The relatively new science of biotechnology can also help in developing alternative controls for pests. It is also possible to alter predatory insects or disease organisms to make them better at damaging weed or insect pests. However, the effectiveness of some pathogens may be limited-they damage the target weed, but only to a limited extent when the environment is less than ideal. Biotechnology can sometimes be used to improve the weed damaging effects of these pathogens. One of the things that limits the effectiveness of pathogens is their ability to enter the host organism, which is protected by its waxy outer tissues.
Biotechnology can enhance the ability of existing pathogens to get past the weed's defenses.
Since these enzymes are controlled by genes, researchers are using biotechnology to modify the genes of pathogens to enhance their enzyme production. More and better enzymes would make the pathogens better able to infect and damage target weeds. Another problem is that some pathogens may affect a broad range of plant hosts, harming not only the target weed but also crops. Researchers are developing ways to alter pathogens so that their impact is limited to target plants. This can be done by genetic manipulations that reduce spore production in order to limit the spread of the disease.