A bamboo is an ornamental, large perennial grass that can grow up to 70 feet tall. It uses rhizomes to store energy, which can be invasive and difficult to contain. Exhausting and killing the entire rhizome network are the best ways to control bamboos, making management of bamboos intensive and difficult. Fortunately, there are herbicides that can help in this effort.
Amitrole is a very effective herbicide in controlling bamboos; however, it is also hazardous. Some professionals are against using amitrole because it is a soil sterilant, which has a high solubility and slow degradation, posing risk to other plants nearby. Furthermore, it can also pose risk to both ground and surface water quality. It comes in solid, dust or solutions forms.
Cut down the wood and spray amitrole on re-growth when it reaches half a foot high and in active growth. Repeat the application in case the new growth persists. It may take up to four weeks to notice the effects. Amitrole inhibits carotinoid synthesis and chrlolophyll formation, which are important in regrowth of bamboos.
Pregnant women should not handle amitrole because it may cause birth defects. Wear protective equipment to avoid skin and eye contact, as well as, vapor inhalation. Inhaling vapors may cause dizziness and nausea. This herbicide can also cause skin irritation and may be poisonous when ingested. Prevent run off into drains and waterways. Use absorbent (soil, sand or other inert material) to remove excess. Collect and seal in properly labeled containers.
Glyphosate is a type of chemical used for concentrated herbicide stump paint to kill woody weeds such as bamboos. One main advantage of glyphosate over other types of herbicides is that it has no soil activity and will only affect or target plants that are in direct contact with the spray solution. Furthermore, glyphosate is water soluble, odorless and nonvolatile. It has low toxicity compared to amitrole.
The best way to apply glyphosate is by spraying on the foliage of the bamboo. Be careful not to allow spray to drift to the foliage of other plants nearby. It is a broad-spectrum herbicide, which means it cannot distinguish the good plants from the bad; therefore, may cause injury and harm to other plants it touches. Upon application, glyphosate crosses the plant surface and moves throughout the plant.
The chemical accumulates in actively-growing parts of the plant, disrupting the pathway necessary for the plant’s survival. Once exposed to glyphosate, the bamboo will display stunted growth, green color loss and wrinkled leaves. The bamboo will die several weeks after. Spraying any regrowth from the root system once it reaches 18 inches high will prevent it from growing and spreading.
Effects of glyphosate on human health and the environment depend on how much glyphosate are present, the length and frequency of exposure, the health of a person and/or certain environmental factors.
Imazapyr is a more effective herbicide than glyphosate; however, it is also more harmful. It is broad-spectrum and has a huge amount of foliar and soil activity, which becomes a great concern because it can kill hardwood trees, shrubs and all nearby plants.
Imazapyr-containing herbicides are irritating to both eyes and skin. It is corrosive to the eyes and can cause irreversible damage. This herbicide can move readily in soil and can persist for over a year. It can contaminate the surface and ground water following aerial and ground forestry applications. According to the Northwest Coalition for Alternatives to Pesticides (pesticides.org), imazapyr may also cause cancer.
Once sprayed on roots or foliage, imazapyr kills plants by inhibiting the first enzyme used when plants synthesize branched chain amino acids.