Nearly 15,000 acres of Veracruz, on the West Coast of Mexico, are dedicated to the production of potatoes. During the past 30 years, the fields of the Cofre de Perote area were affected by the presence of the golden nematode (Globodera rostochiensis), reducing performance of the crop by more than 40 percent.
According to records of the Institute of Ecology (INECOL) in Mexico, there were 6,000 cysts per kilogram of soil of the nematode, when the recommended amount by the European Organization for the Protection of Plants to not affect the crop yield is of just 40 cysts; the only options for control of the pest growers have had are highly toxic chemicals, many of them severely restricted.
Faced with this problem, researchers from the Network of Biodiversity and Systematics at INECOL effectively located and tested a fungus capable of feeding from the nematode, acting as a biological pest control method. The use of chemicals ceased and agriculture in the region improved.
Because of its importance at a global level, the bionematicide was intellectually protected and has a patent pending for Europe, the United States and South America, explains Gloria Carrión Villarnovo, head of the scientific project.
Plant parasitic nematodes are microorganisms that feed on the nutrients absorbed by the roots of plants. In the case of potatoes, instead of producing eight or 10 tubers, an infected plant generates only four or five, and of a smaller size than usual.
“Mexico is considered the second center of origin of the potato, after Peru. When studying the case, we saw that in the mountainous area of Cofre de Perote wild tubers are present and that the region could have fungal antagonists for the golden nematode,” said Carrion Villarnovo. “After a scan we found some in 2005 that could be potential biological control agents.
“The process was accelerated because we saw that agrochemicals were handled carelessly, even by children, in addition to the fact that the compounds went into the groundwater through runoff or stayed in the tubers, making the damages greater.
From the laboratory phase we went to the countryside, where fungi were tested until we found one that worked and which reduced up to 90 percent of the golden nematode population in two years by combining biological control with other methods for an integrated management.”
According to Carrion Villarnovo, funding opportunities were sought and the National Council for Science and Technology (CONACYT ) through the Sectoral Innovation Fund supported the project. With these resources a patent was requested and a 15-liter bioreactor was acquired to reproduce the fungus used in the experiments. “We are on track to scale fermentation and produce it in mass amounts,” she said.
Carrion Villarnovo also mentioned that the science team at INECOL also works in changing habits and customs of farmers that favor the introduction and spread of agricultural pests and diseases, mainly in the region of the Cofre de Perote; this technique can also be implemented in the regions where potatoes are grown and the golden nematode is present.
The Biodiversity and Systematics Network is currently studying the major pest problems for field beans (Vicia faba), one of the crops used for rotation in the highlands of the state, using the same bionematicide and some other biocontrol agents.
“In Mexico we have the knowledge to deal with this kind of problem and to perform research focused on the generation of biological pesticides, which is a very important issue for agriculture due to the increasing restriction on the use of chemical pesticides,” said Carrion Villarnovo.
This article was provided by Investigación y Desarrollo, the scientific branch of Mexico’s Consulting Press and Communication Society.