California garlic production moved over the hill from Gilroy, Calif., the self-proclaimed “Garlic Capital of the World” to the San Joaquin Valley, to get away from a bad neighbor.
Unfortunately, the bad neighbor also moved over the Coastal Range that separates the central valley from coastal valleys.
The bad neighbor is white rot disease, one of the key reasons there are fewer than 500 acres of garlic in the Salinas/Santa Clara valleys, according to Robert Ehn, technical manager for the California Garlic and Onion Research Advisory Board.
The move did not get away from the problem, says Ehn. It's only temporarily sidestepped it and the white rot shuffle is coming home to roost.
“We have practiced avoidance by identifying white rot fields and then never planting an allium crop in that field again,” Ehn says. “However, we are beginning to run out of prime allium land on the West Side.”
It's not just disease, however, that's smacking the domestic garlic industry on the head. “Disease is not the driver in terms of reduction in garlic acreage,” Ehn says. “It is also foreign competition with countries like China selling both fresh and processed garlic at a cost significantly below our production costs.”
The good news for California's garlic growers is that quality still counts. “Chinese imports have had a huge impact on the industry, but their quality is nothing compared to what we can produce here,” says Kevin Lehar, crops manager with Woolf Enterprises in Huron, Calif. “However, we need to solve the white rot disease problem so that we can grow garlic consistently on the same ground rather than moving from field to field and just avoiding the problem.”
One of the most promising developments in managing white rot in allium crops is a derivative of garlic sprayed on soil that actually tricks the disease into blowing up when there is nothing to fuel the fire. Diallele disulfide (DADS) — a biostimulant — mimics the presence of a host plant, thereby stimulating germination of the dormant white rot sclerotia.
When applied to a field with no actual white rot host present, sclerotia germinate, quickly cycle, die, and the remaining source of infection is greatly diminished.
DADS has been researched extensively by the University of California (UC). Mike Davis, UC plant pathologist, has been working with the compound since 1999. With a grant from the California Department of Pesticide Regulation (CDPR) he began testing the product at a variety of locations, including the UC's Intermountain Research and Extension Center in Modoc County, in northern Nevada, and at several other California locations. Other UC researchers involved in the study include farm advisors Joe Nunez, Kern County, Richard Smith, Monterey County, Thomas Turini, Fresno County, Shannon Mueller, Fresno County and Harry Carlson, Modoc County. Another grant from CDPR will enable an additional two-year study to begin this year.
“Research trials will start this fall in Fresno and Modoc counties,” Davis says. “They will include other materials not labeled for this exact use. Maxim and Folicur are the fungicides with the most promise.”
While conventional fungicides are also being evaluated, it might be the unconventional approach of a compound such as DADS that holds the most promise to solving the white rot dilemma. However, an unconventional approach will most certainly require more forethought from growers who are accustomed to a “quick fix”.
“Because the use of DADS requires applications at least a season in advance of planting an allium crop, our major emphasis is on developing application strategies and timings that fit current grower practices,” Ehn says. “The difficulty with using DADS is that we have to create a new paradigm. Processors typically contract with growers in the early fall to plant onions or garlic for the 2008 harvest. To use DADS effectively, processors and growers must commit this fall to using a treatment for a crop planted in the fall of 2008 for a 2009 harvest.
“That type of planning is difficult for growers and processors as the marketplace drives the demand for them to plant and harvest what their dehydrated products sales group forecasts in potential sales.”
Even so, Ehn believes DADS can be a valuable tool for growers in the garlic industry. “I think growers who own their own land will step up and treat some of their ground,” he says. “Growers who lease land — especially those in the Tulelake area who lease government ground — will be less likely to invest $200 per acre for a treatment.”
It largely boils down to how important garlic is in the rotational and financial mix for individual growers. “Garlic is an integral crop rotation in our operation,” Lehar says. “We're farming cotton, tomatoes and other row crops that are well served by rotating with garlic.”
It's not just a matter of domestic ag industry health. Recent U.S. news reports warn of numerous lead contaminated foods, toys and other products originating from China due to poor protocol and haphazard environmental standards. It stands to reason consumers might eventually take note and choose quality over price. In the meantime, U.S. growers have to figure out how to remain viable from a production standpoint. DADS may offer an avenue toward that goal.
“We have a high level of confidence that the biostimulant can provide control of the white rot organism equal to methyl bromide, Ehn says. “We routinely see 90 percent plus-control of the organism. However, 90 percent does not provide economic control without a conventional fungicide used at planting. This tool can also be used to prevent spreading the disease from known infected fields planted to cotton or tomatoes or fall lettuce, thereby preventing spread of the sclerotia to fields not previously infected.”
At this point there has been about 13,000 acres on the West Side identified as contaminated with white rot. While seemingly a “death sentence” for allium crops such as garlic, mapping in combination with DADS and fungicides could be a welcome breath of life for the industry.
“One of our objectives is to do a better job of mapping infected fields,” Ehn says. “We have GPS mapped fields where infection occurred, but we should be able to map specific areas where the infection is identified. That detail would allow us to specifically treat an infected area, plus maybe an additional 20 percent of the land around the infection. Precise identification would cut the cost per acre down to a reasonable number that growers could afford without having to try to work an agreement with the processor.”
There are numerous reasons why California garlic growers are reluctant to abandon ship. The obvious ones are quite persuasive.
“Garlic pumps a significant amount of money into California agriculture,” Lehar says. “The crop is largely contracted, thus it helps with budgeting and financial planning. It would be a sad state of affairs for a number of reasons if all of our garlic industry goes to China.”
The possibility is more than just a glimmer on the horizon. “China is very capable of fixing their problems and producing quality products, “Ehn says. “I just hope we stay ahead of them for a while.”
In the meantime, growers are taking a proactive, rather than reactive, stance. “California's garlic and onion industry (growers and handlers/processors) consider this issue important enough to form a research board through a marketing order,” Lehar says. “We assess ourselves in order to generate funds to address white rot and other threats to our industry.”
After all, survival in the “real world” — just like prime time T.V. — is not for those who sit back and let the competition get a leg up on the latest challenge.