Gabriel Rennberger speaking to Clemson Extension about his research.

Gabriel Rennberger, a plant and environmental sciences graduate student at Clemson University, spoke at the International Congress on Plant Protection in Vegetables in Guadalajara, Mexico, Aug. 16-17.

Over 100 people attended the International Congress on Plant Protection in Vegetables, organized by Intagri, a Mexican company that focuses on education about agricultural topics. Rennberger, one of 10 speakers at the conference, gave his talk entirely in Spanish on the topic of his research at Clemson: foliar diseases within melons and the management options for those diseases.

“My Ph.D. research was about fungal diseases that affect the foliage of cucurbits like cucumbers and watermelons, especially a disease called gummy stem blight on watermelons,” said Rennberger. “The disease is caused by the fungus Stagonosporopsis citrulli and two other fungi in the same genus. I have also worked on different projects but a major one was a survey of foliar diseases of watermelon in South Carolina for which I sampled 6,000 watermelon leaves from sixty fields of the course of four seasons. That research is used to provide growers with better management recommendations as it estimated the prevalence of watermelon diseases present on commercial farms in South Carolina and also correlated some cultural and environmental factors with the occurrence of those diseases.”

Anthony Keinath, a professor of plant pathology and research and Extension vegetable pathologist at Clemson University and Rennberger’s advisor, learned through their research that gummy stem blight reduces watermelon yields by 15 percent, equaling about a $6 million loss for South Carolina farmers.

Rennberger’s research work with Keinath and frequently practicing public speaking as a Ph.D. student – with talks ranging from field days at Clemson research stations to talks at scientific conferences and other extension related meetings – made Rennberger the perfect candidate to speak at conference about protecting our plants.

“Anthony Keinath always made sure I gave several talks each semester,” said Rennberger. “Public speaking comes natural only to very few people and I am not among them. The only thing that helps one to improve this skill is to keep doing it. I found that with each successful talk I gave I got slightly more comfortable with it so that I not as nervous about it anymore. Therefore, the frequent practice during my Ph.D. was a good preparation for the talk in Guadalajara.”

Keinath admires Rennberger’s accomplishments through his research and public speaking.

“It is rare for a graduate student to be invited to give a talk at an international conference,” said Keinath. “I think it is even more impressive that Gabriel gave the talk in Spanish, since he is fluent in German, English and Spanish. He is the most productive graduate student that I have advised to date. His work is top-notch and thorough. He is organized and leaves no stone unturned in his projects.”

Intagri, the company that organized the conference, paid for all of Rennberger’s travel expenses.

“They organized everything very well, and I am very grateful for their invitation,” said Rennberger.