- COLLARDS -

COLLARD:  Brassica oleracia L.,  ‘Champion’                 

2001

COLLARDS

EVALUATION OF FURY FOR CONTROLLING FOLIAR INSECT PESTS ON LEAFY GREENS, OKLAHOMA, 2001: 

Collard seeds were planted 11 May at the Wes Watkins AREC, Lane, OK.  The experimental design was a randomized complete block with five treatments and five replicate blocks with plots on 6-ft row spacing and two rows of plants 10 inches apart in each plot, 15 ft long and with 15-ft alleys between plots.   Plots were treated on 5, 13 and 18 Jul using a tractor-mounted sprayer with three hollow-cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy.  The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were examined approximately four days after each treatment and number of green peach aphid (GPA) and cabbage looper (CL) larvae recorded.  Plant damage was determined on 17 Jul by examining the terminal five leaves on three plants per plot for evidence of feeding by caterpillars and grasshoppers as evidenced by chewing type holes in leaves.   The total number of leaves with chewing type feeding damage was recorded.  Data were summarized and analyzed using ANOVA and treatment effects were compared using a LSD test for data for each variable with data summed across survey dates.

GPA and CL larvae were moderately abundant.   Each insecticide or insecticide combination provided significant reductions in CL densities in comparison to densities in the untreated plots.  Applications of Capture significantly reduced GPA densities in comparison to the untreated plots.  Each treatment with the exception of Lepinox alone resulted in significant reductions in numbers of leaves with feeding damage.  Lepinox has specific activity for lepidoptera species and was not expected to control grasshoppers that caused a portion of the leaf feeding damage.  However, Fury and Capture are both broad spectrum activity pyrethroid insecticides with activity against lepidoptera and grasshoppers and therefore were expected to provide control of both types of leaf feeding pests.   Applications of Fury and Capture did result in significant reductions in leaf damage due to leaf chewing insects.

1 Mean number per 3 plants per survey date.

2 Mean number of damaged leaves / 5 leaves per plant.

Numbers in a column followed by different lower case letters are significantly different (LSD, P=0.1).

COLLARDS

EVALUATION OF NOVALURON FOR CONTROLLING INSECT PESTS ON LEAFY GREENS, OKLAHOMA, 2001

Cabbage lopper (CL):  Trichoplusia ni (Hubner).                   

Grasshoppers:  unknown species                                    

Collard seeds were planted 11 May at the Wes Watkins AREC, Lane, OK.  The experimental design was a randomized complete block with 10 treatments and five replicate blocks with plots 6-ft wide and two rows of plants 3-ft apart in each plot.  Plots were 15 ft long with 15-ft alleys between plots.   Plots were treated on 5, 13 and 18 Jul using a tractor-mounted sprayer with three hollow-cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy.  The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were examined approximately 4-5 days after each treatment and number of CL larvae recorded.  Plant damage was determined on 17 Jul by examining the terminal 5 leaves on three plants per plot for evidence of feeding by caterpillars and grasshoppers as evidenced by chewing type holes in leaves.   The total number of leaves with chewing type feeding damage was recorded.  Data were summarized and analysed using ANOVA and treatment effects compared using a LSD test for data for each variable on individual survey dates with data summed across survey dates.

CL pressure was moderate throughout the evaluation period.  Novaluron at the two higher rates, Intrepid, Avaunt, Proclaim and Warrior applications resulted in significantly reduced abundance of CL after a single application as indicated by surveys on 10 Jul.  Each insecticide application resulted in reduced densities of CL after the second application as indicated by surveys on 17 Jul.  Population densities of CL were in decline in the untreated plots on 24 Jul and applications of Novaluron and Intrepid resulted in significantly reduced abundance of CL.  When data for density of CL was summed across dates results indicated that each of the insecticides provided significant reductions in CL abundance through the season.  Counts of damaged leaves indicated that each insecticide resulted in reductions in number of damaged leaves in comparison to the untreated plots.  The two high rates of Novaluron and Proclaim resulted in significantly reduced numbers of damaged leaves in comparison to the low rates of Novaluron, Intrepid and Avaunt.  Leaf damage resulted from feeding by CL and grasshoppers and thus indications are that the higher rates of Novaluron and Proclaim in contrast to Intrepid and Avaunt resulted in reductions in grasshopper feeding in addition to controlling CL. 

                                                Cabbage looper larvae / 3 plants 

Means in a column followed by the same lower case letter are not significantly different, LSD, P=0.1.

Results expressed as mean number of CL / 3 plants and number of damaged leaves / 5 terminal leaves per plant.

COLLARDS

INSECTIDE EFFICACY FOR CONTROLLING INSECTS ON LEAFY GREENS, OKLAHOMA, 2001

Green peach aphid (GPA); Myzus persicae (Sulzer)                      

Cabbage lopper (CL); Trichoplusia ni (Hubner).                   

Grasshoppers:  unknown species                                    

Collard seeds were planted 11 May at the Wes Watkins AREC, Lane, OK.  The experimental design was a randomized complete block with six treatments and five replicate blocks with plots on 6-ft row spacing and two rows of plants 10 inches apart in each plot, 15 ft long and with 15-ft alleys between plots.   Plots were treated on 5, 13 and 18 Jul using a tractor-mounted sprayer with three hollow-cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy.  The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were examined approximately four days after each treatment and number of GPA and CL larvae recorded.  Plant damage was determined on 17 Jul by examining the terminal five leaves on three plants per plot for evidence of feeding by caterpillars and grasshoppers as evidenced by chewing type holes in leaves.   The total number of leaves with chewing type feeding damage was recorded.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable with data summed across survey dates.

GPA were moderately abundant throughout the evaluation period.  Each of the insecticide applications with the exception of Baythroid provided significant reductions in GPA density in comparison to the untreated plots.  Leverage is a mixture of Baythroid and imidacloprid and provided similar reductions of GPA as imidacloprid alone.  Thiamethoxam, acetameprid and imidacloprid belong to the neonicotinoid insectidide group and when applied as foliar sprays provided similar control of GPA as measured by reductions in density in comparison to the untreated plots.  Baythroid and Leverage applications resulted in reduced damage to leaves in comparison to each of the other insecticide application treatments and the untreated plots.  This reduction was probably due to the activity of the pyrethroid insecticide, Baythroid, in controlling CL and grasshoppers that caused the chewing feeding type damage to leaves.

Means in a column followed by different lower case letters are significantly different, LSD, P=0.1.

1 Mean number of GPA per three plants averaged across survey dates.

2 Mean number of damaged leaves from terminal five leaves per plant on 17 Jul.

COLLARD:  Brassica oleraceae L.  ‘Champion’

APHID CONTROL ON LEAFY GREENS, FALL, 2002

Green peach aphid (GPA):  Myzus persicae (Sulzer)                      

Collard seeds were planted 21 Aug at the Wes Watkins AREC, Lane, OK.  The experimental design was a RCB with six treatments and five replicate blocks with plots on 6-ft row spacing and two rows of plants 10 inches apart in each plot, 15 ft long and with 15-ft alleys between plots.   Plots were treated on 4 and 14 Oct using a tractor-mounted sprayer with three hollow-cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy.  The sprayer was operated at 40 psi and delivered 20 gpa.  Aphids on one plant per plot were counted and recorded on each survey date.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable.

Aphids were abundant and the population was stable throughout the study period.  Each insecticide treatment resulted in reduced numbers of aphids in comparison to the untreated plants.   The initial application of insecticides resulted in decreased numbers of aphids at six days after application.  A second application of insecticides resulted in additional reductions in populations for each insecticide treatment.  Applications of Actara resulted in 99% control in comparison to the untreated plants.

Table 1.

                                                                        Mean number of aphids/plant             

Treatment                     Rate                             10 Oct             16 Oct             18 Oct

acetameprid                  0.1 lb ai / acre              36  b               49  b               20  b

Calypso                        6 oz / acre                    25  b                8  bc                5  b

flonicamid                     0.088 lb ai / acre           31  b              12  bc                2  b

zetacypermethrin          0.025 lb ai / acre           12  b                 8  bc                6  b

Actara  25WG              4 oz / acre                   18  b               0.8   c              0.6 b

Untreated                     -                                   170 a             154 a               134 a  

Means in a column followed by different lower case letters are significantly different, LSD, P=0.1.

COLLARD:  Brassica oleraceae L.  ‘Champion’

CONTROLLING LEPIDOPTERA LARVAE ON LEAFY GREENS, SUMMER, 2002

Diamond back moth (DBM):  Plutella xylostella (L.)

Cross-striped cabbageworm (CSW):  Evergestis rimosalis (Guenee)

Cabbage looper (CL):  Trichoplusia ni (Hubner)

Collard seeds were planted 26 Apr at the Wes Watkins AREC, Lane, OK.  The experimental design was a RCB with seven treatments and five replicate blocks with plots on 6-ft row spacing and two rows of plants 10 inches apart in each plot, 20 ft long and with 15-ft alleys between plots.   Plots were treated on 2 Aug using a sprayer with five hollow-cone nozzles spaced 18 inches apart.  The sprayer was operated at 40 psi and delivered 20 gpa.  Five plants per plot were visually inspected four days after application of insecticides.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable.

A mix species population of lepidoptera pest larvae was present and feeding on plants in August.  A single application of insecticides significantly reduced abundance of the total number of larvae of all species.  Spinosad and Baythroid were the only insecticides that resulted in significant reductions of DBM in comparison to the untreated plots.  Indications are that each of the insecticides has activity and can be used to control this complex of lepidoptera larvae on collards.

Table 1.

                                                                        Mean number of larvae per 5 plants   

Treatment            Rate                             DBM            CL                   CSW               Total

endosulfan         0.75 lb ai / acre            1.2 ab            1.0  b            0.2  b               2.4  b

naled                1.0 lb ai / acre               1.2 ab            0.4  b            0.8 ab              2.4  b

spinosad           1.07 lb ai / acre             1.0   b            0.4  b            0.2   b              1.6  b

l-cyhalothrin      0.03 lb ai / acre             1.2 ab            0.8  b            0.6   b              2.6  b

Baythroid 2E     2.8 fl oz / acre               1.0   b            2.0  b            0.6   b              3.8  b

Avaunt WDG    3.5 oz / acre                  2.2 ab            0.4  b            0.6   b              3.2  b

Untreated            --                                3.2 a            5.4 a            2.2 a                11  a

Means in a column followed by different lower case letters are significantly different, LSD, P=0.1.

COLLARDS: Brassica oleraceae L., “Champion’

EFFICACY AND RESIDUAL EFFECT OF INSECTICIDES FOR MANAGING DIFFERENTIAL GRASSHOPPER IN LEAFY GREEN VEGETABLES, 2001

Differential grasshopper:   Melanoplus differentialis (Thomas)

Third instar differential grasshoppers were collected from a pasture in southeast Oklahoma.  Grasshoppers were held in a laboratory at the Wes Watkins AREC, Lane, OK with a 14 h photo- period at 26 ± 0.5°C and fed with fresh collard leaves. Collard seeds were planted in a field on 16 May at the Wes Watkins AREC. The experimental design was a RCB with eight treatments and five replicate blocks with plots on  1.8 m  row spacing and two rows of plants 0.9 m apart in each plot. Plots were  6 m long with a gap of 4.5 m  between plots.  Plots were  treated on 06 Jul using a tractor mounted sprayer with three hollow cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy. The spray solutions were delivered at 332 liter/ha with a sprayer pressure of 28,122 kg/m².  Third instar grasshoppers were held without food for 24 hours and then placed in wire-meshed cages.   Cages were placed in plots by inserting one intact leaf at one end and the cages closed by tying the distal end closed.   A set of cages were placed in plots just before treatment, and another set placed in plots 24 hours after treatment. Mortality of grasshoppers in cages was recorded 24 hours after treatment and after a ten-day period. There was no rainfall recorded during the ten-day period.   Grasshoppers were noted as dead if they were immobile and did not respond to a slight shake of the cage.

Grasshoppers in cages placed on plants prior to treatment were subject to direct contact of the insecticides.   One day after treatment, mortality of grasshoppers was significantly greater in plots treated with Spintor, Thiodan, Dibrom and Asana in comparison to the untreated control (Table 1).  Ten days after applications there was significantly greater mortality in plots treated with all insecticides except Neemix in comparison to the untreated control plots.  Grasshoppers in cages placed on plants 24 hours after application were exposed only to residues of insecticides on leaves (Table 2).  There was no significantly increased mortality in plots receiving any of the treatments 24 hours after placement of the cages.  After ten days there were significant levels of mortality in plots treated with Spintor in comparison to the untreated control plots.  Several of the evaluated insecticides provided control of grasshoppers exposed to direct contact of the insecticides or to residues less than 24 hours old.  Only Spintor provided significant control when grasshoppers were exposed to residues greater than 24 hours old.
TABLE 1.

                                    Mean  Number Dead Grasshoppers/Cage placed prior to treatment

Treatment                        Rate kg AI/ha                        Day 1                        Day 10            

Untreated                           ---                              0.0  c                        0.0  e

Spintor 2SC                       0.175                         1.0  a                        1.0  a

Dimilin 2L                         0.07                            0.0  c                        0.4  cd

Neemix 4.5                       0.048                          0.0  c                        0.0 e

Thiodan 3EC                     1.118                         0.6  b                        0.6  bc

Dibrom8                           2.102                         1.0  a                        1.0  a

Asana XL                         0.055                         0.8  ab                        0.8  ab

Mycotrol                          0.179                         0.0  c                          0.2  de            

Numbers in a column are not significantly different if followed by the same letter (LSD, P = 0.1).

TABLE 2.

                                   Mean  Number Dead Grasshoppers/Cage placed after treatment

Treatment                        Rate kg AI/ha                        Day 1                        Day 10            

Untreated                                 ---                        0.0  a                        0.0  b

Spintor 2SC                        0.175                         0.0  a                        0.8  a

Dimilin 2L                             0.07                        0.0  a                        0.2  b

Neemix 4.5                         0.048                        0.0  a                        0.2  b

Thiodan 3EC                      1.118                        0.0  a                        0.0  b

Dibrom8                             2.102                        0.0  a                        0.0  b

Asana XL                           0.055                        0.0  a                        0.0  b

Mycotrol                            0.179                        0.0  a                        0.0  b              

Numbers in a column are not significantly different if followed by the same letter (LSD, P = 0.1).

COLLARDS: Brassica oleraceae L., ‘Champion’

EFFICACY OF INSECTICIDES FOR MANAGING DIFFERENTIAL GRASSHOPPER IN LEAFY GREEN VEGETABLE CROPS, 2002

Differential grasshopper; Melanoplus differentialis (Thomas)

Third instars of differential grasshoppers were collected from a pasture in south east Oklahoma and held in a laboratory at the Wes Watkins AREC, Lane, OK.  Insects were maintained in cages at a 14 h photo- period and 27 ± 0.5°C and fed with fresh collard leaves. Collard seeds were planted in a field on  25 Apr at the Wes Watkins AREC. The experimental design was a CRD with eight treatments and five replications  with plots on  1.8 m  row spacing and two rows of plants 0.9 m apart in each plot. Plots were  6 m long with a gap of 4.5 m  between each.  Plots were  treated on 20 Jun using a tractor mounted sprayer with three hollow cone nozzles per row, one directed over the row and one on each side of the row on drops directed at an angle to direct the spray up and into the plant canopy. The spray solutions were delivered at 332 litre/ha with the sprayter operating at 28,122 kg/m².  Third instar grasshoppers were removed 24 hours prior to evaluations and starved.  One grasshopper was placed in a wire-meshed cage and  placed in each plot.   An intact leaf on a plant was inserted at one end and the distal end of the caged tied closed. Cages were placed on plants in plots just before treatment, one hour after treatment and at twenty four hours after treatment.  Grasshoppers in cages were monitored for mortality at 24 hours after treatment and daily thereafter for a ten day period. There was no rainfall recorded during the ten day period.   Grasshoppers were noted as dead if they were immobile and did not respond to a slight shake of the cage. 

            More grasshoppers exposed to direct contact of insecticides in cages placed on plants prior to treatment were killed by Spintor, Thiodan, Dibrom and Asana within one day of treatment (Table 1).  After ten days, more grasshoppers exposed to direct contact of insecticides were killed with treatments of Spintor, Dimilin, Neemix, Thiodan, Dibrom and Asana compared to the untreated control plots.  For cages placed on plants within one hour after treatment there was no significant mortality of grasshoppers after 24 hours after placement of cages (Table 2).  After 10 days the one-hour residues of all insecticides had killed significant numbers of grasshoppers with the exception of the plots treated with Mycotrol.   In those cages placed on plants 24 hours after treatment there was no notable mortality of grasshoppers within 24 hours of placement of the cages (Table 3).  However, after 10 days exposure, more grasshoppers in the plots treated with Dimilin, Neemix, Thiodan and Asana had died compared with the untreated control plots.  Dibrom, Thiodan, Asana and Spintor applications resulted in quick knockdown of grasshoppers when they were exposed to direct contact of insecticides.   Long-term significant residual activity was provided by the two growth regulator insecticides, Neemix and Dimilin.

TABLE 1.

                                    Mean  Number Dead Grasshoppers/Cage placed prior to treatment

Treatment                        Rate kg AI/ha                        Day 1                        Day 10            

Untreated                                  ---                        0.0  c                        0.0  b

Spintor 2SC                        0.175                         0.4  b                        0.8  a

Dimilin 2L                               0.07                        0.0  c                        0.8  a

Neemix 4.5                           0.048                        0.0  c                        0.8  a

Thiodan 3EC                        1.118                        1.0  a                        1.0  a

Dibrom8                               2.102                        1.0  a                        1.0  a

Asana XL                             0.055                        0.6  b                        0.8  a

Mycotrol                              0.179                        0.0  c                        0.2  b              

Numbers in a column are not significantly different if followed by the same letter (LSD, P = 0.1).

TABLE 2.

                               Mean  Number Dead Grasshoppers/Cage placed 1 hour after treatment

Treatment                        Rate kg AI/ha                        Day 1                        Day 10            

Untreated                                   ---                           0.0  b                          0.0   c

Spintor 2SC                           0.175                           0.2  ab                       0.6  ab

Dimilin 2L                               0.07                            0.0  b                         0.8  a

Neemix 4.5                             0.048                          0.0  b                         0.4  abc

Thiodan 3EC                          1.118                          0.4  a                          0.4  abc

Dibrom8                                 2.102                          0.2  ab                       0.4  abc

Asana XL                               0.055                          0.2  ab                       0.8  a

Mycotrol                                 0.179                          0.0  b                        0.2  bc            

Numbers in a column are not significantly different if followed by the same letter (LSD, P = 0.1).

TABLE 3.

                            Mean  Number Dead Grasshoppers/Cage placed 24 hours post treatment

Treatment                        Rate kg AI/ha                        Day 1                        Day 10            

Untreated                                         ---                        0.0  b                        0.0  c

Spintor 2SC                               0.175                         0.0  b                        0.0   c

Dimilin 2L                                      0.07                        0.0  b                        0.8  a

Neemix 4.5                                 0.048                        0.0  b                        0.4   b

Thiodan 3EC                               1.118                        0.0  b                        0.2  bc

Dibrom8                                      2.102                        0.0  b                        0.0  c

Asana XL                                    0.055                        0.2  a                        0.2  bc

Mycotrol                                     0.179                        0.0  b                        0.0  c              

Numbers in a column are not significantly different if followed by the same letter (LSD, P = 0.1).

COLLARD:  Brassica oleraceae L.  ‘Champion’

HARLEQUIN BUG AND CABBAGE LOOPER CONTROL ON COLLARDS, 2003

Harlequin bug (HB):  Murgantia histrionica (Hahn)

Cabbage looper (CL):  Trichoplusia ni ( Hubner)

Collard seeds were planted during May at the Wes Watkins AREC, Lane, OK.  The experimental design was a RCB with eight treatments and five replicate blocks with plots on 6 ft row spacing and two rows of plants 10 inches apart in each plot, 20 ft long and with 15 ft alleys between plots.   Plots were treated 9 and 23 Jun and 1 Jul using a tractor-mounted sprayer with a single nozzle over the top of each row and nozzles on drops to each side of the row of plants.   The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were visually inspected 17 and 26 Jun and 11 Jul.  Plant damage was assessed one time at plant maturation by examining the five terminal leaves on three plants per plot and recording number of leaves with damage.  Leaves were noted as damaged if necrotic spots from HB feeding or holes from chewing insects were present on the leaf.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable.

HB nymphs and adults were abundant throughout the trial period and CL exceeded threshold tolerances on 11 Jul.  Dinotefuron at both rates, novaluron at the low rate and Mustang at the high rate provided significant reductions in HB populations throughout the trial in comparison to the untreated plots.  Novaluron applications reduced CL populations on 11 Jul in comparison to the untreated plots.  All insecticide applications resulted in significant reductions in damaged number of leaves in comparison to the untreated plots.

Table 1.

                                                                       CL /                       Damaged

                                              HB / 3 plants                          3 plants                       leaves

Treatment                   Rate/ acre            17 Jun            26 Jun            11 Jul            11 Jul            11 Jul

dinotefuron 20SC      5.25 oz                  4.8  b             0.0  c            5.7   d           2.0  bcd           2.5  b

dinotefuron 20SC        7.0 oz                  1.6  b             0.0  c            6.3   d            2.4 abc            3.0  b

novaluron                  0.04 lb (AI)           3.4  b              0.8  c          21.1  bc           0.9  de             2.8  b

novaluron                  0.05 lb (AI)          12.4 a              0.0  c           33.4 ab           1.4  cde            2.9  b

novaluron                 0.08 lb (AI)           12.0 a            13.0  b           26.7 ab           0.5  e               2.7  b

z-cypermethrin        0.018 lb (AI)          2.0  b               1.8  c           35.5 ab           3.1 a                2.9  b

z-cypermethrin        0.025 lb (AI)          1.0  b               0.0  c           13.7  cd          3.0 ab              2.5  b

Untreated                       --                  11.4 a              31.8 a            46.3 a             2.7 ab              4.1 a

Mean values in a column followed by different letters are significantly different, LSD, P=0.1.

COLLARD:  Brassica oleraceae L.  ‘Champion’

COMPARISON OF NICOTINOID INSECTICIDES FOR CONTROLLING HARLEQUIN BUG, 2003

Harlequin bug (HB):  Murgantia histrionica (Hahn)

Green peach aphid (GPA):  Myzus persicae (Sulzer)

Collard seeds were planted during May at the Wes Watkins AREC, Lane, OK.  The experimental design was a RCB with nine treatments and five replicate blocks with plots on 6 ft row spacing and two rows of plants 10 inches apart in each plot, 20 ft long and with 15 ft alleys between plots.   Plots were treated 9 and 23 Jun and 1 Jul using a tractor-mounted sprayer with a single nozzle over the top of each row and nozzles on drops to each side of the row of plants.   The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were visually inspected 25 Jun.  Plant damage was assessed one time at plant maturation by examining the five terminal leaves on three plants per plot and recording number of leaves with damage.  Leaves were noted as damaged if necrotic spots from HB feeding or holes from chewing insects were present on the leaf.  One terminal treated leaf per plot was collected on 11 Jun and taken to the lab where approximately 10 apterous GPA were placed on leaf disks cut from the leaves.  Leaf disks were maintained at 75^o F and GPA mortality recorded after 48 hr.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable.

Harlequin bugs were abundant throughout the period of time that the trial was conducted.  Aphid and lepidoptera pest populations were low.  All insecticides provided significant levels of control of HB in comparison to the untreated plots.  Acetameprid, Fulfill and zetacypermethrin treated leaves had significantly reduced levels of insect feeding damage.  Results from the bioassay with GPA indicated that leaves treated with acetameprid, thiamethoxam, Provado, Fulfill and zetacypermethrin resulted in significantly higher levels of GPA mortality than untreated leaves.  Results indicate that each of the insecticides should provide good to excellent control of sucking insect pests, both bugs and aphids as indicated by results with HB and GPA.

Table 1.

                                                                                    HB/3 plants            HB/5 leaves

Treatment                                 Rate / acre                  25 June            9 July              

acetameprid                              0.1 lb (AI)                  3.0  bc             4.0  b

flonicamid, 50 DF                   0.088 lb (AI)               2.0  bc             3.0  b

thiamethoxam                           0.06 lb (AI)                0.0   c              0.1 b

thiacloprid                                0.1 lb (AI)                  0.0   c              0.1 b

clothianidan                              0.10 lb (AI)               14   b               0.7 b

Provado 1.6F                           3.75 oz                     2.0  bc             0.7 b

Fulfill 50WG                             2.75 oz                     4.0  bc             1.3 b

zetacypermethrin                      0.025 lb (AI)              0.0   c              0.2 b

untreated                                  -                                   32 a                 32 a                

Mean values in a column followed by the different letters are significantly different, LSD, P=0.1.

Table 2.

                                                                        Damaged leaves   GPA assay

Treatment                                 Rate / acre                  9 July               % Mortality         

acetameprid                              0.1 lb (AI)                  2.5  bcd           56 a

flonicamid 50 DF                   0.088 lb (AI)                 3.4 ab              35 ab

thiamethoxam                           0.06 lb (AI)                3.1 ab              59 a

thiacloprid                                0.1 lb (AI)                  3.0 ab              36 ab

clothianidan                              0.10 lb (AI)                3.6 a                35 ab

Provado                                   3.75 oz                      2.7  bc             47 a

Fulfill                                        2.75 oz                      1.9   cd            43 a

zetacypermethrin                      0.025 lb (AI)              1.7   d              46 a

untreated                                  -                                3.4 a                11  b               

Mean values in a column followed by the different letters are significantly different, LSD, P=0.1.

COLLARD:  Brassica oleraceae L.  ‘Champion’

HARLEQUIN BUG CONTROL ON COLLARDS, 2003

Harlequin bug (HB):  Murgantia histrionica (Hahn)

Green peach aphid(GPA):  Myzus persicae (Sulzer)

Collard seeds were planted during May at the Wes Watkins AREC, Lane, OK.  The experimental design was a RCB with 11 treatments and five replicate blocks with plots on six ft row spacing and two rows of plants 10 inches apart in each plot, 20 ft long and with 15 ft alleys between plots.   Plots were treated 25 and 30 Jun and 8 Jul using a tractor-mounted sprayer with a single nozzle over the top of each row and nozzles on drops to each side of the row of plants.   The sprayer was operated at 40 psi and delivered 20 gpa.  Three plants per plot were visually inspected 27 Jun, and 2, 7, 12, and 17 Jul.  Plant damage was assessed one time at plant maturation by examining 1 terminal leaf on each of 10 plants per plot and recording number of leaves with damage.  Leaves were noted as damaged if necrotic spots from HB feeding or holes from chewing insects were present on the leaf.  Data were summarized and analyzed using ANOVA and treatment effects compared using a LSD test for data for each variable.

HB adults and nymphs were abundant throughout the trial.  Baythroid, fenpropathrin, Warrior and DE-225 treated plots had significantly fewer HB than untreated plots throughout the trial.  On the last date of surveys and after 3 applications of insecticides all treatments resulted in reduced numbers of HB in comparison to the untreated plots with the exception of buprofezin and methoxyfenozide both of which are most active against lepidopteran species.  GPA were abundant during the latter stages of the trial and surveys on 17 Jul indicated that Baythroid, fenpropathrin, Warrior, DE-225 and the high rate of Spintor resulted in reduced numbers of aphids in comparison to the untreated plots.  HB caused heavy damage levels to all plants because they were so abundant and plant damage ratings on 20 Jul indicated that applications of  Baythroid, fenpropathrin, Warrior, DE-225 and the high rate of Spintor resulted in reduced damage levels in comparison to the untreated plots.

Table 1.

                                                                        HB / 3 plants                                        

Treatment                      Rate /acre     27 Jun            2 Jul             7 Jul            12 Jul            17 Jul  

Baythroid 2E                2.8 fl oz         0.4 b            1.6 cd             15 abc          2.8 c           13 bcd

fenpropathrin                0.3 lb (AI)     0.2 b            0.0 e                2  c             1.2 c            9.0 cd 

buprofezin                    0.38 lb (AI)    7.4 a           6.6 ab             22 ab            10  b           23 ab  

Proclaim 5%WDG       4.8 oz            7.0 a            7.4 ab            20 ab            8.0 bc          16 bc  

methoxyfenozide          0.2 lb (AI)     11 a              9.2 a              20 ab           7.0 bc           20 ab  

Knack                         10 fl oz           5.4 ab          8.4 ab            26 a             4.0 bc           15 bcd

Warrior T                     3.8 fl oz         0.2 b            2.2 de             5 ab            1.8 c             8.0 cd 

Spintor 2SC                 4 fl oz            7.8 a            7.2 ab            25 ab            7.6 bc           15 bcd

Spintor 2SC                 6 fl oz            8.4 a            4.4 bc           17 abc            10  b            7.6 cd 

DE-225 5.9% F          3.8 fl oz         1.2  b            0.8 de           10 bc             5.8 bc          4.6 d   

Untreated                     --                  8.8 a            10 a               30 a               24 a            29 a    

Mean values in columns followed by different letters are significantly different, LSD, P=0.1.

Table 2.

                                                            GPA/3 plants    Damaged Leaves

Treatment                      Rate /acre     17 Jul               20 Jul              

Baythroid 2E                2.8 fl oz           0.2   e            6.0   ef

fenpropathrin                0.3 lb (AI)        9.4   cde       6.4  def

buprofezin                    0.38 lb (AI)      29 abcd        9.8 a

Proclaim                       4.8 oz                61 abc        8.2 abcd

methoxyfenozide          0.2 lb (AI)         302 a            8.8 abc

Knack                          10 fl oz              3.0    e          10  a

Warrior T                     3.8 fl oz             0.0    e          5.0    f

Spintor/Tracer              4 fl oz                44  bcde     9.4 ab

Spintor/Tracer              6 fl oz               111 abcd     7.4  bcde

DE-225 5.9% F          3.8 fl oz             3.4   de        6.8   cdef

Untreated                     --                     73 ab              10  a               

Mean values in columns followed by different letters are significantly different, LSD, P=0.1.

Cabbage looper (CL); Trichoplusia ni (Hubner)         

            COMPARISON OF INSECTICIDES FOR CONTROLLING LARVAE, 1998:  Collard seed was planted in Sep at the AREC, Lane, OK.  The experimental design was a RCB with 5 replicates and 10 treatments. Plots were 2 rows wide (72 inches) and 20 ft long with  20 ft alleys cut between plots.  Plots were treated with insecticides using  a tractor-mounted hydraulic sprayer with nozzles mounted on vertical extensions and a broadcast application  of 72 inches from 6 hollow-cone nozzles applying  37 gal/acre  at 40 psi.  Plots were treated on 9, 16, and 23 Oct.  Plots were surveyed  to determine insect abundance on 12, 15, 22, and 26 Oct by examining 5 plants per plot and recording CL, armyworm and diamondback moth larvae.  Insect damage to plants was evaluated on 26 Oct by rating damage on a scale of 0 (no damage) to 3 (all leaves with feeding damage).  Data were analysed using ANOV and a means separation test based on average number of larvae per 5 plants with data averaged across survey dates and plant damage by plot. 

            CL were moderately abundant with populations exceeding recommended threshold levels in the untreated plots on each survey date.  Diamondback moth and armyworm larvae were present in low numbers throughout the plots on all dates and were included within survey counts as total lepidoptera larvae along with CL.  Each treatment with the exception of ABG6475 significantly reduced larval numbers in comparison to numbers in the untreated plots.  Each insecticide significantly reduced damage to plants in comparison to untreated plots.

Means in the same column followed by the same letter are not significantly different, LSD, P=0.1.

COLLARD:  Brassica oleracia L.  ‘Champion’

                        Diamondback moth (DBM);  Plutella xylostella L.                            

Cabbage lopper (CL); Trichoplusia ni (Hubner).                    

            COMPARISON OF INSECTICIDES TO CONTROL LARVAE, 1999:  Collard seed was planted in Apr at the AREC, Lane, OK.  The experimental design was a RCB with 5 replicates and 9 treatments. Plots were 2 rows wide (72 inches) and 20 ft long with  20 ft alleys between plots.  Plots were treated with insecticides using  a tractor-mounted hydraulic sprayer with nozzles mounted on vertical extensions and a broadcast application  of 72 inches from 6 hollow-cone nozzles applying  37 gal/acre at 40 psi.  Plots were treated on 19 and 26 Jun.  Plots were surveyed  to determine insect abundance on 29 Jun by examining 3 plants per plot and recording insects present.  Data were analysed using ANOV and a means separation test based on the number of insects per 3 plants on average across survey dates.

            Lepidoptera larvae were moderately abundant.  Each insecticide treatment with the exception of tebufenozide and emmamectin benzoate resulted in significant reductions of DBM larvae in plots in comparison to the untreated plots.  Application of Dipel, fipronil, spinosad and lambda cyhalothrin  resulted in significant reductions of CL larvae in plots in comparison to untreated plots.

Means in a column with the same letter are not significantly different (P=0.05, LSD).

COLLARD:  Brassica oleracia L.,  ‘Champion’         

  Cabbage lopper (CL); Trichoplusia ni (Hübner)        

            CONTROL OF INSECTS ON COLLARDS, 1998: Collard seed was planted on 6 Sep at the AREC, Lane, OK.  The experimental design was a RCB with 5 replicates and 6 treatments. Plots were 2 rows wide (72 inches) and 20 ft long with 20 ft alleys cut between plots.  Plots were treated with insecticides using a tractor-mounted hydraulic sprayer with drops, with a broadcast application of 72 inches from 6 hollow cone nozzles applying 37 GPA at 40 psi.  With the exception of Warrior T, each insecticide was mixed with a spreader, Thoroughbred, at a rate of 12 oz/100 gal.  Plots were treated on 13, 19, and 26 Oct.  Plots were surveyed to determine insect abundance on 16, 23, and 29 Oct and 2 Nov by examining 5 plants per plot and recording insects present.   Data were analysed using ANOV and a means separation test.

            CL were moderately abundant.  Each insecticide treatment significantly reduced abundance of CL relative to untreated plots.  However, there was no evidence of a difference among insecticide treatments.

Means in the same column followed by the same letter are not significantly different, LSD, P=0.1.

COLLARD:  Brassica oleracea L.  ‘Champion’                                Turnip aphid (TA), Lipaphis erysimi (Kaltenbach)                        Green peach aphid (GPA), Myzus persicae (Sulzer)       

            ACTIVITY OF ‘ORGANIC’ INSECTICIDES, 1998: Collard seed was planted on 1 Oct 1997 at the AREC, Lane, OK.  The experimental design was a RCB with 4 replicates and 4 treatments. Plots were 2 rows wide (72 inches) and 20 ft long with 20 ft alleys cut between plots.  Plots were treated with insecticides using a tractor mounted hydraulic sprayer with nozzles mounted on vertical extensions and a broadcast application of 72 inches from 6 hollow-cone nozzles applying 37 gal/acre at 40 psi.  Plots were treated on 7 and 14 Apr 1998.  Plots were surveyed to determine insect abundance on 9 and 16 Apr by examining 3 plants per plot and recording insects present.  Data were transformed to log10 values and analysed using ANOV and a means separation test with mean numbers averaged across survey dates as a mean number per three plants.  Non-transformed means are reported in the table.

            Aphids were moderately abundant.  M-Pede and Capsyn treatments each significantly reduced TA abundance when used alone in comparison to the untreated plots.  A mixture of Capsyn and M-Pede did not significantly reduce TA abundance in comparison to untreated plots.  No treatments resulted in significantly reduced abundance of GPA in comparison to the untreated plots.

Means in a column followed by the same letter are not significantly different, LSD, P=0.1.

COLLARDS:  Brassica oleracea L. ‘ Champion’

            Diamondback moth (DBM);  Plutella xylostella (L.)

            Cabbage looper (CL);  Trichoplusia ni (Hubner)

CONTROL OF LEPIDOPTEROUS LARVAE ON COLLARDS IN OKLAHOMA, 1997:  Collard seed was planted in Mar at the AREC, Lane, OK.  The experimental design was a RCB with 4 replicates and 9 treatments.  Plots were 2 rows wide (72 inches) and 20 ft long with 20 ft alleys cut between plots.  Plots were treated with insecticides using a CO₂ powered backpack sprayer with a broadcast application of 72 inches from 4 hollow cone nozzles applying 33 gal / A at 40 psi.   Plots were treated on 4, 8 and 14 Jul.   Plots were surveyed to determine larval abundance on 7, 11 and 17 Jul by examining 3 plants per plot and recording all larvae present.

           DBM and CL larvae were abundant throughout the test period with numbers greatly exceeding recommended thresholds for applications.  Applications of permethrin, chlorpyriphos, and Confirm + Dipel 2X resulted in significant reductions in numbers of DBM in comparison to untreated plots.  Applications of all materials except methomyl and chlorpyriphos resulted in significant reductions in numbers of CL.  Permethrin provided the best control across both species relative to other materials under trial.

_____________________________________________________________________

                                 Rate

Treatment                         lb AI/acre             DBM                        CL           

Confirm                        0.12                        9 ab                        11     de

Confirm                        0.09                        9 ab                        11     de

Confirm                        0.06                        9 ab                        19   bcd

Confirm + Dipel 2X      0.06 + 1 lb               4   cd                        9    c

methomyl                      0.9                          6 abcd                     20 abc

chlorpyriphos                1.0                          5   bcd                     25 ab

endosulfan                    1.0                           7 abc                      14   cde

permethrin                    0.1                           2       d                   11      e

untreated                        -                            10 a                        28 a                       

Mean numbers per 3 plants and averaged across 3 survey dates (date X treatment interaction not significant, P = 0.05).

Mean numbers in a column followed by the same letter are not significantly different, LSD, P = 0.1.