Christmas Tree Plantations Research Articles

Scotch Pine, Control of a Pine Needle Scale at Three Separate Developmental Stages, Wayne Co., Ohio, 1990

Abstract Scotch pine, 2-2.5 m tall, growing in a Christmas tree plantation in Wayne Co., OH, were used to evaluate insecticides against three separate stages of a pine needle scale: overwintering eggs, crawlers with some 1st stage nymphs, and new females prior to oviposition. Treatments were applied to overwintering eggs on 16 Apr under sunny skies, 15°C, and 16-24 km/h winds with 10.5 cm rainfall during this test period. On 7 May crawlers and settled 1st stage nymphs were treated under sunny skies, 23°C, and 24-32 km/h winds, with 5.33 cm rainfall during this test period. On 20 Jun new females were treated under cloudy skies, 18°C, and 8-16 km/h winds, with 2.3 cm rainfall during this test period. An Echo backpack mistblower operating at half-throttle on aperture setting # 3 for 25 s was used to deliver ca. 1260 ml of finished spray to each of the three, single-tree replicates per treatment. Dormant, over-wintering egg treatments were evaluated 18 May by removing three needle fascicles from each replicate tree and counting the number of non-parasitized (with chorion) females vs the number of live crawlers per fascicle. Crawler/lst stage nymph treatments were evaluated 18 May by removing five fascicles from each replicate tree and assessing percent mortality of scales present. Treatments to control new females were evaluated 2 Jul, using the same method.

Scotch Pine, Control of European Pine Sawfly, Wayne Co., Ohio, 1990

Abstract Scotch pine, 1.5-2 m tall, growing in a Christmas tree plantation in Wayne Co. were used to evaluate insecticides against European pine sawfly larvae. Treatments were applied 2 May when conditions were partly cloudy, 13°C, with 8-16 km/h winds. There were 3.1 cm of rainfall in the experimental area during the test period. Larvae were 6-12 mm long when sprays were applied. An Echo backpack mistblower operating at half-throttle on aperture setting #2 for 15 s was used to deliver ca. 300 ml of finished spray to each of 3, single-tree replicates. Sprays were directed toward colonies and surrounding foliage. Treatments were evaluated 8 DAT by counting the number of live larvae per colony.

Scotch Pine, Evaluation of Selected Insecticides Against European Pine Sawfly, Wayne Co., Ohio, 1989

Abstract Scotch pine, 1-1.5 m tall, growing in a Christmas tree plantation were used to evaluate insecticides against European pine sawfly larvae. Larvae were 15-20 mm in length when treatments were applied. Trees selected had at least one active colony of sawfly larvae. Sprays were applied 29 May under sunny skies, 15°C, and 8-16 km/h winds. The treatment area received 0.2 cm rainfall during the test period. A KWH backpack mistblower, operating at half throttle on aperature setting #3 for 15 s, was used to deliver 300 ml of finished spray to each of the 4 single-tree replicates/treatment. Sprays were directed toward a colony and surrounding foliage. Treatments were evaluated 3 DAT by counting the total number of live larvae per colony.

Scotch Pine, Pine Needle Scale Control, Wayne Co., Oh, 1988

Abstract Scotch pine (1.5-2 m tall) growing in a Christmas tree plantation were chosen for evaluating efficacy of insecticides against pine needle scale crawlers. Heavily infested trees were sprayed 18 May, when crawler hatch was 93%, using a KWH backpack mistblower operating at half throttle on aperture setting 3 for 30 s delivering ca. 600 ml of finished spray to each of 4, single-tree replicates/treatment. Skies were overcast, 13°c, with a 16-25 kph breeze. Light rain (less than 0.25 cm) occurred 2 h after sprays had dried. Treatment effectiveness was evaluated 1 Jun by collecting 5 needle fascicles from each replicate. Needles were placed in coin envelopes and transported in a cooler to the laboratory where viability of the first 100 crawlers for each sample was determined with the aid of a dissecting scope. Counts were made from all 5 needle fascicles (first 20 nymphs from tip of each fascicle).

Eastern Spruce Gall Adelgid Control, 1989

Abstract The experiment took place in a heavily infested spruce Christmas tree plantation in Plymouth, NH. Treatments were applied 16 May to the nymphal stage at budbreak. Plot size consisted of a sample tree, 4-6 ft in height randomly selected. Treatments were replicated 9 times. Treatments were applied with backpack hydraulic sprayer at 40 psi to the point of run off. Conditions at the time of spraying were: air temperature, 60°F; no wind; no precipitation for several days post treatment. Treatments were rated on 10 Oct by counting the number of new galls/tree.

Nantucket Pine Tip Moth Control in North Carolina, 1988

Abstract Two Christmas tree plantations of Virginia pines in Lenoir County, NC were selected to test 3 experimental insect growth regulators for efficacy. Three application rates each of RH-5849 and RH-5992, developed by Rohm and Haas Company, and 2 application rates of LAB 166 801 I, developed by BASF Corporation, were tested. RH-5849 and RH-5992 were applied with spreader-sticker triton B-1956 (4 oz/100 gal). Guthion and Dimilin were used as standards. Using a randomized block design, 3 blocks of 35 trees each in plantation I and 3 blocks of 25 trees each in plantation II were selected for treatments and controls. The trees were sprayed on 23 Jun in plantation I and 18 Aug in plantation II, 10 d after peak pheromone trap catch of adults, with a hand pump sprayer to the point of run-off. Each site was evaluated 5 wk after treatment. The dead terminals were examined for tip moth and counted on treated and untreated trees, using 3 center trees of each block in the evaluation.

Nantucket Pine Tip Moth Control in North Carolina, 1989

Abstract A Christmas tree plantation of Virginia pines in Wayne Co., NC was selected to test an experimental growth regulator for efficacy. RH-5992, developed by Rohm and Haas Company, was tested using 2 application rates and was applied with spreader-sticker triton B-1956 (4 oz/100 gal). Guthion and Dimilin were used as standards. Using a randomized block design, 4 blocks of 25 trees were selected for each treatment and controls. The trees were sprayed on 12 Apr, about 10 d after peak flight of adults, with a hand pump sprayer to the point of run-off. The trees were evaluated on 30 May, 7 wk after treatment. The dead terminals were examined for tip moth and counted on treated and untreated trees, using 3 center trees of each block in the evaluation.

A DRIS application to Fraser Fir Christmas Trees

Abstract A study developing a DRIS application to evaluate foliar nitrogen (N), phosphorus (P.), potassium (K), calcium (Ca), and magnesium (Mg) nutrition, was conducted on a 3‐year‐old Fraser fir [Abies fraseri(Pursh) Poir.] Christmas tree plantation in Watauga county, North Carolina. Preliminary DRIS norms and index equations were developed from premium grade Christmas trees for the five nutrients analyzed. In contrast to most crops where growth or yield are assessed. Fraser fir Christmas tree performance was evaluated by conventional grading procedures based on tree quality. Preliminary evaluation of DRIS performance on the 79‐tree data set suggested that assessments of nutritional balance as well as an examination of individual nutrient concentrations are needed to diagnose the nutrient status of Fraser Fir Christmas trees

Spruce Spider Mite Control on Fraser Fir, State College, 1987

Abstract Fraser fir (1-2 m high) growing at a Christmas tree plantation in State College, Pa., were used to evaluate acaricides against spruce spider mites. Treatments were assigned to heavily infested trees at random and consisted of 4 single-tree replicates. Pretreatment counts indicated 182 mites/single-tree sample. Treatments were applied with a KWH backpack mistblower operating at half throttle on setting 3 for 40 s, delivering 910 ml of finished spray/tree. The first application was made to all trees 21 May under cloudy skies, 18°C, and 8-16 km/h breeze. A second spray was applied to some of the trees 2 Jun under partly sunny skies, 27°C, and 0-16 km/h breeze. Treatments were evaluated 1, 2, 4, and 8 wk after the second application by removing four 10-15-cm-long lateral branch tips from each of the 4 replicates/treatment. Samples were transported in coolers or insulated boxes and shipped by overnite carrier. All samples were immediately processed by passing them through a mite brush 6 times to dislodge mites to a rotating glass plate coated with Tween 20. The number of live mites was counted with the aid of a dissecting microscope.

Spruce, Eastern Spruce Gall Adelgid Control, Salem, 1987

Abstract Norway spruce (0.5-1.0 m tall) growing in a Christmas tree plantation were used to evaluate insecticides against eastern spruce gall adelgids. Four single-tree replicates, each with at least 4 recent galls, were sprayed with each treatment. A KWH backpack mistblower operating at half throttle on setting 3 for 30 s delivered 946 ml of finished spray to each tree. Sevin 80 S was applied 1 Oct, when adelgids were active on twigs, but hatching was not complete. An additional treatment was applied 14 Oct, along with the other treatments, when hatching was complete. Conditions on both spray dates were sunny, 15-18°C, and 8-16 km/h breeze. Treatments were evaluated 12 Nov by randomly removing 4 8-12-cm-long, lateral branch tips having at least 1 gall for each of the 4 replicates/treatment. Samples were placed in plastic bags and transported in an ice chest to the laboratory. Samples were immediately processed with the aid of a dissecting microscope by assessing the percentage of twigs with galls having live adelgids near buds. All buds were examined for presence of adelgids.

Control of Pine Needle Scale, On Scotch Pine, Loudonville, 1987

Abstract Scotch pines (0.5-1 m tall), growing in a Christmas tree plantation in Loudonville, Ohio, infested with first-generation pine needle scales were chosen for evaluating efficacy of selected pesticides against scale crawlers. Spray applications were made 18 May using a KWH backpack mistblower operating at half throttle on aperture setting 3 for 30 s and delivering 600 ml of finished spray to each of 4 replicate trees/treatment. Conditions were sunny, 24°C, and 13-26 km/h breeze. Treatment effectiveness was evaluated at 8 and 13 DAT by collecting 5 needle fascicles from each tree. Needles were placed in coin envelopes and transported in a cooler to the laboratory, where viability of 100 crawlers for each sample was determined with the aid of a dissecting microscope. Counts were made from all 5 needle fascicles (first 20 nymphs observed on each).

Control of Second-Generation Pine Needle Scale, Burton, 1987

Abstract Scotch pines (1-2 m tall) growing in a Christmas tree plantation in Burton, Ohio, infested with pine needle scale were chosen for evaluating pesticides against scale crawlers. Sprays were applied 21 Jul using a KWH backpack mistblower operating at half throttle on aperture setting 3 for 30 s and delivering 600 ml of finished spray to each of 4 replicate trees/treatment. Conditions were sunny, 34°C, and 6-16 km/h breeze. Treatment effectiveness was evaluated at 13 DAT by removing 5 needle fascicles from each tree. Needles were placed in coin envelopes and transported in a cooler to the laboratory, where mortality was assessed with the aid of a dissecting microscope. Counts were made from all 5 needle fascicles (first 20 nymphs observed on each).

Control of Summer Generation Crawlers of a Pine Needle Scale on Scotch Pine, Carroll County, Ohio, 1981

Abstract Scotch pine (2-2.5 m high) growing in a Christmas tree plantation were chosen for evaluating toxicity of an experimental pyrethroid insecticide against crawlers of the summer (= July) generation. Infested trees with newly hatching crawlers were sprayed 22 Jul, using a KWH mistblower operating at maximum speed to deliver 946 ml of finished spray to each of 4 single-tree replicates/treatment. Ambient temperature was 21°C with partly cloudy skies and 6-8 km/h winds. Settled first instars, crawlers, and eggs were present during spraying. Treatment effectiveness was evaluated 4 Aug by collecting infested needle fascicles and inspecting them with the aid of a binocular microscope in the field for living and dead settled first instars. Counts were made from at least 31 needle fascicles; the first 100 settled nymphs observed were used for analysis.

Control of First Generation Crawlers of a Pine Needle Scale on Scotch Pine, Licking County, Ohio, 1985

Abstract Scotch pine (1.5-2 m tall) growing in a Christmas tree plantation were chosen for evaluating efficacy of insecticides against crawlers (5% settled first-stage nymphs). Heavily infested trees were sprayed 30 Apr using a KWH backpack mistblower operating at 0.5 throttle on aperature setting 3 for 30 s to deliver 600 ml of finished spray to each of 4 single-tree replicates/treatment. Conditions were sunny, 24°C, with 8-16 km/h winds. Treatment effectiveness was evaluated 10 May by collecting infested needles from at least 3 locations on each tree. Needles were placed in coin envelopes and transported in a cooler to the laboratory, where viability of the first 100 crawlers observed under a dissecting microscope was determined. Counts were made from at least 3 needle fascicles.

Pine Tortoise Scale Control on Scotch Pine, Carroll County, Ohio, 1986

Abstract Scotch pine (1-2 m high) growing in a Christmas tree plantation were used to evaluate efficacy of selected insecticides against pine tortoise scale. Infested trees were sprayed 25 Apr using a KWH backpack mistblower operating at aperture setting 4 delivering 1200 ml of finished spray/tree. Sprays were applied to each of the 3 single-tree replicates/treatment when scales were mature (4.3 mm diameter). Conditions while spraying were sunny, 23-25°C, with winds at 16-23 km/h. Treatment effectiveness against mature scales was evaluated 9 May by removing 3 infested twigs from each tree and assessing percent mortality with the aid of a dissecting microscope. Residual impact of treatment on crawler establishment was evaluated 23 Jun by removing 5 needle fascicles near the twigs infested with mature scales from each tree and counting the number of live crawlers with the aid of a dissecting microscope.

Dormant Application of Selected Insecticides on Scotch Pine for Controlling Pine Tortoise Scale, Mont-Gomery County, Ohio, 1985

Abstract Scotch pine (1-2 m high) growing in a Christmas tree plantation were used to evaluate efficacy of insecticides against mature scales. Infested trees were sprayed 26 Mar, using a COa compression sprayer at 40 psi with a single Teejet SS8004 flat-fan nozzle delivering sprays to run-off. Sprays were directed toward the infested limbs of each of 4 single-tree replicates/treatment. Conditions while spraying were sunny at 7-10°C with winds of 16-23 km/h. Treatment effectiveness was evaluated 9 Apr by removing 3 infested twigs from each tree and evaluating mortality using a dissecting microscope.

Insecticide Sprays for Control of the Northern Pine Weevil in Southern Illinois

The northern pine weevil, Pissodes approximates, is a serious pest in Christmas tree plantations where harvesting of trees has occurred and where seedling trees have been planted. During the spring months the immature stages of the weevil develop in stumps from trees harvested during the previous November or December. When the adult weevils emerge during May and June they feed on seedling trees causing high mortality. Excellent control resulted from a carbofuran spray applied March 12, 1985 onto Scots pine boles in southern Illinois.

Control of Pine Needle Scale on Scotch Pine, Wayne County, Ohio, 1986

Abstract Scotch pine (2-3 m tall) infested with pine needle scale growing in an abandoned Christmas tree plantation were chosen for evaluating efficacy of selected insecticides against scale crawlers. A flag was placed near the highest density of scale for each tree; sprays were applied to that area 6 May, using a KWH backpack mistblower operating at 0.5 throttle on aperture setting 3 for 45 s, delivering 930 ml of finished spray to each of 4 replicate trees/treatment. Conditions were cloudy, 24°C, with 16-32 km/h winds. Treatment effectiveness was evaluated 7, 13, and 28 days posttreatment by removing 5 needle fascicles from at least 3 locations within each sprayed area of each tree. N'eedles were placed in coin envelopes and transported in a cooler to the laboratory, where percent mortality was assessed with the aid of a dissecting microseope.

Balsam Woolly Adelgid Control, 1986

Abstract A study was conducted in July and August to compare the efficacy of 2 insecticide treatments for Balsam woolly adelgid (BWA) control. A Fraser fir Christmas tree plantation near Cullowhee in Jackson County, N.C., was selected as the study site. Using a 2.5-gal hand-pressurized portable sprayer, each insecticide treatment was replicated 6 times (1 tree/replicate) by spraying the entire main stem of 6- to 7- ft-tall fir trees until runoff. Four control trees received water sprays only. Pretreatment counts were taken on 3 Jul by removing 2 circular disks of bark from the bole of each tree using a no. 8 cork borer. Disks were taken from the most heavily infested bark areas. In the same manner, posttreatment counts were taken at 2 and 6 wk after treatment. All BWA life stages (both living and dead) were counted/disk, and mean live posttreatment population densities and % live BWA density changes were determined.

Spruce Spider Mite Control, 1986

Abstract A study was conducted in August to compare the efficacy of 3 formulations of Zectran mexacarbate insecticide for spruce spider mite (SSM) control. Pydrin insecticide was used as a comparison standard. A Fraser fir Christmas tree plantation near Cullowhee in Jackson County, N.C., was selected as the test site. Using a 2.5-gal hand-pressurized portable sprayer, the foliage and main stem of 2 SSM-infested fir trees (6-7 ft tall) per treatment were sprayed until wet. Two control trees received water sprays only. Ten to 12 trees could be sprayed per gal. Treatments were applied in a completely random design. Pretreatment counts were taken on 1 Aug by clipping 5 5-cm-long SSM infested twigs (1 twig/replicate) from each tree. All live SSM life stages were counted, and the mean density per 5 cm twig was determined. In the same manner, posttreatment counts were taken 2 wk after treatments and compared to corresponding pretreatment counts to determine % live SSM density changes.