9781422282922

14

S T E M I N C U R R E N T E V E N T S

Battling Disease No matter how many times farmers test their soil, it may not be enough to keep away infectious plant diseases. Citrus greening disease is one example: caused by a strain of bacteria spread by tiny insects, it destroys citrus trees by turning their fruit green, hard, and inedible, and by damaging their roots. Infected trees die within a few years. It can have a devastating impact on the citrus industry, both in America and abroad. In Florida, where oranges and other citrus are a $10.7 billion industry, the threat of citrus greening disease has been especially dangerous. Since 2007, the state has lost some 100,000 citrus trees and $3.6 billion in revenue due to the

Energy From Oats

Next time you eat oatmeal, you might be helping to reduce overall carbon-dioxide emissions. When we burn coal alone, there is a high amount of these emissions. Environmental researchers in Iowa have found that burning oat hulls, the outer casings of oat seeds, along with coal cuts the amount of emis- sions by 40 percent. It also reduces the amount of hazardous particles and heavy metals such as copper and zinc that coal releases into the air. Oat hulls are an example of biomass, which is any plant-based energy source. Other examples of biomass include algae, cornstalks, and one of mankind’s oldest forms of energy, firewood.

disease. Using the science of genetic engineering, where genes fromone organismare used tomodify another, researchers from the University of Florida recently developed a new citrus tree that resists greening.The researchers used a gene isolated from a tree from the mustard family. This gene helps the new trees defend themselves against bacteria. More work has to be done before the trees are available to farmers, such as transferring the gene to the many varieties of citrus grown in Florida. But

Made with FlippingBook - Online catalogs