Multiflora Rose Control

Bulletin 857

Soil Applications

1. Dormant Spot Concentrate: This treatment method uses a hand-held spot applicator to apply a measured quantity of herbicide to the ground beneath plants within 6 to 8 inches of plant crowns. The quantity of herbicide applied depends on the estimated diameter of individual multiflora rose plants or plant clumps. This technique is particularly useful in killing scattered roses growing on steeper terrain and for follow-up retreatment applications. Spot applicators are sold for $50 or less through veterinary and farm supply houses. They generally can be set to deliver 4 or 8 milliliters per trigger squeeze.

   Figure 10

   The applicator carries the light pistol-type spot gun in one hand (Figure 10). The gun is attached by plastic tubing to a 1-gallon, hand-held container. As with basal dormant spraying, selection of a winter day with a light dusting of snow allows foot tracks to determine which bushes have been treated. Labels permit applications to frozen ground as long as snow or water does not prevent proper placement to the soil surface. On sloping ground, the herbicide should be placed upslope from the plant crown wherever possible. With larger plants, divide herbicide between two or more places near crowns to intercept more roots.

   Two herbicides are labeled for dormant spot concentrate applications: dicamba (Banvel) and metsulfuron methyl (Escort only, not Ally). Banvel is labeled for use in pastures. Both of these herbicides should be applied after soil temperatures drop below 40 degrees F and before multiflora plants initiate significant spring leafout. Application when soil temperatures are low is especially important with Banvel to inhibit breakdown by soil microorganisms before proper root uptake by rose plants. Reduced effectiveness of Escort when applied after leafout suggests breakdown in soil is also a concern with this herbicide. Banvel is applied undiluted, based on plant canopy diameter (see Table 5). Do not exceed 2 gallons of Banvel per acre with this technique.

   
   

   Table 5. Banvel spot concentrate application rates
   Plant canopy diameter	Banvel (4 DMA) needed
   	English or metric
   5 feet	1/4 oz = 7.4 ml
   10 feet	1 oz = 30 ml
   15 feet	2 1/2 oz = 74 ml

   Escort solution is prepared by mixing 1 ounce (29.6 gms) of Escort 60% DF with 0.3 ounce (10 milliliters) of nonionic surfactant in 1 gallon (3785 milliliters) of water. Agitate the container occasionally during application to keep herbicide in suspension. Apply this solution to the base of plants at the rate of 8 milliliters for each 2 feet of plant canopy diameter. Prepare fresh mixture daily because metsulfuron methyl gradually breaks down in water by hydrolysis.

   While acceptable results generally occur with application of these products to dormant rose, occasional instances of unsatisfactory control have occurred (see Table 6). Because root uptake is involved, lack of precipitation after application may occasionally inhibit movement into soil and reduce efficacy.

   
   

   Table 6. Multiflora rose control in Ohio winter field trials of dormant spot-applied herbicides
   Product	Number of trials	Mean BRR rating1	% of trials with complete plant kill
   Banvel	16	1.5	56%
   Escort	10	1.2	60%
   1. BRR (basal resprout rating) where: 1 = none, 2 = slight, 3 = moderate, and 4 = extensive basal regrowth 8 to 15 months after application.

2. Soil Treatment with Pellets: Spike 20P is presently the only herbicide pellet labeled for multiflora rose control. It is usually hand scattered at the rate of 1/4 ounce per 22 square feet of plant canopy area. The active ingredient, tebuthiuron, is an extremely active, total vegetation control herbicide. It kills multiflora rose and other woody plants, grasses, and weeds by root uptake. Initial defoliation often is followed by several cycles of leafout and subsequent defoliation. The presence of yellowish tissue in the tips of stem growth indicates that further leafout and defoliation cycles should occur. Spike will kill trees, bushes, forages, and other desirable plants if their roots extend into treated areas. Remember that feeder roots of desirable species may extend beyond the dripline of topgrowth. Also, the tebuthiuron in Spike 20P can readily leach downslope 10 feet or more if sudden heavy precipitation occurs before the herbicide has moved down into the soil profile. Spike 20P is more likely than the previously sold picloram pellets (Tordon 10K) to kill or severely damage nearby vegetation.

   Note that these two products provide similar results across many trials (Table 7). The degree of plant kill with Spike 20P is inferior to results with previously mentioned spot concentrate soil treatments. As shown in Figure 11, Spike 20P provides the most consistently effective control when applied during winter months.

   Table 7. Multiflora rose control in Ohio with Spike 20P and Tordon 10K pellets1
   Product	Number of trials	Mean BRR rating2	% of trials with complete plant kill
   Spike 20P	20	1.9	15%
   Tordon 10K	18	1.6	33%
   1. Data for both represent January through mid-September application dates.
   2. BRR (basal resprout rating) where: 1 = none, 2 = slight, 3 = moderate, and 4 = extensive basal regrowth 8 to 15 months after application.

   
   
   

   Figure 11

Back | Forward | Table of Contents