Crop of the Week in Review: Romaine Lettuce and Grain Sorghum

*Romaine lettuce originated as a Mediterranean weed. Paintings in Egyptian tombs dating from about 4500 B.C. reveal a type of lettuce with long, pointed leaves, not much different from romaine lettuce. It was also grown and eaten raw or cooked in China in early history.As early as 55 B.C., romaine lettuce was served on the tables of Persian kings.

*The name romaine is the feminine form of "Roman" in French. It has a milky juice found in the ribs of its leaves. This is reflected in the first syllable of its Latin name, Lactuca, which means "milk."

*This lettuce has gained tremendous popularity in the past decade as the key ingredient in Caesar salads.

*In 2005, more than 20,000 acres of romaine lettuce was grown in Yuma County. Valued at about $160 million, romaine is the second most important type of lettuce grown in Yuma County, iceberg lettuce being the first. It is grown here for romaine hearts and for use in packaged salads.

*Romaine lettuce has a loaf-like shape with dark green outer leaves favored for its strong taste and crispy texture. The interior leaves of romaine are paler in color and more delicate in flavor. There is also a milder tasting variety with red-tipped leaves and a sweet romaine.

*Romaine lettuce's darker color indicates it is more nutritious and more flavorful than other lettuces. It contains lutein and xeazanthin, carotenoids that help keep eyes healthy. It is a good source of vitamins A and C and folate.

*Romaine lettuce can be kept in a refrigerator for up to a week after purchase. Do not store lettuce next to bananas, apples, pears or tomatoes as the ethylene these fruits give off will brown lettuce prematurely.

*Romaine is a member of the daisy family, which, although the second largest family of flowering plants, contributes to only a few food plants (including chicory, endive, escarole and dandelion). Sometimes romaine is also called cos or cos lettuce (mainly British) for the Greek island of Cos (Kos) off the coast of Turkey in the Aegean Sea.

*Lettuce juice was used as a medicine by many ancient herbalists. Roman Emperor Caesar Augustus put up a statue praising lettuce because he believed it had cured him of an illness.

---

GRAIN SORGHUM

*Sorghum is a tall, coarse annual of the family Gramineae (grass family). It is similar in appearance to corn, but the grain is located at the top of the plant rather than an ear on the main stalk.

*There are several types of sorghum, including grain sorghums, grass sorghums (for pasture and hay), sweet sorghums (for syrups) and broomcorn (for brooms and brushes).

*Due to an unusually extensive branching root system, sorghum is drought resistant and heat tolerant.One study showed that when corn required more than 30 inches of water, sorghum required less than 23 inches.

*Currently, 12 percent of sorghum grown in the U.S. is used to make ethanol. Byproducts from ethanol production, such as sorghum distillers grain, are also finding a place in the market as animal feed.

*Yuma County producers currently are growing about 1,000 acres of sorghum a year. That is expected to change with the proposed ethanol plant in eastern Yuma County. Backers of the plant say it would use about 100,000 acres of sorghum to produce 50-55 million gallons of ethanol a year initially.

*Sorghum is the world's fifth most important cereal, in terms of both production and area planted. It is crucial to the world food economy because the grain contributes to household food security in many of the world’s poorest, most food-insecure regions.

*Sorghum contains such valued nutrients as iron, calcium and potassium. Before the invention of daily vitamins, many doctors prescribed sorghum as a daily supplement for those low in these nutrients.

*Because it lacks gluten - certain proteins present in wheat, rye and barley - sorghum is considered safe for the 1 to 2 million people in the United States diagnosed with celiac disease, also known as gluten intolerance.

*Although breeding has resulted in better nutritional value of sorghum and better flavor, earlier sorghums had higher tannin levels that caused a bitter, astringent flavor. This was used as a deterrent to birds. These high-tannin sorghums are still grown where birds could cause significant losses.

*Sorghum fibers are used in wallboard, fencing materials, biodegradable packaging materials and certain solvents. Dried stalks can be used for cooking fuel and dye can be extracted from the plant to color leather. Milo (with bearded heads of yellow or whitish seeds) is a variety of grain sorghum.Another variety, Johnsongrass, was introduced to the U.S. as a forage crop but has become an invasive weed in this country.

*Grain sorghum has been found by archaeologists at sites originating as early as 8,000 years ago. It is probably indigenous to Africa, and is one of the longest-cultivated plants of warm regions there and in Asia - especially in India and China.

---

Source: Kurt Nolte is an agriculture agent with the Yuma County Cooperative Extension. He can be reached at knolte@cals.arizona.edu or 726-3904.