But there are drawbacks, such as insects from Asia invading our orange groves and killing the trees by rapidly spreading bacteria from one to another. Called yellow dragon disease or citrus greening, it showed up first in India, China, and Indonesia.
Recently it was found in Brazil and now it has reached groves in Florida and California. I’m sure Texas oranges will not be spared.
The disease is the work of bacteria that hide in the salivary glands of a tiny winged insect called the psyllid. The bug injects the germ into the plants as it drinks sap from their leaves. The result is to gum up the circulatory system of the tree and eventually kill it.
Currently there is no known cure. We don’t have a pesticide that kills the bugs in large enough numbers to arrest the disease. The worst-case scenario is that in five years, there might be no orange trees left in this country.
However, scientists are pursuing several possible remedies. One is importing a wasp from Asia that preys on the psyllid. According to a plant pathologist at Texas A&M, the best long-term solution may be genetic modification of the orange trees to make them resistant to the disease. Research is on-going.
As I thought more about this problem, one of my writers brought up the case of the boll weevil. Thought to be native to Central America, it migrated into this country from Mexico around 1890 and had infested all U.S. cotton-growing areas by the 1920s. It devastated the industry and the people working in the South (including the family of the writer).
In that case extensive use of pesticides like DDT provided only temporary relief. Then in the 1970s scientists developed a sophisticatedBoll Weevil Eradication Program in the U.S. which allowed full-scale cultivation to resume in many regions.The introduction of a parasitic wasp was one strategy that worked. Strangely enough, the invasion of another pest, fire ants, speeded up the wiping out of boll weevils.
To mention one more example of scientists’ figuring out how to control a major pest that bedeviled agriculture, I remember when screwworms were a terrible and costly problem for cattle raisers. It was determined that sterilizing and releasing huge numbers of male flies could control the population, because the females mated only once. By the 1960s, a massive government program had virtually eliminated the screwworm flies in the U.S. It took longer in Mexico, but by 1990 the process had worked there as well.
These successful efforts to use scientific research to solve major agricultural problems of the past give me hope that I can look forward to enjoying a glass of orange juice in the future.
Jerry Lincecum is a retired English professor who now teaches classes for older adults who want to write their life stories. He welcomes your reminiscences on any subject: jlincecum@me.com
