Vegetables, fruits, medicinal plants, turfgrasses, flowers, and ornamental crops are known as specialty crops, and they are essential ingredients in Americans’ lives.
Fruits and vegetables are highly nutritious and can help prevent disease. Flowers and ornamentals add beauty and serenity to everyday life.
Specialty crops are in general both higher in economic value and more intensive to grow, per acre, than conventional crops. The labor involved in producing specialty crops creates jobs and economic opportunities, making them the third-largest contributor to the Texas agricultural economy.
Producers of each specialty crop encounter unique challenges in all aspects of production, from sustainable growth to disease control to economics and marketing. Texas A&M AgriLife researchers throughout the state are helping them meet these challenges.
The U.S. Department of Agriculture’s Specialty Crop Research Initiative (SCRI) began in 2008 as an outcome of the Specialty Crops Competitiveness Act of 2004. The act is based on the idea that a competitive industry in the United States is necessary for an abundant, affordable supply of specialty crops. In 2014, the amount allotted by the USDA for the Specialty Crops Research Initiative increased from $55 million to $72 million per year.
No more ugly potato chips
Among the recipients of SCRI funding is an AgriLife Research team working to combat zebra chip disease in potatoes. When zebra chip disease emerged as a major threat to the Texas potato industry in the early 2000s, AgriLife researchers jumped to the rescue.
Potatoes are an important crop for Texas growers though only about 25,000 acres of potatoes are grown here, says Dr. Charlie Rush, professor of plant pathology at the AgriLife Research and Extension Center at Amarillo and national program director of the Zebra Chip SCRI Program, formed in 2008. “They just don’t compare at all to the millions of acres of wheat we grow. So it’s particularly important that these smaller crops are considered in a different category than the major crops,” Rush says.
Zebra chip is largely a marketing problem. Potatoes infected with the disease develop ugly black stripes when fried, even though they do not present a health risk to consumers. Texas potatoes are often used to make potato chips, but no chip manufacturer wants to sell an unattractive product. Texas growers were losing millions of dollars a year because of zebra chip disease by 2005.
To find ways to combat the disease, AgriLife researchers received one grant from the State of Texas and another through the SCRI. The two programs work closely together and have learned more about the disease. The researchers originally thought that the potato psyllid, the insect that transmits the disease-causing bacterium, migrated north from Mexico at the beginning of each growing season and could reach only a few southern states before cold winters killed them.
“In 2011, the disease was recorded in Idaho,” says Rush. “We discovered populations of psyllids overwintering as far north as Washington.”
Zebra chip has become a national problem. The initial five-year SCRI grant will end in August. Rush and his colleagues will submit a new proposal to get funding for the next five years.
Potatoes are among many specialty crops that can make up a delicious and nourishing diet, and some specialty crops come with an extra helping of health benefits.
“Particularly with the alarming increase in human diseases and obesity, more attention is being paid to the evidence that consumption of more fruits and vegetables balances health for human beings,” says Dr. Daniel Leskovar, professor of vegetable physiology and director of the AgriLife Research and Extension Center at Uvalde.
Among the scientists Leskovar works with is Dr. Kevin Crosby, associate professor of horticultural sciences at Texas A&M University. Crosby is developing new tomato varieties that are resistant to certain plant viruses yet have vine-ripe flavor, as well as new varieties of melons and peppers.
“Plant breeding requires collaboration in a range of disciplines,” says Crosby. “And there are a growing number of collaborations with medical scientists.”
Crosby is one of the faculty members in the AgriLife Research Vegetable and Fruit Improvement Center (VFIC). Part of the center’s work is to search for chemical components of specialty crops that are important for human health.
For example, Dr. Luis Cisneros-Zevallos, another VFIC faculty member and associate professor of horticulture at AgriLife Research, has recently shown that peach extracts inhibit breast cancer metastasis in mice. Cisneros-Zevallos and his collaborators saw this work published in the Journal of Biological Chemistry in March 2014.
“After determining the dose necessary to see the effects in mice, it was calculated that for humans it would be equivalent to consuming two to three peaches per day,” Cisneros-Zevallos said to an AgriLife Today reporter.
Specialty crops produce other public health benefits as well.
Lawns and flowers
There are documented cardiovascular and mental health benefits of spending time in natural environments, says Dr. Charlie Hall, professor of horticulture at AgriLife Research and Ellison Chair in International Floriculture in the Department of Horticultural Sciences at Texas A&M University.
Many AgriLife researchers study plants that add elements of nature and beauty to daily life.
For example, the turfgrass breeding program at the AgriLife Research and Extension Center at Dallas focuses on grasses that grow well in hot, dry climates, such as zoysia, Texas bluegrass, and St. Augustine. The program works closely with AgriLife researchers in College Station who focus on turfgrass ecology, physiology, and management. In 2010 the program received an SCRI grant for developing drought- and salinity-tolerant turfgrasses, working as part of a team of researchers at five major universities in the southern United States.
Like other specialty crops, turfgrasses must be stored carefully before being sold. Turfgrass growers must harvest sod from fields and deliver it to consumers before it begins to deteriorate. Close proximity of a turf farm to its market is crucial, says Dr. Ambika Chandra, assistant professor of turfgrass breeding and genetics at the AgriLife Research and Extension Center at Dallas, and director of the turfgrass breeding program there. Developing cultivars specifically for varied climates and soils helps local growers as well as the overall turfgrass industry.
Among the program’s many successes is a recently released water-efficient St. Augustine variety. Water efficiency is important since roughly one-third of all water used by southern cities is spent on irrigating lawns and gardens.
In general, many specialty crops require massive inputs of water, fertilizers, and chemicals, says Dr. Raul Cabrera, associate professor of ornamental horticulture at the Texas A&M AgriLife Research and Extension Center at Uvalde. These inputs must be properly managed to avoid damaging the environment, he says.
Cabrera works extensively with greenhouse and nursery plants, where “unfortunately, water and fertilizer efficiency is small,” he says. “If we don’t recapture and reuse those, we are potentially messing up the ecology and the quality of the waters and soils in the regions where we grow these crops.”
One of his projects in water efficiency is to study the use of graywater, or soapy water from showers and washing machines, to irrigate ornamental and landscape plants.
Leskovar is concerned with sustainability in growing vegetables. He has recently started testing eco-polymer biodegradable plastics as ground cover to retain moisture around plants, control weeds, and improve the overall performance of vine crops such as watermelon. He and his collaborators are also comparing different irrigation systems and production methods for a variety of leafy crops.
“In hydroponic conditions, we need five to ten percent of the water we would have used for growing in field conditions,” he says. “Lettuce, kale, and chards are all very well suited to hydroponic growth.”
“Changes in climate and management of the environment are causing huge impacts on our valuable natural resources,” Leskovar adds. “It makes sense to develop local or regional production that can get into the market more rapidly, thus reducing the high energy cost of transportation while maintaining freshness, taste, and overall quality. There is the opportunity to develop varieties that could be more adaptable to local climates.”
Increasingly frequent occurrences of extreme heat, droughts, and pesticide-resistant diseases underscore the importance of developing sustainable production systems.
For example, the Zebra Chip research team has been helping growers successfully control the disease using pesticides. However, pesticide-resistant potato psyllids have now appeared.
“We’ve realized that because of such widespread pesticide usage to control the potato psyllid in the United States and particularly in Mexico, we’re starting to see populations that are resistant to the commonly used chemicals,” says Rush. “That could be a huge problem for us.”