California leafy greens industry leader Mary Zischke took the podium at the 2012 Fall Desert Crops Workshop in El Centro, Calif., in November with disconcerting news about the U.S. consumer’s lackluster desire to eat vegetables.

Zischke, chief executive officer, California Leafy Greens Research Board, showed PowerPoint slides of USDA Economic Research Service data covering the last 30 years which showed that the per capita consumption of leafy greens had remained basically flat.

“The USDA data suggest that little consumption change has occurred despite the government’s efforts to convince the American public to eat a healthier diet,” says Zischke, chief executive officer of the California Leafy Greens Research Board (CLGRB) in Salinas, Calif. The USDA figures suggest the average consumer eats less than 8 ounces of leafy greens per week.

“This is a very disappointing figure,” Zischke says. “Leafy greens are one of the best nutritional stories in agriculture yet we don’t see much positive response from consumers.”

The data also show a large consumer consumption shift from iceberg lettuce to romaine lettuce.

Zischke says government data may not always be the most accurate information. She shared encouraging new data gathered by the California Leafy Greens Research Program (CLGRP), which the CLGRB oversees, which suggests the pendulum on U.S. leafy green consumption is swinging higher, including more portions of spinach and spring mix. “The spinach industry is on the rebound,” Zischke told the crowd.

The consumer just might be listening to the Obama administration’s ‘get healthy with vegetables’ message.

Zischke shared PowerPoint slides outlining the recent CLGRP data. From 2008-2009, California spinach production climbed from about 17 million cartons, equivalent to about 22 million cartons in 2011-2012; an increase of about 22 percent.

California is the nation’s largest spinach producer. About 80 percent of the crop is processed. The balance is sold fresh.

Spring mix, which includes various baby leaf lettuces, is also finding increased favor with consumers, the CLGRP says. California spring mix production has increased about 18 percent from about 13 million hundredweight in 2008-2009 to about 16 million hundredweight in 2011-2012.

Zischke discussed the latest in leafy green consumption plus the CLGRP’s crop research efforts during the Fall Desert Crops Workshop. The annual event was conducted by the University of California Cooperative Extension (UCCE) in Imperial County and was sponsored by Western Farm Press.

Refreshing news

These upticks in leafy green consumption are refreshing news for U.S. spinach growers who have looked for a resurgence for about six years.

An outbreak of the pathogenic 0157:H7 strain of Escherichia coli (E. coli) in California-grown spinach in 2006 hammered the domestic spinach industry. The tainted spinach was linked to five deaths and more than 270 illnesses.

The likely implicated source in the California E. coli-spinach case was an Angus cattle ranch leased for spinach production.

Consumers immediately lost confidence in the safety of spinach. Spinach sales sank like the iceberg-damaged Titanic. Estimated losses to the spinach production industry total in the hundreds of millions of dollars.

According to the Centers for Disease Control and Prevention, many E. coli strains are actually harmless and, in fact, are an important part of a healthy human intestinal tract.

Some strains are pathogenic, which when transmitted through contaminated water or food, or through contacts with animals or people, can cause severe diarrhea in humans.

California and Arizona growers produce about 95 percent of the U.S. vegetable crop. The main growing hub is along California’s Central Coast (including the Salinas Valley). Most winter vegetables are grown in the low desert regions of Southern California and Arizona.

The CLGRP organization dates back to an iceberg lettuce-only organization with a different moniker, founded in 1973 and formed under a State of California marketing order. The current program operates under the authority of the California Department of Food and Agriculture.

Spinach and spring mix were added to the CLGRP focus after the California E. coli-spinach event, along with the new program title.

Zischke’s affiliation with the CLGRP dates back more than 30 years. She conducted program research on lettuce downy mildew while a graduate student at UC Davis. She later served as a board member representing her previous employer Dole Fresh Vegetables.

Zischke has served as the board CEO for the last seven years.

The CLGRP is funded through mandatory assessments at the shipper level at the rate of $.00625 per carton.

The CLGRP’s top priority is leafy green crop research on plant breeding and plant pathology, pest management, food safety, and water quality. The research is conducted by scientists with the University of California, the USDA-ARS in Salinas, independent researchers, and other universities.

Over the last decade, the grower-funded program has spent about $850,000 annually on research. The largest funded area is plant breeding. “Multiple disease resistance is the top priority,” Zischke said.

Current breeding projects include developing plant resistance to fusarium wilt and verticillium wilt, downy mildew, and extending the shelf life of leafy greens destined for fresh market sales. 

Improved protocols

Current pest management research tackles the biology of downy mildew disease and root rot in spinach, lettuce viruses, the impact of rotational crops on soil-borne disease levels, and insecticide efficacy trials.

Food safety studies are often partnerships funded by the CLGRP and the Center for Produce Safety.

Water quality management research centers on denitrification chambers, crop nitrogen requirements, sediment reduction, and best management practices.

The CLGRP’s latest research accomplishments are available online at www.calgreens.org.

Researchers in CLGRP projects primarily tackle time consuming initial research and then provide potential solutions to seed companies for further development. Among the researchers include Trevor Suslow, UC Davis Extension research specialist.

Suslow discussed with the workshop crowd ongoing research on soil and water contamination that he and UCCE plant pathologist Steve Koike are conducting. The aim is to develop improved protocols for soil microbe management in vegetables which, in the end, could improve and impact food safety.

Field trials conducted by the duo suggest that bacterial pathogens can exist longer in the soil under higher soil moisture and milder temperature conditions, especially if associated with contaminated organic matter.

Once a field is disked after harvest, Suslow says both pathogenic E. coli and salmonella can live in the soil for more than 110 days. Research trials in 2011 and 2012 showed that a low yet detectible number of samples from replanted mini-greens were positive for the research strains inoculated on the previous crop.

Other trials conducted by Suslow and Koike address whether cultural changes implemented by growers can reduce a pathogen’s life span.

Suslow said, “Our preliminary findings suggest that delaying residue disking for at least a week after harvest, especially if the field is believed to be contaminated, allows existing environmental conditions to reduce pathogen numbers naturally.”

Commercial sponsors of the 23rd annual Fall Desert Crops Workshop included: Platinum Level – BASF and Bayer CropScience; Gold Level – Dow AgroSciences, Oro Agri, Westbridge Agricultural Products, and Syngenta; and Silver Level – FMC and Valent.