(09/19/24) BATON ROUGE, La. — Taking the place of a 40-year veteran of the Louisiana sugarcane industry is no small task, so when LSU AgCenter plant pathologist Andre Gama replaced longtime researcher Jeff Hoy, he knew he had big shoes to fill. Due to his extensive travels, Gama’s own shoes were well worn, so he was up for the challenge.

Growing up in Piracicaba, São Paulo, Brazil, Gama knew from a young age that he was interested in studying biology but wasn’t sure what to focus on. In his home country, students are expected to decide a university major when they turn 18, so he needed to figure it out fast.

“My family has no farm background, but since I was interested in plants and food production, I chose an agriculture major,” he said. “When I took plant pathology in my third year at the university, I knew this is what I wanted to do.”

During his undergraduate studies at the University of São Paulo Luiz de Queiroz College of Agriculture, Gama researched the effects of brown and orange rusts of sugarcane on photosynthesis. A postdoctoral assistant he was working for recommended him to Richard Raid, a pathologist at the University of Florida, where he finished his degree researching pineapple rot of sugarcane in 2014.

“It’s called pineapple rot because the fungus produces ethyl acetate in the sugarcane plant, and the smell reminds you of pineapples,” he explained.

After his studies in the Sunshine State, Gama applied for his master’s degree in his previous lab in Brazil and was given the choice to work on grapevines or citrus.

He said the citrus project reeled him in because it involved developing an automated, online, decision-support system to aid growers in deciding the best time for fungicide applications based on weather forecasts and disease models.

The decision-support system targeted postbloom fruit drop of citrus, a fungal disease that causes fruit to fall off trees prematurely. This is especially problematic in the southwestern portion of the citrus belt in Brazil, which is the world’s No. 1 producer of orange juice.

“I thought it was cool that the growers could use the online system to guide their fungicide applications because before that, they were spraying four to six times in a season without knowing if the conditions were conducive for the disease,” he said.

Using mathematical models that correlate disease risk with weather variables like temperature and leaf wetness periods to guide sprays, Gama and his team were able to reduce fungicide applications by up to 75% per season with the same efficacy, thus reducing environmental impacts from fuels, fungicides and water usage and providing financial benefits for growers with a positive effect on yield.

“That project was enormously successful, and the growers are using the automated system to this day,” he said.

Gama then returned to Florida for his doctorate when the state was facing postbloom fruit drop in citrus. He said the University of Florida had a similar system for strawberries as Brazil had for citrus, so his professor collaborated with counterparts in Brazil to implement and design an automated system for orange production in Florida similar to the one that was so effective in Gama’s home country.

“We validated the system for oranges, and it worked very well. This disease doesn’t occur every season, but the growers were spraying every year out of a sense of caution,” Gama said. “There is now an app where producers get an alert on their phone when it’s the best time to spray.”

He said during the validation of the automated system in Florida, only one fungicide application was performed in four seasons. Before, growers were spraying two to three times every season for the disease.

Gama also helped develop a system for blueberries during his doctoral studies, testing different ways to estimate leaf wetness duration based on other weather variables that were commonly obtained in the field.

After graduating, he went through a five-month postdoctoral stint working on Pestalotia fruit rot and leaf spot of strawberries before moving into the private sector working on Huanglongbing, or citrus greening, a devastating disease that caused a steep decline in orange juice production in Florida. After a year and a half, he realized his true passion was teaching and putting his own research ideas to the test, so he made himself a promise.

“I told myself if a good academic job came up, I would apply for it,” he said. “And that’s when I saw the AgCenter position, giving me the opportunity to work with sugarcane again, which I hadn’t done since my undergrad days. I especially liked the job description, which was applied disease management, working directly with growers.”

Gama now gets to teach epidemiology, describing how diseases grow in the field, become more severe and how to test ways to mediate that effect. He also provides free diagnostic services for sugarcane growers in Louisiana, sponsored by the American Sugar Cane League. To optimize the diagnosis for local growers, he and his team are working on improving methods for detecting sugarcane pathogens, including the causal agents of ratoon stunting disease and sugarcane leaf scald.

“We’re excited because we’ve found ways to extract pathogen DNA from sugarcane samples way quicker than we could before without increasing costs while increasing the sensitivity of the assays,” he said. “This comes from what I learned in Florida and implemented in the strawberry disease diagnostic lab.”

When asked how working in Louisiana and at the AgCenter differs from his previous academic stops, he referenced the food and the people.

“The food is amazing!” he exclaimed. “And the growers are very curious and involved. The difference here is you have a sugarcane industry that is more composed of families rather than big corporations, which I really enjoy because I feel that we as researchers can make a bigger difference.”

Gama also singled out his predecessor Hoy, who he said was instrumental in teaching growers over the decades about the importance of using clean seed cane. He also praised AgCenter sugarcane breeders, who have led the way in breeding disease-resistant sugarcane varieties.

“The day before I started, Jeff had his retirement party and was nice enough to invite me,” he said. “Now I know why folks spoke so highly of him. I learned the tremendous impact he had on the industry and how great of a person he is.”

Over time, Gama hopes to make his own impact on the Louisiana sugarcane industry and wants producers to know he is always ready to help.

“I always like knowing what I’m doing is helping someone,” he said. “In all our research, the final goal is to help the growers.”

LSU AgCenter pathologist Andre Gama examines sugarcane for rust at the Sugar Research Station in St. Gabriel. Photo by V. Todd Miller/LSU AgCenter

LSU AgCenter pathologist Andre Gama speaks to producers about how to prevent the spread of diseases at the 2024 sugarcane field day in St. Gabriel. Photo by Olivia McClure/LSU AgCenter