Kenneth Gravois

Farming, nursery and ranching operations are often threatened by newly introduced and unwanted insect pests or diseases. The origin of these invasive threats can come from within the U.S. or from outside the country. In a global economy, it is common for goods and services to cross borders. Many introductions of new plant or animal diseases are brought about simply by bringing in infected plants or items in small quantities without realizing the threat. An innocent looking plant could become a harmful weed or introduce a new disease.

The LSU AgCenter has breeding programs in many crops with the goal of improving yield as well as pest and disease resistance. An example is the sugarcane breeding program. In the late 1800s, new sugarcane varieties were collected from around the world and brought to the Louisiana Sugar Experiment Station in New Orleans for evaluation. New crop varieties are often brought in to improve yields and reinvigorate industries. Unknowingly, a new disease, sugarcane mosaic, was brought into the local Louisiana sugarcane industry. The new disease caused significant yield loss during the 1920s. However, there is a great benefit to obtaining new varieties either for local production or for use within the breeding program to make new crosses whose offspring may present greater value to the local industry.

New procedures were put into practice to introduce new varieties with less risk. Today, federal and state agencies have primary missions to protect the health and value of agriculture and local environments. At the federal level, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) is the first line of defense. There are federal laws governing the importation of sugarcane (plants, cuttings, leaves, etc.) into the U.S. New sugarcane varieties from overseas are brought into quarantine facilities in Maryland through a permitting process. The sugarcane plants are grown in isolation greenhouses and a battery of disease tests and inspections for insect pests are performed. Once cleared through the 18-month quarantine process, the new varieties are shipped to the research personnel who requested the new germplasm.

APHIS has an office in each state that cooperates with officials from the state agriculture departments. Procedures also govern the movement of sugarcane among the sugarcane growing states. It is common for sugarcane varieties to move among the breeding programs of Louisiana and Florida. To reduce the threat of an introduction of a new sugarcane disease, insect pest or harmful weed, quarantine procedures are in place to reduce the threat. Plants (or stalks) are first visually inspected for any disease. Next, laboratory disease tests are conducted by plant pathologists to determine the presence of any disease. Prior to being sent, sugarcane stalks are submerged in hot water to destroy those diseases or insect pests that are controlled by heat. When the varieties are received at the point of destination, each is germinated in isolation or quarantine greenhouses, observed for the presence of disease or insects, and again checked with laboratory detection methods. The process is rigorous but necessary to ensure safety.

These same principles apply to all farming, nursery and ranching operations. Before ordering a plant or animal online from another country or even another state, please check the quarantine laws by contacting the Louisiana Department of Agriculture and Forestry. The process may be tedious but necessary and vitally important to the agriculture economy.

Kenneth Gravois is the LSU AgCenter sugarcane specialist.

(This article appears in the winter 2022 issue of Louisiana Agriculture.)

Author Kenneth Gravois, LSU AgCenter sugarcane specialist, was the recipient of the LSU College of Agriculture 2021 Outstanding Alumni Award. Gravois is a member of the Louisiana Agriculture editorial board.