Yellow dragon disease threatens citrus crops worldwide. The bacteria that causes the disease clogs the flow of nutrients through the tree, turning the leaves yellow while the fruit remains green, lopsided, bitter and unusable. Courtesy: www.abc.net.au, Ian Lovett, New York Times

Yellow dragon disease threatens citrus crops worldwide. The bacteria that causes the disease clogs the flow of nutrients through the tree, turning the leaves yellow while the fruit remains green, lopsided, bitter and unusable. Courtesy: www.abc.net.au, Ian Lovett, New York Times

Notimex reports that a group of researchers at the Interdisciplinary Center of Marine Sciences (CICIMAR) of the National Polytechnic Institute of Mexico are researching the applications of algae extracts to combat the “yellow dragon” disease that attacks citrus crops.

Scientists conducted an analysis of algae extracts that have bioactive materials that can be potentially toxic for the Diaphorina citri, (also known as the Asian psyllid), the vector that carries the huanglongbing (HLB), or yellow dragon disease.

Ana Laura Gonzalez Castro, a doctoral student in Marine Science at the CICIMAR and author of the research, said that, even though they have identified algae extracts that have an insecticidal action, they still haven’t determined which compound is toxic for the Asian psyllid.

“We conducted tests with three extracts of brown, red, and green algae of the Sargassum genus, which is very abundant in the area of San Juan de la Costa, and the Laurencia algae, which is a red alga.”

“We also worked with the Caulerpa genus, a green algae. But we still haven’t determined the compound,” she said.

Mauricio Muñoz Ochoa, a professor and researcher at the CICIMAR, who has been a consultant on the study, said that the identified compounds had been subjected to laboratory tests, placed in containers of microbiological use, and placed in contact with the Diaphorina citri.

Afterwards, they analyzed the data regarding the required effects, mainly the number of insects that died during 24 hours of exposure.

Their results indicated that the extracts can be used preventively as a pesticide against the insect carrier of the bacterium that causes the HLB.