Tractor-mounted Boom Sprayer Research Articles

Performance evaluation of tractor mounted boom sprayer on chilly crop

Chilli (Capsicum annuum L.) is an important vegetable and spice crop belongs to Solanaceae family which grown all over the world. Dried pods contain 36 gms of carbohydrates, 18 gms of proteins, and excellent source of vitamin A and vitamin C which together provide roughly 160 calories of energy per 100 gms (Narayanan et al., 1999). Area, production and productivity of Chilli in India was 7.43 Lakh ha, 19.14 Lakh Tonnes and 2576 kg/ha, respectively (Anonymous, 2018). Keeping in mind, above parameters the performance of tractor operated boom sprayer was tested on Chilly crop. Under laboratory conditions, the designed boom sprayer performed excellently at 0.90 l/min nozzle discharge and 689.5 kPa operating pressure. It was observed that droplet size, spray uniformity, and droplet density was influenced by the nozzle discharge rate and pressure of 0.45, 0.70, 0.90, and 1.35 l/min and 275.8, 413.7, 551.6, and 689.5 kPa, respectively. The Volume Median Daimater (VMD), Uniformity Coefficient (UC) and Droplet Density (DD) of the existing boom sprayer have 130.9-206.36 µm, 0.98-1.39 and 11-27 number of droplets/cm2, respectively, for nozzle 0.9 lpm and pressure 689.5 kPa. The modified sprayer has droplet sizes between 125.04 and 181.42 m, droplet densities between 16 and 27 number of droplets/cm2, and uniformity coefficients between 0.99 and 1.25 at nozzle discharges of 0.90 l/min. With the 689.5 kPa working pressure and 0.90 l/min nozzle discharge, the designed boom sprayer offers notably higher discharge and nozzle pressure in each individual nozzle than the existing sprayer.

Laboratory Performance Evaluation of Tractor Mounted Boom Sprayer on Brinjal Crop

Brinjal is one of the most popular and principal vegetable crops grown in India. The most common method of applying pesticides to the field crops in the more developed and relatively wealthy agricultural regions of the world is with hydraulic boom sprayers. The working principal of the tractor mounted boom sprayer is to move the spray liquid to the individual nozzle along the boom. Due to inefficient spraying machine lot of pesticide was loss. The proposed sprayer was therefore tested using the pressure gauge and droplet analyzer in the laboratory for brinjal crop. The developed control valve assembly of boom sprayer was tested in a laboratory in terms variables viz., of droplet size, droplet density, uniformity coefficient, nozzle pressure and nozzle discharge for four level of operating pressure (278, 413, 551 and 689 kPa) and number of active openings of on-off valves (all valves open, one valve closed, two valves closed, three valves closed and four valves closed). The deposition of droplet was taken at top, middle and bottom position of plant and on upper and lower leaf surface. The nozzle pressure increases from 501.13 to 1093 kPa while closing the on-off valves of boom sprayer at 689 kPa operating pressure. The nozzle discharge increases from 0.88 to 1.35 l min-1 while closing the on-off valves of boom sprayer at 689 kPa operating pressure.

Identification of Tobacco Crop Based on Machine Learning for a Precision Agricultural Sprayer

Agrochemicals, which are very efficacious in protecting crops, also cause environmental pollution and pose serious threats to farmers’ health upon exposure. In order to cut down the environmental and human health risks associated with agrochemical application, there is a need to develop intelligent application equipment that could detect and recognize crops/weeds, and spray precise doses of agrochemical at the right place and right time. This paper presents a machine-learning based crop/weed detection system for a tractor-mounted boom sprayer that could perform site-specific spraying on tobacco crop in fields. An SVM classifier with a carefully chosen feature combination (texture, shape, and color) for tobacco plant has been proposed and 96% classification accuracy has been achieved. The algorithm has been trained and tested on a real dataset collected in local fields with diverse changes in scale, orientation, background clutter, outdoor lighting conditions, and variation between tobacco and weeds. Performance comparison of the proposed algorithm has been made with a deep learning based classifier (customized for real-time inference). Both algorithms have been deployed on a tractor-mounted boom sprayer in tobacco fields and it has been concluded that the SVM classifier performs well in terms of accuracy (96%) and real-time inference (6 FPS) on an embedded device (Raspberry Pi 4). In comparison, the customized deep learning-based classifier has an accuracy of 100% but performs much slower (0.22 FPS) on the Raspberry Pi 4.

Spray drift reduction under Southern European conditions: A pilot study in the Ecopest Project in Greece

The objective of this work was to generate spray drift data from pesticide application in the field comparing spray drift from traditional equipment with emerging, anti-drift technologies. The applications were carried out in the Kopais area in central Greece. Currently few data exist as regards to pesticide spray drift in Southern European conditions. This work details the data for ground and airborne deposition of spray drift using the methodology developed in the UK by the Food and Environment Research Agency (FERA). Three trials were performed in two days using sunset yellow dye which deposited on dosimeters placed at specific distances from the edge of the sprayer boom. The application was carried out with a tractor mounted boom sprayer, which was of local manufacture, as were the nozzles of Trial I, being flat fan brass nozzles. For Trials II and III anti-drift nozzles were used. The boom sprayers were used with the settings as employed by the farmers for the routine pesticide applications. The results of this work indicate that drift was significantly reduced when anti-drift nozzles were utilized.

Segurança das condições de trabalho de tratorista em aplicações de herbicidas em soja e amendoim e eficiência de equipamentos de proteção individual

Teve-se o objetivo de avaliar a eficiência de um conjunto de equipamentos de proteção individual no controle das exposições proporcionadas ao tratorista aplicando herbicidas nas culturas de soja e de amendoim com o pulverizador de barra e a segurança dessas condições de trabalho. Os pulverizadores utilizados foram os convencionais empregados nas duas culturas para as aplicações de herbicidas em pré-plantio incorporado (ppi), em pré-emergência (pré) e em pós-emergência inicial (pós), com volumes de 200 L ha-1, e 150 L ha-1 apenas na aplicação em pós, na cultura de soja. As exposições sem EPIs foram de 102,77 mL de calda por dia nas aplicações em ppi, 39,62 em pré e 47,14 em pós-emergência. A eficiência dos EPIs no controle das exposições dérmicas foi de 76,5% em ppi, 50,9% em pré e 75,3% em pós-emergência. Na cultura de soja, foram seguras para o tratorista, sem ou com EPIs, as aplicações de pendimethalin, imazaquin e flumetsulam em ppi; de pendimethalin, acetochlor, clomazone, flumioxazin, imazaquin, metribuzin, sulfentrazone, dimethenamid e flumetsulamem em pré, e de bentazone, glyphosate, imazethapyr, quizalofop-ethyl, chlorimuron ethyl e oxasulfuron em pós. Na cultura de amendoim, sem e com EPIs, foi segura a aplicação de pendimethalin em ppi; em pré, a aplicação de alachlor foi classificada como insegura, sem ou com o uso dos EPIs.

EFFECT OF MESSENGER-TREATED TOMATOES ON BEET ARMYWORM

Seedlings were transplanted in a sandy loam type soil on 12 Jun at the University of California's South Coast Research and Extension Center. Experimental plots were four rows wide (5-ft centers) by 40 ft long and separated by a 5-ft buffer. The tomato transplants were drip irrigated (water pH 7.2-7.5). Treatments were replicated four times in an RCB design. A drench of Messenger at 9 oz./acre was applied to the tomatoes 1 wk before transplanting. Once the plants were in the field, the Messenger-sprayed treatments were initiated on an every-other-week basis at 4.5 oz/acre. Application dates were 26 Jun, 12 and 25 Jul, 9 and 23 Aug for a total of five post-transplant applications. A tractor-mounted boom sprayer with six nozzles per row incorporated D-3 orifice disks, #25 cores, and 50-mesh screens. Operating pressure was 100 psi delivering 100 gpa. All treatments received Activator 90 at 0.125% vol/vol as a spreader sticker. Additionally, a dechlorinator was used in the spray tank water.

EVALUATION OF ADMIRE FOR THE CONTROL OF CUCUMBER BEETLES AND BACTERIAL WILT IN PUMPKIN, 2000

This study was undertaken to evaluate Admire for controlling bacterial wilt as well as cucumber beetles, for which it was recently labeled. Evaluation included comparison with the industry standard of weekly foliar applications of Sevin. Cucumber beetles vector Erwinia tracheiphila, the causal agent of bacterial wilt. An experiment was conducted at the Long Island Horticultural Research and Extension Center in Riverhead, NY, in a field of Haven loam soil. Fertilizer (1000 lb/acre of 10-10-10) was broadcast and incorporated on 30 May. To manage Phytophthora fruit and crown rot, Ridomil Gold EC (1 pt/acre) was broadcast over the entire field then incorporated on 31 May. The herbicides Curbit EC (1 pt/treated acre) and Command 4EC (4 pt/treated acre) were applied on 21 Jun in a 10-inch band over the planted rows, then incorporated by irrigating. Average monthly high/low temperatures (F) were 81/61 in Jun, 81/64 in Jul, and 81/65 in Aug. Rainfall (inches) was 4.24, 4.7, and 2.42 for these months, respectively. The field was irrigated (» 1.0 inch) on 6-7 Jul and 13 Jul. Treatments were randomized in four complete blocks. The wilt-susceptible cultivar ‘Merlin’ was selected. Plots were double 12-ft rows each with five plants spaced 30 inches apart in rows spaced 11.3 ft apart. Plots were spaced 13 ft apart in the row. Seeding was done by hand on 20 Jun. A tractor-drawn Cole planter was used to open the furrow and a hand push-hoe was used to close the furrow after seeding. Admire was applied at 1.1 fl oz/1000 linear ft of row after seeding, using a CO2-pressurized backpack sprayer and hand-held boom equipped with a TeeJet TJ-60 4003 EVS twinfan nozzle. Two methods for applying Admire were compared: in the furrow with the seed (20 Jun) and in a 2-inch band over the row after closing the furrow (21 Jun). Herbicides were applied on 21 Jun, followed by irrigation (about 0.25 inches). Admire was also applied in furrow followed by four weekly applications of Sevin XLR during Aug. Applications of Sevin were originally planned to be started when the action threshold of 1 beetle/plant was reached. However this did not occur. Foliar application of Sevin XLR and Avaunt 30WG were made weekly from emergence (1, 8, 15, 21, and 29 Jul; and 4, 11, 18, and 25 Aug). The first six applications were made using a CO2-pressurized backpack sprayer and hand-held boom equipped with TeeJet TJ-60 4003 EVS twinfan nozzles that delivered 60 gpa at 30 psi. The boom was equipped with one nozzle while plants were small. Three nozzles were used beginning on 15 Jul. The remaining applications were made with a tractor-mounted boom sprayer equipped with D3-45 hollow cone nozzles spaced 11 inches delivering 100 gpa at 210 psi. Plants were examined weekly for live and dead cucumber beetles, feeding damage, and symptoms of bacterial wilt. Wilt severity of each plant was assessed weekly from 5 Jul through 5 Sep as percentage of plant wilted. Wilt incidence in each plot was calculated for plants that were at least 50% wilted. Pathogen presence was confirmed by examining thin sections from stems of wilted plants.

EVALUATION OF TWO SYSTEMIC INSECTICIDES FOR CONTROL OF MELON APHID AND SILVERLEAF WHITEFLY ON SQUASH, 1998

EVALUATION OF TWO SYSTEMIC INSECTICIDES FOR CONTROL OF MELON APHID AND SILVERLEAF WHITEFLY ON SQUASH, 1998: Two rates of CGA-293343 and one rate of CGA-293343 in combination with weekly applications of CGA-245704 (a fungicide) were evaluated for efficacy against melon aphid and silverleaf whitefly and compared with a standard, Admire. Yellow crookneck squash, 'Dixie,' was direct-seeded on 16 Apr at the Central Florida Research and Education Center, Leesburg, FL. Soil type was Alachua fine sand. Each plot consisted of four 35-ft rows, 6 ft apart, with plants spaced 2.5 ft apart within the row. Treatments were replicated four times in an RCB design. Admire and CGA-293343 were applied as drenches (1 pt diluted formulation per hill) at planting. CGA-245704 was applied weekly as a foliar spray, beginning on 20 May and ending on 10 Jun, with a 2-row tractormounted boom sprayer with 14 Albuz (lilac) ceramic hollow cone nozzles delivering 110 gpa at 200 psi. Five nozzles were spaced 8 inches apart over each row, and 2 drop nozzles were positioned to spray the sides of each row. Rates are given in the tables. On 12 May, all plants in all plots were infested with melon aphids from a laboratory colony. Adult whiteflies from a laboratory colony were released in the plots at 2to 3-d intervals from 12 to 28 May. Adult whiteflies were counted by turning over the fourth leaf down from the terminal shoot of 20 plants per plot on 19 May and 2 Jun. Aphids and whitefly eggs and nymphs were counted on 20 leaves of similar size per plot on 19 and 26 May and on 2 and 9 Jun. Aphids were counted on whole leaves. Whitefly eggs and nymphs were counted on 3 leaf disks from half of each leaf (total area of 3 disks = 1.0 in2). A square root transformation was used to stabilize the variance of counts for analysis. A two-way ANOVA and a mean separation test (Waller-Duncan k-ratio test) were used to determine significant differences among treatments.

Control of Potato Leafhopper on Potatoes Using Reduced Ratesl of Insecticides, 1997

Abstract Potatoes were planted 19 May at the University of Minnesota Agricultural Experiment Station, Rosemount, MN. Plant spacing was 36 inches between rows and 12 inches between plants within rows. Treatments were arranged in a RCB design with 3 replications. Plots were 8 rows wide by 40 ft long, separated by 12 ft of al-falfa borders on all sides to enhance PLH population. Thirty-five midplant leaves were sampled from the center four rows of each plot. Pre-treatment counts and treatment applications were made 29 Jul. All treatments were applied with a tractor-mounted Brittonya boom sprayer delivering 45 gpa at 90 psi with 3 nozzles per row. Post-treatment counts of PLH nymphs were made 30 Jul, 24 hours after treatment. Early and late blight were controlled by eight applications of chlorothalonil. Analyses of variance were calculated following transformation of the data using logl0(x).

Potato Pest Control, 1997

Abstract ‘Kennebec’ potatoes were planted 23 May at the Fry Farm, OARDC, Wooster, OH. Plant spacing was 38 inches between rows and 9 to 10 inches between plants. Fertilizer was applied at planting (1750 lb/acre 10-20-20). The Admire 2F (in-furrow) treatment was applied at planting using a CO2 compression sprayer at 20 psi with a 8004 flat-fan nozzle delivering the insecticide into the seed furrow. The field was treated for weed control on 10 Jun with 0.67 lb/acre of Sencor DF plus Dual 8 E at 2 pt/acre. Fungicide, 1.5 lb/acre Pencozeb DF, was applied 2, 10, 17, 24 Jul, and 26 Aug. Bravo Ultra at 1.33 lb/acre was applied 4 Sep. Paraquat, 1 qt/acre, was applied 18 Sep as a vine killer. Plots were two rows wide and 40 ft in length, with 9-ft alleys separating plots and 3-ft alleys separating blocks. Treatments were arranged in a RCB design. Foliar treatments were initiated when the first generation larvae were increasing in the plots. Foliar applications of Provado were made 27 Jun and 12 Aug only. All other foliar treatments were applied 27 Jun, 11 Jul, 12 and 28 Aug. A spreader-sticker was added to all M-Trak applications. Cygon 4 E, 1 pt/acre, was added to the M-Trak treatment 11 Jul to suppress PLH populations. Foliar treatments were applied with a tractor-mounted drop-nozzle boom sprayer delivering 50 gpa at 50 psi with three D-4 hollow-cone nozzles/row. Number of egg masses, small (stadium 1-2), large (stadium 3-4) larvae, and adults were counted and percent defoliation was visually estimated in five 1 -m lengths of row per plot. Leafhopper nymphs and aphids were sampled by visually inspecting 25 compound leaves per plot on each sampling date. Hopperburn was rated 16 Jul by inspecting ten leaves per plot and assigning a damage rating for each leaf as follows; 0 = no symptoms, 1 = curling only, 2 = curling with chlorosis or brown edges. We report the cummulative rating for the ten leaves in each plot. For example, if all ten leaves in a plot had curling and brown edges then the cummulative rating would be 20; if all ten leaves had only curling then the cummulative rating would be 10. Potatoes were harvested 2 Oct and graded 23 Oct, separating tubers into “A” and “B” sizes and culls (rotted or damaged).

Insect Control on Staked Tomatoes, 1997

Abstract Six-week-old transplants were set on 4 July at the Mountain Horticultural Crops Re-search Station (Fletcher, NC). Plants were set 18" apart within 20-ft rows and rows were on 10-ft centers. Single-row plots were arranged in a RCBD with four replications. Snap beans and squash were interplanted between treatment rows in an attempt to increase populations of stink bugs (SB) and thrips. Materials were applied on 6, 15 and 25 Aug, and 5 and 15 Sep with a tractor-mounted boom sprayer delivering 50-125 gpa (gpa increased as plants grew) through 7 hollow-cone nozzles per row (three nozzles on each side and one overhead). The list of evaluated materials appears in the results tables. The transplants used in the Confirm 70 W treatment, which was targeted at lepidopterous pests, were treated in the flat with Admire just prior to planting. PA populations were monitored by observing 10 leaves (3rd most recently expanded) per plot and recording the number infested with ≤ 1 apterous aphid. Pink stage fruit were harvested on 22 and 29 Aug, 5, 12, 19, and 26 Sep and 3 and 10 Oct. The total number of fruit and number damaged by TFW, SB, and thrips were recorded. All data were analyzed using a two-way ANOVA and means were separated by LSD (P = 0.05).

Control of Pickleworm on Squash with Selective Insecticides, 1997

Abstract Insecticides specific for lepidopterous pest-were compared with a standard, Thiodan, and an untreated check for control of pickleworm. Squash was direct seeded on 1 Apr at the Central Florida Research and Education Center, Leesburg, FL. Each plot consisted of four 25-ft rows, 6 ft apart with plants spaced 2.5 ft apart. Treatments were replicated four times in an RCB design. All chemicals were applied with a 2-row tractor-mounted boom sprayer with 18 Albuz (lilac) ceramic hollow-cone nozzles spaced 8 inches apart, delivering 133 gpa at 200 psi. Latron CS-7, a surfactant, was tank-mixed with Confirm and RH-2485 at a concentration of 0.12% vol:vol. Treatments were applied weekly from 14 May to 11 Jun. Fruits were harvested, separated into marketable and damaged, counted, and weighed three times per week from 12 May to 16 Jun. An analysis of variance and a mean separation test (WD) were used to determine significant differences among treatments.

Control of Green Peach Aphid on Potato, 1997

Abstract Potatoes were planted 19 May at the University of Minnesota Agricultural Experiment Station, Rosemount, MN. Treatments were replicated sixteen times in a completely randomized design. Plots were 8 rows (36-inch row spacing) wide by 30 ft long with 12-ft alleyways separating plots. On 8 Aug, a pre-treatment count was made and all treatments were applied on 9 Aug. Treatments were applied with a tractor-mounted boom sprayer delivering 45 gpa at 90 psi with three nozzles per row. Plots were treated with Asana or Methoxychlor every 7 days beginning at late June to enhance the aphid population and to control potato leafhopper. Early and late blight were controlled by weekly applications of chlorothalonil or mancozeb. Thirty-five midplant leaves were sampled from the center four rows of each plot on each sample date.

Evaluation of a Selective Insecticide for Control of Melon Aphid on Cantaloupe, 1997

Abstract Two rates of CGA-215944 50 WP, one tested with as well as without the addition of a wetting agent, Kinetic (0.094%, vol:vol), were evaluated for effectiveness and residual activity and compared with a standard, broad-spectrum insecticide, Thiodan 3 EC. Cantaloupe was direct seeded on 2 Apr at the Central Florida Research and Education Center, Leesburg, FL. Each plot consisted of four 35-ft rows, 6 ft apart with plants spaced 2.5 ft apart. Treatments were replicated four times in a RCB design. On 25 Apr, all plants in all plots were infested with melon aphids that had been reared on squash under row covers to prevent predation and parasitism. All chemicals were applied with a 2-row tractor-mounted boom sprayer with 18 Albuz (lilac) ceramic hollow-cone nozzles, spaced 8 inches apart, delivering 133 gpa at 200 psi. Aphids were counted on 20 leaves of similar size per plot each week for 7 wk beginning on 13 May and ending on 24 Jun. Leaves were collected at least 5 DAT. Treatments were applied only when the grand mean of a treatment (the mean of the four replicate means) was equal to or greater than a treatment threshold of 5 aphids per leaf. Thus, all treatments were applied on 7 May, but on 21 May, only the higher rate of CGA-215944 was applied; on 28 May, only the lower rate without Kinetic; on 4 Jun, only the lower rate with Kinetic; and 18 Jun, only the higher rate. A square root transformation was used to stabilize the variance of counts for analysis. A two-way ANOVA and a mean separation test (Waller-Duncan k-ratio test) were used to determine significant differences among treatments.

Impact of Insecticides on Tomato Insects 1996

Abstract Seedlings were transplanted in a sandy loam type soil on 18 June at the University of California’s South Coast Field Station in Santa Ana, California. Experimental plots were 4 rows wide (5-ft centers) by 40 ft long and separated by a 5-ft buffer. The tomato transplants were drip irrigated (water pH 7.2-7.5). Treatments were replicated 4 times in a RCB block design. Weekly applications were initiated at first fruiting. Application dates were 25 Jul, 1, 8, 15, 22, 29 Aug, and 5, 12, 19 Sep. A tractor-mounted boom sprayer with 6 nozzles per row incorporated D-3 orifice disks, #25 cores, and 50 mesh screens. Operating pressure was 100 psi delivering 100 gpa. Spreader sticker (Leaf Act 80) was included for all treatments at 0.04%, except Fortune AZA and Neemix (+0.5% crop oil) and Aphistar (+ silwet @ 2 oz./lOO gal.). Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four 9 by 11 inch trays/replicate from 30 Jul through 18 Sep, inclusive. On 23-25 Sep, 200 mature-green to ripe fruit were harvested from the center 2 rows of each replicate (800 per treatment) and examined for internal damage (primarily by H. zed) and external damage (primarily by S. exigua and K. lycopersicella). Leafminer populations were moderate. Some treatments increased leafminer density as compared to the control.

Control of Colorado Potato Beetle, 1996A

Abstract Potatoes were planted 21 May at the University of Minnesota Agricultural Experiment Station, Rosemount, MN. Plots were 4 rows wide by 50 ft long with 12 ft alleyways separating plots. Plant spacing was 36 inches between rows and 12 inches between plants. Four treatments and an untreated check plot were replicated 4 times in a RCB design. Early and late blight were controlled by seven applications of chlorothalonil. Foliar insecticide applications were made 10 Jul and 16 Jul. Treatments were applied with a tractor-mounted Brittonya boom sprayer delivering 40 gpa at 90 psi with 3 nozzles per row. Number of small (instar 1-2) and large (instar 3-1) larvae were counted on 5 randomly selected plants per row in each plot (20 plots per plot) on 11 Jul and 17 Jul. Percent defoliation estimates were made from whole plant inspection of 5 randomly selected plants per row in each plot (20 plants per plot) on 17 Jul. Analyses of variance were calculated following transformation of count and percentage data using log,0(x + 1) and arcsim/(x), respectively. Due to the very high CPB pressure in this location, some plots were completely defo-liated by the third week in July. No treatments were applied after 17 Jul due to near absence of a second generation of CPB.

Control of Green Peach Aphid on Potato, 1996

Abstract Potatoes were planted 21 May at the University of Minnesota Agricultural Experimental Station, Rosemount, MN. Treatments were replicated four times in a RCB design in plots 4 rows wide by 50 ft long. Plant spacing was 36 inches between rows and 12 inches between plants within rows. Plots were separated by 12 ft of cultivated soil. Treatments were applied with a tractor-mounted Brittonya boom sprayer delivering 40 gal/acre at 90 psi with 3 nozzles per row. All plots were treated with Novodor (1 qt/acre) on 7 Jul (30% egg hatch) to control Colorado potato beetle larvae. Additionally, all plots were treated with Asana XL 0.66EC (9.6 oz/acre) on 19 Jul and 26 Jul to enhance the aphid population and to control Colorado potato beetle adults and late instar larvae. Admire 2F was applied over the top of the potato seed pieces just before the furrows were covered. Temik was applied to the soil surface on 30 May. Foliar applications were made 30 Jul and 14 Aug. Treatments that included Asana XL 0.66EC received additional applications of Asana on 2, 9, and 19 Aug. Early and late blight were controlled by eight applications of chlorothalonil. Thirty-five midplant leaves were sampled from the center two rows of each plot on each sample date. Plots were vine-killed 30 Aug. One outer row was harvested from each plot on 17 Sept. Analyses of variance were calculated following transformations of count data using log10(x).

Pesticide Application by Using Riding Type Tractor Mounted Boom Sprayer

Pesticide Application by Using Riding Type Tractor Mounted Boom Sprayer

Pesticide Application by Using Riding Type Tractor Mounted Boom Sprayer

Pesticide Application by Using Riding Type Tractor Mounted Boom Sprayer

Control of Aphids and Whiteflies on Watermelon, 1995

Abstract Watermelon was direct-seeded on 30 Mar at the Central Florida Research and Education Center, Leesburg, FL. Each plot consisted of four 35-ft rows, 7 ft apart with plants spaced 2.5 ft apart. Treatments were replicated four times in an RCB design. Fungicide (mancozeb or chlorothalonil) was applied weekly, usually 2 d after insecticides. All materials were applied with a 2-row tractor-mounted boom sprayer with 18 Albuz (lilac) ceramic hollow cone nozzles, spaced 8 inches apart, delivering 178 gpa at 400 psi or 133 gpa at 200 psi (CGA-215944 and Thiodan only). Silwet (0.02% or 0.03%, vohvol) was tank-mixed with Mycotrol. CGA-215944 was tested for aphid control only and was applied when the number of aphids exceeded five per leaf (high rate on 24 May only, low rate on 24 May and 7 Jun). All other treatments were applied on 24 May, 1,7, 13, and 20 Jun except Thiodan which was not applied on 24 May. Small whitefly nymphs (first and second instars) and large nymphs (third and fourth instars, pupae) were counted and summed on three 0.6-inch diam leaf disks cut from each of 20 leaves per plot for 5 weeks, beginning on 29 May and ending on 26 Jun. Aphids were counted on whole leaves. A square root transformation was used to stabilize the variance of counts for analysis. A two-way ANOVA and a mean separation test (Waller-Duncan k-ratio) were used to determine differences among treatments.