Participants in an organic farming conference at Fresno State University watched as bugs were vacuumed out of a research plot and heard about plans for the University of California to certify it first organic acreage at one of its field stations.
They also took home pointers on getting – and staying – certified for organic production, along with information on research at the campus, where organic production has grown from one acre in 2008 to 15 today.
Tom Turini, a Fresno County farm advisor with UC Cooperative Extension, emphasized that many of the same management systems in place for conventional agriculture apply to organic producers as they seek to address plant disease.
“The best approach is management before you see the disease or in its early stages,” said Turini, who frequently speaks to conventional growers of processing tomatoes and other vegetable crops on the Central Valley’s west side.
Turini said care should be taken to avoid movement of pathogens from infected fields, including getting mud off equipment. He also said growers need to control weeds, which can harbor pests and disease, and they should disc under or otherwise dispose of piles of culled fruits or vegetables.
Richard Molinar, another UC farm advisor in Fresno County, talked about food safety and said he expects the California Department of Food and Agriculture will seek to “get a handle” on who is selling produce directly to shoppers.
“Certified markets are well regulated,” he said. But roadside stands, swap meets and community supported agriculture operations are not, Molinar said.
He said CDFA is looking into registering those who sell direct to consumers and perhaps requiring a simple self-certification that includes a food safety pamphlet of about six pages.
“You should at least have a manual on good agricultural practices,” he said. “The industry (including buyers and distributors) is telling famers you need something in place.”
Molinar opened his talk by stating that the Kearney Ag Center in Parlier this year will, for the first time, have organic certification on ten acres. He said it will be the first UC field station with certified acreage, although there are organically certified acres at UC campuses that include Davis and Santa Cruz.
Here are some other highlights from the conference:
Ron Whitehurst, pest control advisor with Rincon-Vitova Insectaries in Ventura, demonstrated use of a vacuum to collect insects in a field. He said use of the device is helpful in monitoring for the proportion of insect pests compared to beneficials.
It also can be used to move beneficials from one field to another or to eliminate pests.
Rincon-Vitova sells the device as well as beneficial insects and other biocontrol products. Whitehurst said a cheaper approach to collecting the insects can be to use a leaf vacuum and nylon stocking.
Whitehurst said a strip of alfalfa can be planted to draw cucumber beetle pests away from vegetables, and then they can be vacuumed out of the alfalfa. He also gave advice on keeping spider mites at bay by using misting nozzles.
Jan Dietrick, general manager of Rincon-Vitova and Whitehurst’s wife, said she is concerned about the growing of Roundup Ready alfalfa, saying it compromises a crop that she said “is a reservoir of diverse insect ecology.”
Molinar said that lacewings purchased from Rincon-Vitova have proven very effective at controlling aphids on a research crop of mini watermelons.
“We haven’t had to spray in three or four years,” he said.
Whitehurst said “habitat seed mixes” can also be planted to attract beneficial insects.
Anil Shrestha, with the Department of Plant Sciences at California State University Fresno, talked about research he has been conducting on use of recycled paper mulch for weed control in the establishment of blackberries.
Shrestha said organic growers face special challenges because there are few registered chemicals for berry production.
He and others conducted research on the mulching in a transitioning organic plot at Fresno State. They found that weed biomass around the mulched plants was between 49 and 51 percent lower than around non-mulched plants.
Soil temperature was higher around the plants with no mulch, and soil moisture similar in the mulch and no-mulch plots. Lower soil temperatures in summer may have helped the plants and moisture was retained.
Shrestha said research with paper mulch in strawberries showed slower plant growth due to lowered temperature of the soil, but the mulch helped cut down on nutsedge growth.
He said controlling weeds organically has a range of costs – as much as $350 per acre with herbicides, about $150 for propane burning, steam in about that same range and cultivation at less than $100 an acre.
“Nothing beats iron,” he said, a reference to use of a French plow or a cultivator called the Bezzerides.
Sajeemas “Mint” Pasakdee, advisor to the student-run Fresno State organic farm, talked of research on various brassica plants as a forage crop for grazing lands during transition to organic cropping.
She and other researchers, including Shrestha, evaluated the use of the plants as a winter cover crop to augment growers’ incomes while building soil fertility and improving soil health.
Researchers looked at six varieties: Forage brassica, two varieties of forage turnips, tillage radish and canola. The idea was to test for reduction of soil-borne disease and weed population.
Pasakdee said researchers saw high weed pressure on a one-acre test plot only from broadleaf weeds, but not from grasses.
Earlier, Pasakdee talked of the importance of organic matter for the soil, saying “a good soil is a live soil” and adding that earthworms are “major decomposers of dead and decaying organic matter.”
Turini said some plant diseases can persist in the soil for decades, citing the example of white rot in garlic.
“There are 16,000 acres in the Central Valley that are infested,” he said.
In other instances, the disease cycle can be broken, but growers need to take into account what they are planting as part of a crop rotation.
For example, Turini said, the tomato spotted wilt virus has other hosts that include lettuce and radicchio “that can be a bridge.”
Some diseases, including a fusarium fungus “can sustain itself without causing diseases on the roots of other plants,” he said. “You may have to stay away from certain crops.”
Turini warned against using transplants from outside the region, notably from the low desert of California. He said that common pathogens can be introduced through seeds and transplants.
Timing of planting can reduce risks of certain diseases because of variability in soil temperatures, he added. And variety selection is important because some choices bring greater genetic resistance.
Cynthia Ortegon, regional service representative for California Certified Organic Farmers in the Central Valley, talked of steps to becoming certified.
She also talked of the need to use no prohibited substances under national organic farming rules three years prior to harvest and having distinct defined boundaries and buffer zones.
Ortegon said organic growers need to keep records of what they apply to their land and when they use materials “Keep all labels and receipts,” she said. Using the wrong materials can mean being put out of organic production for three years until recertification is done, she warned.