Enhancement of phenoxy effects by addition of Assist. Guggenmoos, S. 

Stem kill was previously reported in this trial where Assist oil concentrate was added to a commercial application of diphenoprop intended to control 2 metre regrowth of tall growing tree species on a power line right of way in the Judy Creek oilfield, Alberta. Application occurred between August 12 and 14, 1987 using a hose and gun from both aerial bucket and soft track machines. Assist, at 0.5% v/v, was added to a mix of 350 g 2,4-D plus 350 g 2,4-DP per 1000 L solution. Brush was sprayed to the point of run-off with an average volume of 1885 L/ha. Stem kill, sprouts and sprout length were evaluated for poplar species on October 25, 1989. These results are compared with the standard treatment of 350 g 2,4-D plus 350 g 2,4-DP per 1000 L solution sprayed to run-off. Data for the standard is derived from previous trials. 

Comparison of diphenoprop vs diphenoprop + Assist for brush control

                                                                                              MEAN STEM KILL        SPROUT FACTOR2
                                                                                                    Trembling     Balsam        Trembling    Balsam
TREATMENT                          a.i./1000 L                               aspen            poplar          aspen           poplar

2,4-D + 2,4-DP                           350g + 350g                              9 b1             4 a                   118 b1         20 a
2,4-D + 2,4-DP + Assist           350g + 350g + 0 .5%                9 b               9 b                   107 b           18 a

1Duncan's Multiple Range Test at 5% level

2number of sprouts X maximum sprout length

Stem kill for balsam poplar was significantly increased by the addition of Assist at 0.5%
v/v. No significant reduction in sprout formation and growth, as indicated by the sprout factor,
was observed. (TransAlta Utilities, Sherwood Park, Alberta)

Ecosync Home