In contrast, tebuthiuron comes in pea-sized solid pellets, which can be dropped from higher altitudes even in rainy or windy weather. This makes tebuthiuron applications much safer for pilots. The solid pellets are expected to hit target fields with better accuracy, increasing the effectiveness of applications. Pellets break down and disperse more slowly than liquid herbicides, making the application more likely to kill plants. At the same time, tebuthiuron, which is sold in the United States under the brand name Spike, is a highly toxic, extremely persistent, broad-spectrum herbicide.
Labels warn that even slight exposure to roots can kill trees.
Persistence means that the chemical compound breaks down slowly, so that the herbicide can remain potent for 15 months. In a moist environment, such as in the rain forests of southern Colombia, water can quickly carry persistent herbicides through the environment. Broad-spectrum herbicides are lethal to a wide variety of vegetation. Environmentalists and members of the Colombian government worry that the persistence of the herbicide will make fields useless for subsistence agriculture after the coca plants have been killed. The region's peasants rely on subsistence farming in the forest for survival.