Manzate 200) and kaolin (Surround WP) were applied individually and in combination in a commercial pear (Pyrus communis) orchard by air-blast sprayer in two growing seasons and in a research orchard by handgun sprayer in four growing seasons. Mancozeb was applied at 50% bloom, petal fall (PF), PF + 2 weeks and PF + 4 weeks, while kaolin and mancozeb + kaolin were applied at PF, PF + 2 weeks and PF + 4 weeks. Both materials reduced russet in both years of the commercial orchard trial and in 2 years of the research orchard trial. In one trial, kaolin treatment reduced russet to a greater extent than did mancozeb, and in one trial the combination of mancozeb plus kaolin reduced russet to a greater extent than either material alone. The year with the greatest amount of russet was the year with the most rainfall, and the year with the least russet was the year with the least rainfall. Considering that mancozeb may be used in pear orchards for suppression of pear scab (Venturia pirina) and pear psylla (Cacopsylla pyricola), and kaolin may be used for suppression of pear psylla, russet reduction by each of these materials adds to their multipurpose utility.

Effects of Timing of Copper Sprays, Defoliation, Rainfall, and Inoculum Concentration on Incidence of Olive Knot Disease.

The olive knot pathogen, Pseudomonas savastanoi, causes galls on shoots, branches, fruit, and leaves. Shoots girdled by galls die. Any fresh wound is susceptible to infection, but the most common entry sites are leaf scars. Leaf scars are most susceptible to infection during the first 2 days after leaf fall and remain susceptible for 7 more days. Simulated leaf scars on 'Manzanillo' olive trees were created by removing leaves from healthy shoots at approximately monthly intervals from December through June 1997-98, 1998-99, and 1999-2000. Trees were treated with a water suspension of cupric hydroxide (Kocide DF40) at 3 g/liter one, two, or three times in 1998-99 and 1999-2000 with a hand-gun sprayer. Generally, disease control improved with more applications (P = 0.008 and 0.032 in 1999 and 2000, respectively). Disease incidence was greatest on shoots that were defoliated in March 1998, April and June 1999, and March and May 2000. Cumulative rainfall 2 and 9 days after each defoliation was recorded. Disease incidence was positively correlated (P = 0.031 and 0.023 for 2 and 9 days, respectively) with spring (March through June) but not winter (December through February) rainfall. Comparable simulated leaf scars were inoculated in December and April 1997-98 and 1998-99 with 104, 106, and 108 CFU/ml of the pathogen and treated with a water suspension of cupric hydroxide at 3 g/liter using a handheld pump sprayer. Inoculated and noninoculated, nontreated shoots were included. More disease developed in April than in December inoculations (P = <0.0001) in both years. Disease incidence increased with increasing inoculum concentration (P = <0.0001) in both years and was lower in shoots treated with Kocide DF40 (P = <0.0001). Our work demonstrated that the common grower practice of one post-harvest application of copper bactericide provides only minimal protection against olive knot, and that additional sprays in spring are needed to substantially improve disease control.

EARLY SEASON CONTROL OF SAN JOSE SCALE AND CATFACING INSECTS ON PEACH, 2003

The trial was conducted at the Missouri State Fruit Experiment Station in Mountain Grove, MO. The trial block consisted of 13-yr-old, 9-ft-tall 'Red Haven' and 'Encore' trees with 20 20 ft spacing in a 2.2-acre section of a 3.8-acre block. Treatments and an unsprayed check were arranged in a CRB design consisting of two to four replicates. There was a minimum of a one tree buffer between treatments to minimize the effects of insecticide drift. Insecticides were applied to single trees dilute to run-off with a high-pressure handgun sprayer (200 psi) on 30 Apr, 20 May, or both dates. Insecticides were applied on 23 Apr to most of the treatment trees, but because of rain (> 2 inch) shortly after the applications were made, treatments were reapplied on 30 Apr. The first application (30 Apr) corresponded with shuck split and early emergence of first generation adult SJS (33 DD51 after first adult trap catch = 17 Apr). The second application (20 May) corresponded with early emergence of first generation SJS crawlers (17 Apr +402 DD51). Insecticide treatments included Phaser 50 WP, Esteem 35 WP, Pounce 3.2 EC (2 fl oz/100 gal), Provado 1.6F, Assail 70 WP, Diazinon 50W, and Sunspray UltraFine Spray Oil. Danitol 2.4 EC was substituted for the second application (20 May) of Sunspray UltraFine Spray Oil because insufficient quantities of spray oil were available for both applications. A total of 60 peaches per treatment were evaluated for insect damage on 17– 20 Jun (17 Apr +736–815 DD51), at the end of the SJS first generation. In addition to determining presence or absence of SJS damage on peaches, a 0 to 11 quantitative scoring system where 0 = 0, 1 = 0–3, 2 = 3–6, 3 = 6–12, 4 = 12–25, 5 = 25–50, 6 = 50–75, 7=75–87, 8=87–94, 9=94–97, 10=97–100 and 11 = 100 'b surface area infected/damaged was used to estimate the percentage of the fruit surface area damaged by SJS. Peach damage means were separated using a Fisher's Protected LSD Test (P £ 0.05).

Rate and Time of Boron Application Increase Almond Productivity and Tissue Boron Concentration

Previous studies with tree species have demonstrated that foliar boron (B) promotes flowering, fruit set, and yield. However, for most species the optimum time for foliar B application has not been determined. This investigation was undertaken to study the effects of time and rate of B application on almond [Prunus dulcis (Mill D.A. Webb)] tissue B concentration, fruit set, and yield. Solubor (Na2B8O13.4H2O), a commercial product containing 20.5% B, was applied with a handgun sprayer either in September (3 weeks postharvest), December (dormancy), or February (budbreak) at rates of 0, 0.8, and 1.7 kg·ha-1 B to almond cv. Butte at one site (Parlier, Fresno County, Calif.), and of 0, 0.8, 1.25, 1.7, and 2.1 kg·ha-1 B on the same cultivar in August, September, or February at a second site (Orland, Glenn County, Calif.) using Borosol, a polyboronated commercial product containing 10% B. At site 1, September application was more effective in increasing tissue B concentration, fruit set, and yield than were December or February applications. The optimal rate was 0.8 to 1.7 kg·ha-1 B when applied in September. At site 2, application in 1996 and 1997 increased tissue B concentration almost linearly, especially when applied in August and February. Application at the highest rate (2.1 kg·ha-1 B) in September produced the greatest final fruit set and yield in 1996. February applications increased initial fruit set at both sites but were less effective than September applications in increasing yield. Application of B did not affect any yield variable in 1997. These results suggest that B should be applied immediately postharvest (September) for optimal effect on tissue B concentration, fruit set, and yield in almond.

Insect Control on Apples Using Bt, 1997

Abstract A block of ‘Law Rome’ apple trees with a tree-row volume of approximately 200 gpa was used for this study in Dana, NC. Plots consisted of five trees with two trees serving as sample trees set up in a RCBD with four replications. All plots received the same fungicide program throughout the season and received 2% oil at green tip, Asana XL at tight cluster (29 March), and Guthion 50 W at petal fall (8 May). Applications for first-generation TABM were made on 17 Jun and 3 and 16 Jul which corresponded to 3rd, 4th and 5th cover sprays. Applications were made with a handgun sprayer operating at 175 psi and delivering 200 gpa.

Citrus Leafminer Control on Texas Citrus, 1997

Abstract Two rates of Confirm 2°F tank mixed with NR 435 Oil, and Micromite 25 W alone and + NR 435 Oil, were compared with the standard Agri-Mek EC + NR 435 Oil treatment for efficacy against CLM. Treatments were randomized and replicated 4 times on single-tree plots in a block of 4-yr-old orange trees planted on a spacing of 14 X 24 ft. Treatment sprays were applied on 13 Jun and carefully timed to the appearance of CLM eggs and emerging 1st stage larvae on new flush leaves. A HyPro 5200 handgun sprayer with pressure set at 150 psi was used and sprays applied to foliar run-off. At each pre- and post-spray count date, 4 new flush terminals (each with 6-8 leaves) were randomly collected per replicate and taken to the laboratory. All live and dead CLM 1 st-4th stage larvae and pupae were counted on each terminal. CLM were recorded as dead by lack of movement and/or evidence of dessication when examined microscopically at 20X. Percent mortality of all CLM immature stages was determined for each treatment.

Evaluation of Insecticides Against Fruit-Feeding Insects on Apple, 1997

Abstract Treatments were applied to four-tree (including ‘Cortland’) plots replicated three times in a RCB design. All treatments were applied dilute to runoff using a high-pressure handgun sprayer at 300 psi delivering from 190 (prebloom) to 300 (postbloom) gpa depending upon foliage density. Trees on the M.2 rootstock were 34 years old, 10 ft high, and 12 ft wide. Dates of application were: 9 Apr [delayed dormant (DD)]; 22 Apr [pink (P)]; 27 May [petal fall (PF)]; 6 Jun [first cover (IC)]; 19 Jun [second cover (2C)]; 11 Jul [third cover (3C)]; 28 Jul [fourth cover (4C)]; and 8 Aug [fifth cover (5C)]. Fungicides applied to all treatments were Benlate, captan, Dithane, Nova, and Rubigan. Control of fruit-feeding insects was assessed at harvest maturity (18 Sep) by randomly selecting 100 fruit and scoring for external damage by each pest; subsequently, fruits were dissected to detect internal damage. Damage by early PC designates ovipositional scars, while late PC indicates feeding punctures.

Evaluation of Insecticides Against Foliar-Feeding Insect Pests on Apple, 1997

Abstract Treatments were applied to fourtree (of which ‘Delicious’ was included) plots replicated three times in a randomized complete block design. All treatments were applied dilute to runoff using a high-pressure handgun sprayer at 300 psi delivering from 160 (prebloom) to 300 (postbloom) gpa depending upon foliage density. Trees on the M.2 rootstock were 34 year-old, 10 ft high, and 12 ft wide. Dates of application were: 9 Apr [delayed dormant (DD)]; 22 Apr [pink (P)]; 27 May [petal fall (PF)]; 6 Jun [first cover (IC)]; 19 Jun [second cover (2C); 11 Jul [third cover (3C)]; 28 Jul [fourth cover (4C)]; and 8 Aug [fifth cover (5C)]. Fungicides applied to all treatments were Benlate, captan, Dithane, Nova, and Rubigan. Damage by PLH was assessed on 10 Jul by walking the tree perimeter and counting the number of terminals displaying ‘hopperburn’ symptoms per 2-min periods. Damage by second-generation RLH nymphs was assessed on 17 Jul by counting the number of nymphs per 100 randomly selected leaves. Subsequently, cumulative foliar damage by RLH and WALH was estimated on 16 Sep by selecting 25 proximal terminal leaves and rating on 0-4 scale: 0 = no stippling; 1 = slight stippling (&amp;lt;10%); 2 = low stippling (&amp;gt;10-25%); 3 = moderate stippling (26-50%); and 4 = high stippling (51-75%). Damage by second generation STLM was assessed on 6 Aug by counting the number of mines per 100 randomly selected leaves. Damage by JB was assessed on 18 Sep by walking the tree perimeter and counting the number of infested terminals per 2 min.

Apple, Handgun Trials of New Insecticides Against Oblr, 1996

Abstract Treatments were applied with a truck-mounted, high pressure (450 psi), handgun sprayer dilute to run off to single apple tree plots in 2 orchards: ‘Idared’ trees (Brown orchard), which were about 15 years old, 13 ft high, and planted 19 X 27 ft apart, and ‘Rome’ trees (Nesbitt orchard), which were about 8 ft high and planted 11 X 18 ft apart. Treatments were arranged in a RCB design, separated by unsprayed buffer trees, and replicated twice in each orchard. All materials were applied on a 3-spray schedule, at 1st hatch (2 Jul), mid-hatch (16 Jul), and on 29 Jul. Check plots were not sprayed with insecticides during the test. Summer populations of larvae were compared by examining 20-50 growing terminals on each tree for live larvae on 9-11 Jul and again on 23-24 Jul. Fruit damage from the 1st summer generation of larvae was estimated initially on 1-2 Jul and again on 20-24 Aug by sampling up to 100 apples from each tree. At harvest (4 Oct for the ‘Rome’ applies in the Nesbit Orchard and 14-15 Oct for the ‘Idared’ applies in the Brown Orchard), up to 100 applies were sampled from each tree and OBLR damaged fruit was classified according to USDA grading standards into the categories of “Fancy”, #1, and culls.

Peach, Control of Peachtree Borers with Chemical Insecticides, 1996

Abstract Treatments were applied during the late summer of 1995 to mature (greater than 15 year old) Autumhglo peach trees in a commercial orchard. Most trees had heavy gumming at the base, showing symptoms of prolonged borer activity. Treatments were arranged in a RCB design with 4 replicates, 10 trees per replicate for a total of 40 trees per treatment. Applications were made with a Durand Wayland 100 gal. handgun sprayer set at 250 psi. Applications were made on 11 Aug and 26 Sep, and applied to the base of each tree with 1.25 gal of spray volume per tree. Pupal cases were counted on each tree on 6 Sep and 26 Oct, 1995, and again on 7 Aug, 12 Sep and 1 Oct, 1996. Pupal case counts were combined to give yearly totals.

Effect of Acaricides on Predatory Mites, 1996

Abstract This experiment was conducted in a mature ‘Fuji’ orchard in Pateros, WA, with undertree spinner-type sprinklers. A pre-treatment count was used to randomize the treatments among trees with similar mite populations. Three single-tree replicates per treatment were used. The treated trees had buffer trees separating them in the rows, and buffer rows separated rows containing treated trees. Treatments were applied with a handgun sprayer to the point of drip on 28 Aug, 1996. Mites were sampled by collecting 20 leaves/replicate, and were kept cool until counting. Mites were removed from the leaves with a leaf-brushing machine, and counted on the sticky surface of the glass plate with the aid of a stereoscopic microscope.

Citrus Leafminer Control on Citrus, 1996

Abstract Micromite, Alert and Provado were compared with the standard treatment Agri-Mek + NR 435 Oil for efficacy against CLM. Treatments were randomized and replicated 4 times on single tree plots in a 3-yr-old grapefruit orchard on 18 X 24 ft spacing. Trees were sprayed to foliar runoff on 12 Sep using a Hypro 5200 high pressure handgun sprayer operating at 200 psi. At each count date, 4 new flush terminals (each with 10-12 leaves) were randomly collected per replicate and taken to the laboratory. All live and dead CLM lst--4th stage larvae and pupae were counted on each terminal. The insects were recorded as dead by lack of movement and/or evidence of dessication when examined microscopically at 20 X. Percent mortality of all CLM immature stages was determined for each treatment.

Effect of Registered and Experimental Insecticides on Second Generation White Apple Leafhopper, 1996

Abstract The test was conducted in a mature apple orchard (several strains of ‘Delicious’) on the grounds of the Tree Fruit Research and Extension Center. Treatments were replicated 4 times, with each replicate consisting of a single tree. The experimental design was a randomized complete block, using pre-treatment leafhopper populations as the blocking factor. The experimental treatments were applied on 21 Aug, which coincided with the 1st appearance of adults of the 2nd generation. Pesticides were applied with a handgun sprayer to the point of drip. WALH populations were sampled c-a. weekly by counting in situ all live nymphs on 20 leaves per tree, distributed throughout the tree canopy.

Evaluation of Cm-006 for Citrus Red Mite Control, 1996

Abstract Experimental CM-006, alone and tank-mixed with NR 435 Oil or Kinetic adjuvant, were compared with Agri-Mek + NR 435 Oil for efficacy against RdM on nursery citrus. Treatments were randomized and each replicated on 4 potted grapefruit trees (each ca. 2 ft high). Sprays were applied to foliar run-off using a TQ-40 Koke Kap CO2 handgun sprayer nozzled with a 8002 Tee-Jet tip and pressure set at 30 psi. At each count date 3 leaves per replicate tree (12/treatment) were randomly sampled and processed in the laboratory through a Leedom Mite Brushing Machine. RdM from each replicate were collected on a detergent-coated glass disc and counted under a binocular microscope at 20X.

Effect of Experimental and Registered Miticides on Twospotted Spider Mite and European Red Mite, 1996

Abstract This experiment was conducted in a commercial orchard of mature ‘Delicious’ apples at Arrowhead Ranch, Bridgeport, WA. The plot was laid out in 2 rows, with buffer trees between treated trees in the row, and a buffer row between rows containing treatments. A pre-treatment count was made and replicates were assigned to blocks according to initial population and treatments were randomly assigned within replicates. The experimental design was a randomized complete block with 4 replicates. Treatments were applied 5 Jul 1996 with a handgun sprayer operated at about 300 psi. Twenty randomly selected leaves were collected from each replicate tree, and mites were removed from the leaves with a leaf-brushing machine. Mites were counted with the aid of a binocular microscope. A pretreatment sample and weekly post-treatment samples were taken.

Bioassay, Effect of Field-Aged Residues of Azadirachtin and Bacillus Thuringiensis on Neonate Leaf-Roller Larvae, 1995

Abstract Using a leaf-disk bioassay, azadirachtin (Neemix 4.5 F, W. R. Grace &amp; Co.: Conn. &amp; Co.: Conn.) was evaluated alone and in combination with Bacillus thuringiensis (Bt) (Dipel 2X, Abbott Laboratories) for residual effects on PLR and OBLR neonate larvae. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type Delicious on dwarfing roots The treatments were applied on 10 Aug at rates listed in the table with a handgun sprayer at 300 psi to the point of drip, simulating a dilute spray ot approximately 400 gal/acre. Each treatment was replicated three times with one tree in each. Ten leaves were collected from the interior canopy of each tree at 1, 4, 7 and 14 DAT. Two punches (2.3 cm diameter) were taken from each leaf. Four punches were placed in a Petri dish (Falcon 1006, 50X9 mm), keeping the leaves from each replication separate. Petri dishes were chosen randomly, and five 1- to 2-d-old leafroller larvae were placed on the leaves. Five Petri dishes were prepared for each tree and each leafroller species (75 larvae per treatment). The Petri dishes were placed inside a food storage container and kept at 75°F (±2°F) constant temperature and 16:8 photoperiod. Petri dishes were examined after 7 and 14 d and larval survival recorded. Leaves were collected from the treated trees after 7 d and added to the Petri dishes for a fresh food source. All surviving larvae at 14 d were transferred to 3-¼ oz portion cups (Prairie Packaging, S-300) containing artificial leafroller diet. The number surviving to adult, as well as the number that died as larva or pupa and whether or not the leafroller was deformed, was recorded.

Apple, Codling Moth Control with Neemix, Dipel 2X, Imidan and Guthion, 1995

Abstract Neemix, alone and in combination with Dipel 2X, Imidan and Guthion were evaluated for their ability to control CM over the entire season. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type Delicious on dwarfing roots. Treatments were applied to 1-tree plots replicated 5 times in a RCB design. All treatments were applied with a handgun sprayer at 300 psi to the point of drip. The CM injury evaluations were made following the first generation on 19 Jun and at harvest on 31 Aug. Twenty-five apples per replicate were sampled on 19 Jun and the number of fruit injured by CM recorded. At harvest, all the fruits per replicate were sampled and the number of CM and PLR injured fruit recorded. Due to the high percentage of CM-injured fruit at harvest, a 10-fruit subsample was chosen at random from each replicate and the number of CM stings and entries per fruit recorded.

Apple, Obliquebanded Leafroller Control with Spinosad in Summer, 1995

Abstract Spinosad DE-105 1.6% was evaluated for its ability to control OBLR larvae of the summer generation. The test was conducted in an apple orchard at Mattawa, WA. The trees were 3-yr-old Delicious on dwarfing roots. Treatments were applied to 8-tree plots replicated 5 times in a randomized complete block. All treatments were applied with a handgun sprayer at 300 psi to the point of drip, simulating a dilute spray of approximately 400 gpa. The 50% egg hatch and 50% + 14 d treatments were applied 28 Jun and 10 Jul, and the 100% egg hatch and 100% + 14 d treatments were applied 10 Jul and 24 Jul. The post-treatment evaluation was made on 28 Jul. The total number of live OBLR larvae found in a 10-min search on all 8 trees of a treatment replication was counted.