Herbaceous weed control (HWC) is an herbicide application that is sprayed over the top of newly planted seedlings. This program is designed to control the most competitive vegetation to newly planted pines, primarily grasses and broadleaf weeds. These groups of vegetation compete with your seedlings during the first two years after planting for sunlight, moisture, and nutrients. Controlling grasses and broadleaf weeds will improve seedling survival and maximize pine growth.
The most effective way to establish a new pine plantation is with herbicide site preparation. Early site preparation treatments in July or August are typically followed the next year with an early spring (March or April) herbaceous weed control treatment. This approach has been shown to maximize pine growth in the Upper Coastal Plain.
When site preparation occurs later in the season, or in the Piedmont, herbaceous weed control may be delayed or eliminated depending on competition on the site. In most situations, an herbaceous weed control treatment in the second year after planting will positively impact pine growth. The number of treatments will vary based on site, competition, species planted, and previous management practices. Research has shown that when herbaceous weed cover is greater than 20%, another HWC treatment will be beneficial.
Application choices
There are two application techniques for herbaceous weed control, banding and broadcast. Banding applications are usually performed by hand crews with backpack sprayers treating a 4 to 5 ft. band down the row of seedlings. Broadcast applications typically utilize a helicopter to treat the entire site. The advantage of this technique is it eliminates any potential seed source from the untreated areas left after banding.
Years of success
There is a long history of successful herbaceous weed control programs. For loblolly pine plantings Arsenal AC and Oust XP are commonly utilized. For slash and longleaf pine, Velpar DF is a common product. The products utilized will depend on the site, species planted and competitive vegetation present. In certain situations, Oust Extra or Escort XP may be required. Esplanade F can be utilized over the top of all southern pine species. Note that a minimum of 0.25 inches of rainfall must occur within several weeks after application to activate this herbicide.
You may change the products for herbaceous weed control from those utilized during site preparation and between the first and second HWC treatments. This lessens stress on the pine seedlings and improves the spectrum of vegetation controlled.
Reaching new heights
To help your pines get a jump on the competition, contact your local Azelis A&ES representative. They will provide expert advice on the most effective products, application techniques and timing for your sites.
Azelis A&ES has experienced representatives that can help you make the right decision for your land management objectives. We are ready to provide you with a safe and effective solution.