Grab your fork and bowl
So what should we put in our salad? Let’s start with lettuce, low in calories, high in chlorophyll and vitamin K. Iceberg lettuce is also a good source of choline while Romaine lettuce provides vitamins A, B1, B2, and C, folic acid, manganese and chromium. Darker leafy greens are even richer in nutrients, so choose your variety widely and often!
The UC Davis Department of Plant Sciences plays an important and ongoing role in the production of lettuce, one of the 10 most valuable crops in the U.S. Its annual value is over $2 billion and 80 percent of it is grown in California. Lettuce is often grown over large areas, making it vulnerable to disease. Department researchers help growers stay ahead of evolving diseases by providing a whole host of production and pest-management tools as well as developing disease-resistant germplasm from which new varieties can be grown. Postharvest technology experts help growers get lettuce to market quickly and safely so we can pile it into our bowls.
Trivia question: How did iceberg lettuce get its name?
Answer: In 1926, Bruce Church, a University of California graduate and founder of Fresh Express, developed a way to ship his head lettuce from Salinas to the east coast by loading them in a train car and covering them with ice. As the lettuce-laden train cars rolled into the stations, folks would call out, “The icebergs are coming, the icebergs are coming!”
Tomatoes will be more plentiful come summer, but it’s hard to talk about salad without including this popular fruit (which most of us consider a vegetable). Botanically speaking, tomato is a fruit because it’s developed from the ovary in the base of the flower and contains the seeds of the plant (though cultivated forms may be seedless). But in the kitchen, we treat it like a vegetable, cooking it into dishes that are savory, not sweet.
No matter, the tomato is a nutritional powerhouse any way you cut it, loaded with vitamin C, vitamin A, potassium and lycopene, an antioxidant credited with preventing both cancer and heart disease.
As with lettuce, the department devotes many resources to tomato production, helping large- and small-scale growers, organic and otherwise, control weeds, manage pests, fight disease and tackle all the other adventures farming can bring. The department is also home to the C.M. Rick Tomato Genetics Resource Center, the largest known collection of tomato seeds in the world. You can’t breed a better tomato without a diversity of genetic tissue, and the repository and its abundance of wild species are the sources of resistance to 44 major tomato diseases and at least 20 insect pests – not to mention improved fruit traits like tolerance to saline conditions and drought.
Let’s add walnuts, “the nut of Jupiter” as the Greeks called them, food fit for the gods. Like almonds, pistachios and other nuts, they’re a good source of protein, fiber, phytonutrients and antioxidants. Nuts have a fair amount of fat, but it’s mostly the “good” fat, the omega 3 fatty acids shown to lower cholesterol. Department geneticists are showing that tannins in walnuts provide an added health boost (more on that later) giving us extra incentive to eat a handful of nuts every day.
California produces 99 percent of all the walnuts grown in the United States, the second-largest walnut-producing country in the world behind China. So we can thank California growers for the walnuts in our salad and California growers are grateful to the UC Davis walnut breeding program. Virtually all the walnut varieties sold in California nurseries are UC Davis cultivars. One variety – Chandler – accounts for 90 percent of those sales all on its own.
Our salad will benefit from a touch of orange – juicy and ripe with Vitamin C, beta carotene, folic acid, calcium, magnesium and potassium (just to name a few of its benefits!).
California’s citrus industry is currently under attack by a growing infestation of foreign pests, particularly a pest that transmits a bacterial disease called Huanglongbing or HLB. Trees infected with HLB produce bitter and misshapen fruit and, within short order, die. There are currently no control measures for HLB and three other deadly diseases. Department scientists are fast at work on a solution, so we (and the rest of the world) will be able to enjoy our oranges fresh and often.
To round things off, we’ll include a few olives, concentrated in monounsaturated fats (the good kind), a good source of vitamin E and a variety of phytonutrient compounds.
California is the only state in the nation producing a commercially significant crop of olives (about 75 percent of the national consumption comes from California). But the state’s olive industry is dwarfed by that of Spain. Harvesting costs are a huge burden for California olive growers, but there is hope on the horizon: A collaborative effort to develop the means to mechanically harvest table olives is about to bear fruit.