UNIVERSITY PARK, Pa. — Microbial communities naturally living on the leaves and stems of tomato plants can be manipulated to suppress diseases that reduce productivity, according to Penn State researchers, offering hope that growers someday can apply these mixtures of bacteria and fungi to protect plants and improve harvests.
In a new study that involved a greenhouse full of four lines of young tomato plants representing different treatments and control groups, researchers repeatedly “passaged” or transferred microbes — initially gathered from leaves of healthy tomato plants in the field — from one plant to another, which were subsequently inoculated with the bacterial speck pathogen.
After multiple transfers or passages of the microbes, disease symptoms such as brown-to-black lesions on leaves began to wane and, by the ninth passage, declined by nearly half.
This discovery has implications beyond tomato and even vegetable plants, suggested Kevin Hockett, assistant professor of microbial ecology in the College of Agricultural Sciences, who is a co-author on the research paper. The goal, he said, is to develop a process that enables growers to employ microbial communities in the field.