APHID MANAGEMENT ON HEAD CABBAGE, 1997:

 

R. F. L. Mau and L. R. Gusukuma-Minuto
University of Hawaii
Dept. of Entomology
3050 Maile Way, Rm. 310
Honolulu, HI 96822
Phone: (808) 956-7063

 

CABBAGE: Brassica oleracea L. ‘Tastie’

Cabbage aphid (CA); Brevicoryne brassicae L.

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

 

The study was conducted at the substation of the Kula Research Station, Maui Agricultural Park. A randomized complete block design with six treatments and four replications (blocks) was used. Each treatment plot consisted of a single row of cabbage planted at 18 in. between plant spacing. Each row consisted of 45 plants for a total length of approximately 70 ft. Treatment plots were separated by a 48 in. spacing. Blocks were separated by a 60 in. spacing. Total field size was 0.15 acres. Admire was applied on 25 Jun, one week after transplanting seedlings into the field. A hand injector was used to place the insecticide in the root zone. The field was irrigated immediately following the Admire application. Foliar treatments were applied on 22 July at a rate of 100 GPA and 60 psi using a CO2 backpack sprayer. The spray wand was equipped with a single hollow cone TX-26 nozzle. Aphid counts were made at pre-treatment, 6, 13, and 20 DAT. In conducting the surveys, the same ten plants in each treatment plot were examined. Alatae and apterous counts were made for the pretreatment, 6 and 13 DAT surveys. Only the total number of aphids was recorded at the last survey. Aphid species determination was made by the Entomology Departments’ insect taxonomist.

Aphid alatae were observed on the plants during the first four weeks after transplanting. Initial infestations consisted of CA and GP. Treatments were made when aphid colonies exceeded 5 apterous aphids/plant. Acetamiprid and Provado foliar treatments effectively controlled the aphids with just one application. Effective control was maintained for about two weeks as shown by 6 and 13 DAT aphid counts. Aphid colonies increased rapidly in all acetaprimid treatments after the 13 DAT survey. At 20 DAT, aphid counts were very high in the UTC, moderate in the acetamiprid treatments and lowest in the Provado plots. The Admire treatment provided excellent aphid control for about 6 weeks.

 

                                                                                      Number of aphids/10 plants
                                                                __Pre-treatment (21 Jul)__         ___6 DAT (28 Jul)___
Treatment/formulation     Rate
amt/acre
    Alatae   Apterous     Alatae   Apterous
EXP90667A 70 WP     0.05 lb. (AI)     0.13+0.06ab   13.35+5.26b     0.05+0.03b   0.08+0.06c
EXP90667A 70 WP     0.075 lb. (AI)     0.28+0.09ab   12.85+3.38b     0.0b   0.98+0.75b
EXP90667A 70 WP     0.10 lb. (AI)     0.30+0.10ab   23.60+6.01a     0.0b   0.0b
Admire 2 F     12.0 oz.     0.03+0.03b   0.13+0.13b     0.30+0.13b   2.40+1.80b
Provado 1.6 F     2.8 oz.     0.18+0.07ab   24.20+5.79a     0.0b   0.03+0.03b
Untreated check     ---     0.40+0.11a   33.78+6.00a     2.02+0.37a   112.70+22.58a

Means in the same column followed by a different letter are significantly different (P<0.0001, SAS for Windows version 6.11). Data was transformed by square root (Y+0.5) prior to analysis. Untransformed means are presented.

 

 

                                                                                      Number of aphids/10 plants  
                                                                  __13 DAT (4 Aug)__               _20 DAT (11 Aug)_
Treatment/formulation     Rate
amt/acre
    Alatae   Apterous       Total aphids
EXP90667A 70 WP     0.05 lb. (AI)     0.18+0.09b   2.58+1.66b       199.63+60.08b
EXP90667A 70 WP     0.075 lb. (AI)     0.03+0.03b   0.20+0.20b       132.58+67.72bc
EXP90667A 70 WP     0.10 lb. (AI)     0.08+0.08b   4.55+3.01b       155.40+29.23b
Admire 2 F     12.0 oz.     0.50+0.35b   8.63+6.13b       79.53+38.97bc
Provado 1.6 F     2.8 oz.     0.0b   0.0b       0.20+0.14c
Untreated check     ---     4.75+1.44a   184.90+40.42a       1200.43+326.25a

Means in the same column followed by a different letter are significantly different (P<0.0001, SAS for Windows version 6.11). Data was transformed by square root (Y+0.5) prior to analysis. Untransformed means are presented.

 

 

Trade Composition\Common name     Formulation         name     Source
Admire     F         imidacloprid     Bayer
                       
EXP80667A     WP         acetamiprid     Rhone-Poulenc
                       
Provado     F         imidacloprid     Bayer