Australian viticultural researchers have reported identifying genes in wine grape varieties that are highly resistant to powdery mildew and are working to transfer those genes to highly susceptible varieties.
If successful, according to University of California viticulture farm advisor for Madera County George Leavitt, that offers great promise for California grape growers to reduce pesticide use.
For example, Rubired is highly resistant to powdery mildew, but Carignane is not. If the genes that trigger powdery mildew resistance can be extracted from Rubired and inserted into new plantings of Carignane, it could mean growers would not have to treat as often for powdery mildew and sulfur may be all they would need, according to Leavitt.
However, it may be a race that may end in a dead heat or a dead issue.
If the Australians are successful, that would make the gene-inserted powdery mildew susceptible variety a genetically modified organism (GMO) and environmental radicals want to ban GMOs from California agriculture.
They have succeeded in banning GMOs in Mendocino County via a ballot initiative last spring. Humboldt County has a similar ballot initiative on an upcoming ballot.
“GMO technology offers the best opportunity grape growers have to reduce pesticide use,” Leavitt told growers and pest control advisers at a recent powdery mildew field day in Madera, Calif.
Leavitt said that movement is spreading from Mendocino and Humboldt counties to larger grape growing areas like Sonoma, Santa Barbara and San Luis Obispo.
“GMOs are going to be the next big fight for agriculture in the next five years,” said Leavitt. The battle will focus on row crops like cotton and corn, but it will spill over into permanent corps if efforts like those under way in Australia are successful.
Leavitt also believes the battle will eventually end up in court.
“I believe regulating GMOs is a federal responsibility, not county ordinances,” he said.