A Management Guide for Invasive Plants in Southern Forests James ...

27Soil SpotsSpots of soil-active herbicides (mainly Velpar L and Hyvar X-L) are applied as spacedmetered amounts around target woody stems or in a grid pattern for treating manystems in an area. Spots are usually applied with a utility spray bottle (herbicide-resistantseals preferred) or with operator-timed pulses from a hand sprayer or backpack sprayerequipped with a straight-stream nozzle. This method requires attention to preparingexact amounts and making prescribed spacings in strict accordance with specificationson herbicide labels or label supplements. It is effective only on specific nonnative plantspecies and usually only in spring and early summer. Any desirable plant with roots inthe spot area can be killed or injured, making this appropriate only for dense infestationsof a single invasive species such as tallowtree [Triadica sebifera (L.) Small], bamboos(Phyllostachys spp. and Bambusa spp.), and Brazilian peppertree (Schinus terebinthifoliuRaddi). Loblolly pine (Pinus taeda L.) is tolerant to Velpar L, and, thus, can be releasedfrom susceptible invasive shrubs and trees.Basal soil spots.Under Development: Pneumatic Applicatorfor Herbicide Ballistic TechnologyNew equipment options under development for invasive plantmanagement include paintball guns with herbicide-filled ammunitionfor basal applications. Researchers at the University of Hawaiiare studying how paintball guns might help selectively control avariety of species in hard-to-reach areas. From the ground orhelicopter, sharpshooters can apply herbicides in a very selectivemanner with this tool.Broadcast Herbicide ApplicationsMany infestations of nonnative plants are too extensive or denseto permit selective herbicide applications, and instead requirebroadcast methods. Herbicides with appropriate selectivity canbe used to minimize damage when native species are tolerant.Paintball gun basalapplication ofherbicides.Steven T. ManningBasal hit withherbicide-filledpaintball.Broadcast applications can be discontinued in pockets of nontarget native plants, where selective methods are moreappropriate. In special plant habitats, small desirable plants can be protected by plastic covers during broadcasttreatment. Broadcast sprays of herbicides without soil activity can be applied to evergreen or early greening invasiveswhen native plants are dormant. Many equipment types are available for mounting broadcast application systemssuitable for the situation.Utility Skid and Trailer-Mounted SprayersComplete spray systems are available mounted on utility skids for hauling in truckbeds and as trailers for towing behind many types of equipment. Sprayers for treatinginvasives often have a tank with 100- to 250-gallon capacity and require 100- to200-foot hose reels attached to a handgun. A variety of handguns and nozzles allowapplicators to adjust spray volume, distance, and pattern. Sprayer pumps are usuallypowered by 2-stroke gasoline engines that require availability of adequate fuel andoil onsite. Truck- and trailer-mounted sprayers are parked at a convenient location,from where the applicator walks with a sprayer handgun into the infestation. The chiefbenefit of mounted sprayers is their capacity for holding and applying high volumesof herbicide-water mixtures. But their benefit is checked by such limitations as accessibilityto the infestation, hose length and weight, and provisioning of water in the field.Of mounted sprayers, the skid steer-mounted sprayer is best for getting into difficultterrain and stands.Steven T. ManningMachine mountable sprayer.