Originally from Japan, kudzu is a vining plant first planted in the United States in the nineteenth century by southern farmers looking for a fast-growing plant that cattle and other livestock could graze. Kudzu hay has a high nutritional content compared to other types of forage. Unfortunately, the nutritional quality decreases as vine content increases relative to the leaf content. Unlike alfalfa hay, which grows like a grass, kudzu is hard to bale due to its vining growth and tendency to absorb rain. The climate of the Southeastern U. S. is perfect for growing kudzu. The vines grow as much as a foot a day during summer months, climbing trees, power poles, and anything else they contact. Under ideal conditions kudzu vines can grow 60 feet each year. Southerners joke that if you don’t close your windows at night, it’ll climb inside the house. In Japan, kudzu is kept in check by insects, but it has no natural enemies in the U. S.
While they help prevent erosion, the vines can also destroy valuable forests by climbing trees and preventing them from getting sunlight. This problem has led researchers to find methods for killing kudzu. After years of research, they found that one herbicide actually makes kudzu grow better while many have little effect. Even with the most effective herbicides, it takes many years to kill the plants.
Today, kudzu covers more than seven million acres of Georgia, Alabama, and South Carolina.
Which of the following can the reader infer from the passage above?