Single-row Plots Research Articles

Lepidopterous Larvae Control on Collards, 1990

Abstract Collards were transplanted Mar, 1990, near Greenville, NC, using a row spacing of 42 inches. Single row plots 20 ft long were replicated 4 times in a randomized complete block design. Alleys of 5 ft were used between replicates. Treatments were applied with a CO2 pressurized backpack sprayer using a single hollow cone nozzle (18 x). Application rate was 80 gal/acre delivered at 60 psi, and Triton B-1956 spreader-sticker was used with all treatments. Applications were made 14, 20, and 27 Nov. Visual estimates of foliar damage to all plants and/ or insect counts on 3 plants per plot were made 20, 27 Nov (before spraying), and on 5 Dec.

Control of Diamondback Moth on Canola, 1991

Abstract Canola was seeded on 20 Aug in single-row plots 16 ft long at the University of Illinois Vegetable Crops Farm, Champaign. Plots were replicated 4 times in a randomized complete block design. Natural populations of DBM were augmented with mid-sized larvae from a laboratory colony. Triton CS-7 adjuvant (6 oz/acre) was included in all sprays except Lannate 1.8 EC and Condor OF. Spray solutions were applied with a 3 gal backpack-type hand sprayer calibrated to deliver 280 gal/acre on 10 Oct. One destructive sample of 5 plants/plot (previously infested with laboratory-reared DBM) was made on 14 Oct. Treated foliage from these plots was used in a laboratory bioassay (see Paper 1 L).

Reflective mulch decreases the spread of two non‐persistently aphid transmitted viruses to narrow‐leafed lupin (Lupinus angustifolius)

SummaryTrials were done in 1987–1989, to investigate the effect of a reflective aluminium painted polythene mulch in protecting rows of narrow‐leafed lupin (Lupinus angustifolius) from infection with two non‐persistently aphid‐transmitted viruses, bean yellow mosaic (BYMV) and cucumber mosaic (CMV). The mulch greatly decreased the rate and extent of spread of BYMV from external sources into mulch‐protected rows in two trials, but was somewhat less effective in a third. The rate and extent of spread of CMV from an adjacent external source into reflective mulch‐protected rows was also greatly decreased in one trial in which the mulch also decreased spread within rows and was effective even when the primary infection source was only 2.5 m away. In a trial sown with CMV‐infected seed (c. 2% seed transmission), the mulch decreased CMV spread from primary foci within rows. Reflective mulch can be used to protect breeders' single row plots of lupins from infection with CMV and BYMV.

Colorado Potato Beetle Control with Biological and Synthetic Insecticides, Pasquotank County, 1989

Abstract Su perior' potatoes were planted near Weeksville, N.C. Single row plots, 6 . 1 B long with rows 1.06 m apart were replicated 4 times in a randomized complete block design. Treatments were applied using a COa pressurized sprayer with a single hollow cone nozzle (18 X) operating at 60 psi to apply 119.2 liter/ha. Treatments were applied 16 May (all) and 24 May (M-One, Trident and Trident II). Visual estimates of foliar damage and/or insect counts were made 23 May and 1 Jun. Larvae were counted on 3 hills/plot. Small larvae were assumed to be 1st and 2nd instars, and large 3rd and 4th.

Lepidopterous Larvae Control on Collards, 1989

Abstract Collards were transplanted near Greenville, N.C., using a row spacing of 1.07 m. Single row plots, 6.1 m long were replicated 4 times in a randomized complete block design. Alleys of 1.5 m were used between replicates. Treatments were applied with a CO2-pressurized backpack sprayer using a single hollow cone nozzle (18 x). Application rate was 122.5 liter/ha delivered at 60 psi, and Triton B-1956 spreader-sticker was used with all treatments. Applications were made 24 and 30 Aug, 7, 13, and 21 Sep. Visual estimates of foliar damage and insect counts on 5 plants were made 30 Aug, 7, 13, 21 and 28 Sep.

Colorado Potato Beetle Control, Currituck Country, 1989

Abstract 'Pungo' potatoes were planted 31 Mar, near Powells Point, N.C. with Thimet 15 G applied in the furrow at the rate of 19.0 kg (form.)/ha. Single row plots, 6.1 m long with 1.06 m between rows, were replicated 4 times in a randomized complete block design. Treatments were applied using a CO2 pressurized sprayer with a single hollow cone nozzle (18 x) operating at 60 psi to apply 132.5 liter/ha. Treatments were applied 9 May (M-One, Trident, and Trident II), and 16 May (all treatments). Plant stand counts were made and the number of infested hills was recorded on 9, 16, and 23 May. Visual estimates of foliar damage and/or insect counts were made 9, 16, 23 May, and 1 Jun. Adults were counted by walking the length of the plot and counting all visible adults. Larvae were counted on 3 hills/plot. Small larvae were assumed to be 1st and 2nd instars, and large 3rd and 4th.

Insect Control on Staked Tomatoes, 1990

Abstract Transplants were set on 15 Jun, at the Mountain Horticultural Crops Research Station, Fletcher, N.C. Plants were set 2 ft apart within rows, and rows were on 10-ft centers. Single-row plots (10 plants) were separated by 10 ft of cultivated soil, and treatments were arranged in a randomized complete block design with four replications. Insecticide applications were initiated at first fruiting, and applied on 18 and 25 Jul, 3, 10, 17 and 27 Aug, 4 and 15 Sep. All applications were made with a CO2 backpack sprayer operating at 100 psi and delivering 100 gal/acre through 3 hollow cone nozzles spaced 12 inches apart on the spray wand. Sprays were applied to both sides of rows so that each row was effectively treated with 6 nozzles/row. PA populations were monitored by observing 10 terminals/treatment (40 total) and recording percentage infested with >1 apterous aphid. Thrips populations were sampled by counting total thrips in each of 10 flowers/treatment (40 flowers total). Mature fruit (pink stage) were harvested weekly from 23 Aug to 20 Sep, and total number of fruit harvested and damaged by SB and TFW were recorded.

First Generation European Corn Borer Control, 1990

Abstract A cornfield near Delmont, S. Dak., was chosen to evaluate 22 compounds for control of first brood European corn borer (ECB) larvae. Preapplication counts indicated a uniform infestation of third instar, or younger, larvae in 80% of stalks sampled. Granules were applied to corn at whorl (1 wk prior to tasselling) stage of physiological development. Treatments included 11 granular, 10 liquid, and 3 untreated controls. Granular compounds were applied to single row plots (0.9 cm × 30.5 m) in a randomized complete block design with 4 replicates. Granules were directed into whorls of corn plants using a pneumatic applicator powered by a 3.5 horsepower engine attached to a highboy. Noble metering units mounted on a modified chain-driven apparatus regulated the amount of granules released into the applicator. Liquids were applied with a 3 gal C02 backpack sprayer. Approximately one month following application, 20 cornstalks were randomly chosen from each plot. Each plant was split vertically and examined for ECB tunnelling damage. The number and length of ECB cavities were recorded and analyzed.

Foliar Sprays on Late Planted Corn, 1989

Abstract Sweet corn was planted on 3 Jul near Georgetown, DE. Single row plots, 20 ft long on 30-inch centers, were replicated 4 times in a randomized complete block design. Treatments were applied with a CO2-pressurized backpack sprayer using 2 nozzles/row delivering 52 gal/acre at 40 psi. Silk sprays were applied on 5, 8, 12, 19, 21 and 25 Sep. At harvest maturity (27 Sep), all ears from each plot were husked and evaluated for damage as “fresh market” (clean ears, no damage evident) and “processing” (evidence of tip feeding, but less than 3.6 cm tip damage). All worms found were identified, counted and recorded.

Lepidopterous Larvae Control on Collards, 1988

Abstract ‘Vates’ collards were transplanted 3 May near Benson, NC. Single row plots, 10 ft long on 60 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft were used between replicates. Black plastic mulch and trickle irrigation were used in all plots. Treatments were applied with a CO2 pressurized backpack sprayer using a single hollow cone nozzle (18 x). Application rate was 54 gal/acre delivered at 60 psi, and Triton B-1956 spreader-sticker was used with all treatments. Applications were made 22 Jun, 1, 6, 14, 21 Jul, 3, 10, 17, and 25 Aug. Foliar damage ratings were made 12, 19, 26 Jul, 9, 16, 22, and 30 Aug. Counts of larvae on 3 plants/plot were made in the untreated check on all sampling dates after 12 Jul.

Insect Control on Staked Tomatoes, 1989

Abstract Six-week-old transplants were set on 3 Jul, at the Mountain Horticultural Crops Research Station, Fletcher, NC. Plants were set 2 ft apart within rows, and rows were on 10 ft centers. Single row plots (10 plants) were separated by cultivated alleyway, and treatments were replicated 4 times and arranged in a randomized complete block design. Insecticide treatments were applied on 8, 15, 22 and 29 Aug, and 5, 12 and 19 Sep, with a CO2 backpack sprayer operating at 60 psi and delivering 75-125 gal/acre (volume increased as plants grew) through 3 hollow-cone nozzles spaced 12 inches apart on the spray wand. Material was applied to both sides of rows so that each row was effectively treated with 6 nozzles/row. Potato aphid populations were monitored weekly from 14 Aug to 18 Sep, by recording the percent infested terminals (20 terminals/treatment). Mature fruit were harvested weekly from 13 Sep to 11 Oct, and the total number of fruit harvested and fruit damaged by lepidopterous pests (tomato fruitworm and cabbage looper) and SB (green and brown stink bug) was recorded.

Corn Earworm and European Corn Borer Control on Sweet Corn, 1988

Abstract Snowbelle’ sweet corn was planted on 25 May, near Benson, NC. Single row plots, 10 ft long on 42 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18X) operating at 60 psi to apply 80 gal/ acre. Treatments were initiated at early tassel stage, and were applied 18, 21, 23, 25, 27, 29 Jul, 1, 3, 5, 8, 10, 13, and 16 Aug. All mature ears in each plot were harvested 11 and 17 Aug and scored for larval damage. Counts were combined, and the percent damaged ears determined.

Colorado Potato Beetle Control, Pasquotank County, 1988

Abstract 'Atlantic' potatoes were planted 9 Mar, near Weeksville, NC. Single row plots, 10 ft long on 42 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18 × ) operating at 60 psi to apply 80 gal/acre. Treatments were applied 17 and 27 May. Visual estimates of foliar damage and/or insects counts were made 27 May and 9 Jun. Adults were counted by walking the length of the plot and counting all visible adults. Egg masses and larvae were counted on 3 hills/plot. Small larvae were estimated to be 1st and 2nd instars, and large 3rd and 4th. Potatoes were harvested and yields recorded on 9 Jun.

Cabbage Aphid and Webworm Control, 1988

Abstract ‘Early Jersey’ cabbage was transplanted 5 Aug near Benson, NC. Single row plots, 10 ft long on 60 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft were used between replicates. Trickle irrigation was used in all plots. Treatments were applied with a CO2 pressurized backpack sprayer using a single hollow cone nozzle (18 x). Application rate was 54 gal/ acre delivered at 60 psi, and Triton B-1956 spreader-sticker was used with all treatments. Applications were made 8, 14, 22, 30 Sep, 10 and 18 Oct. Insect counts or ratings were made 6 Oct, and quality ratings of heads which had formed and damage ratings of all plants were made 3 Nov.

Cherry Pepper, Corn Earworm and European Corn Borer Control, 1988

Abstract Sweet Red Cherry’ pepper was transplanted 18 May, near Benson, NC. Single row plots, 10 ft long on 60 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18 X) operating at 60 psi to apply 54 gal/ acre. Treatments were applied 23 Jun, 1, 7, 14, 21, 28 Jul, 4, 11, 18, 25 Aug, 2 and 13 Sep. When Orthene 75 SP and Asana XL were sprayed alternate weeks, Orthene was applied 23 Jun, 7, 21, 28 Jul, 11, 25 Aug and 13 Sep. Asana was applied on the remaining dates. Fruit was harvested 4, 11, 18, 25 Aug, 1, 12, and 21 Sep, and scored for earworm and corn borer damage. Counts were combined, and the percent damaged fruit determined.

Bell Pepper, Corn Earworm and European Corn Borer Control, 1988

Abstract Marengo’ pepper was transplanted 18 May, near Benson, NC. Single row plots, 10 ft long on 60 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18 x) operating at 60 psi to apply 54 gal/acre. Treatments were applied 23 Jun, 1, 7, 14, 21, 28 Jul, 4, 11, 18, 25 Aug, 2 and 13 Sep. When Orhtene 75 SP and Asana XL were sprayed alternate weeks, Orthene was applied the first time. Fruit was harvested 28 Jul, 4, 11, 18, 25 Aug, 1, 12, 21, and 23 Sep, and scored for earworm and corn borer damage. Counts were combined, and the percent damaged fruit determined.

Control on Sweet Corn, 1989

Abstract Sweet corn was planted on 4 May near Georgetown, DE. Single row plots, 20 ft long on 30-inch centers, were replicated 4 times in a randomized complete block design. Treatments were applied with a CO2-pressurized backpack sprayer using 2 nozzles/row delivering 52 gal/acre at 40 psi. Silk sprays were applied on 12, 14, 18, 21, 25 and 28 Jul. At harvest maturity (31 Jul), all ears from each plot were husked and evaluated for damage as “fresh market” (clean ears, no damage evident) and “processing” (evidence of tip feeding, but less than 3.6 cm tip damage). All worms found were identified, counted and recorded.

Sweetpotato Soil Insect Control, Lenoir County, 1988

Abstract 'Jewel' sweetpotatoes were transplanted 16 Jun near Kinston, NC. Single row plots, 20 ft long on 42 inch centers were replicated 4 times in a randomized complete block design. Preplant incorporated materials were applied immediately before transplanting, with either a CO2 pressurized backpack sprayer with a single flat fan nozzle or a shaker jar. Materials were incorporated 2 to 3 inches deep with a hand rake. Granular layby treatments were applied in an 18 inch band over the row on 2 Aug, with shaker jars. Visual estimates of plant vigor were made on 2 Aug. Sweet potatoes were harvested 28 Oct, and 25 roots/plot were evaluated for insect damage.

Colorado Potato Beetle Control, Johnston County, 1988

Abstract 'Atlantic' potatoes were planted 14 Apr, near Benson, NC. Single row plots, 10 ft long on 42 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized sprayer with a single hollow cone nozzle (18 × ) operating at 60 psi to apply 80 gal/acre. Treatments were applied 24 May (all treatments), 31 May (Trident, Trident + Nufilm, and M-One, 2 rates), 8 Jun (Trident, Trident + Nufilm, M-One, 2 rates, and Rotenox), 1 Jul (all), and 6 Jul (Trident, Trident + Nufilm, and M-One, 2 rates). Visual estimates of foliar damage and/or insects counts were made 30 May, 6, 13, 20, 27 Jun, 5, 11, and 25 Jul. Adults were counted by walking the length of the plot and counting all visible adults. Egg masses and larvae were counted on 3 hills/plot. Small larvae were estimated to be 1st and 2nd instars, and large 3rd and 4th. Potatoes were harvested and yields recorded on 25 Jul.

First Generation European Corn Borer Control, 1988

Abstract A corn field near Delmont, SD, was chosen for evaluating 29 European corn borer (ECB) treatments. On 5 May the crop was sown with a 38 inch row spacing. Preapplication counts indicated a uniform distribution of first-, second-, or third-instar ECB larvae in 30% of those corn stalks sampled. Treatments (2 untreated controls, 2 liquid, and 25 granular compounds) were established to evaluate their efficacy in controlling first brood ECB larvae. Granular compounds were applied on 18 Jun to single row plots (0.9 cm by 30.5 m) in a randomized complete block design with 4 replications. Granules were placed in the whorl of corn plants from a highboy using a pneumatic applicator powered by a 3.5 hp engine. Noble metering units were mounted on a modified chain driven apparatus which regulated the amount granular insecticide released. Liquid compounds were applied with a 3.0 gal COa backpack sprayer. Insecticide application rates were computed on a broadcast basis using a band width of 12 inches applied directly in the whorl. These rates may be different from those reported by other investigators where treatments are computed on a linear area basis (linear ft of row) to establish corn rootworm application rates. The broadcast application rates are approximately 0.33 of the rootworm application rates. At the 48th day postapplication, 20 corn stalks were randomly chosen from each plot. Plants were split vertically and examined for ECB tunnelling damage. The number and length of ECB cavities were recorded.