The amazing life of lettuce ... from field to salad
Yuma County and the City of Yuma are most remarkable. Abundant water for agriculture and municipal/industrial use; soil that has been nurtured and cared for to be some of the most productive in the world; climate that allows for more than 100 crops to be successfully grown and a large skilled labor force that ensures that the food produced by the Yuma agricultural industry is safe, healthy and plentiful.
Let’s follow a head lettuce seed as it becomes a salad on someone’s table. The first step is the seed itself which is bred to become a large head of fresh lettuce. Seed companies carefully breed the seed to match the climate and soils it will grow in. The seed is coated with a little fertilizer and fungicide to protect the seedling as it germinates. The seed is planted on fields that are as level as a pool table; rows made by a tractor working off of a satellite positioning system (GPS) to make them perfectly straight and planters also using the satellite system to put the seed into the beds.
Sprinklers are used to germinate the seed and depending on temperature, the little plants are up in 48 to 72 hours. Weed control chemicals are used on the field to reduce plant competition with the seedlings. Weed control also reduces the possibility of damaging insects and diseases from getting a foothold in the lettuce field.
Thinning the young plants comes next, at the 4 or 5 leaf stage. This presently is mostly done by farmworkers who walk through the fields using hoes to leave the strongest looking plants about 12 inches apart. There is a great deal of skill needed for this seemingly routine task. Workers look for the best plant to leave for maximum yields at harvest. Growers and packers depend on the worker’s dedication to their job.
With a field of evenly spaced lettuce seedlings, the next field operation is fertilization and tillage. Again, with the perfect (as humanly possible) rows and seed lines, equipment has been developed to deliver the needed nutrients on either side of the seedling rows without disturbing the plant. The plants are now being water with flood irrigation since the sprinklers used in germination were removed just before the thinning.
Depending on the variety of head lettuce being grown and time of year, in 75, 90 or more days, the heads of lettuce are ready for harvest.
At this time, mechanical harvest of head lettuce is not practical but the technology is being developed. Food safety now becomes the major concern. From the harvest equipment, harvest crews, field transportation of people and product and the coolers and shipping, a written record is kept of the measures to keep the lettuce free of contamination. All of the harvest aids (machines) seen in the fields are sanitized at the beginning of each day. Workers are required to wear clean clothes, hair nets, gloves and only use tools provided by the harvest company. Crew leaders check on the health of their workers. Sick workers are not allowed to work. All personal items are left on the crew bus. Jewelry, hair pins or other items that might fall into the field are forbidden.
Workers wash their hands before, during and after their work shifts. If a knife is dropped in the field, it is sanitized in a bucket of chlorinated water before being reused. The food safety crew member checks the level of chlorine several times a day for proper levels.
Part of the worker duties is to look for animal prints, garbage, leaking fluids from equipment, insect or bird damage and fecal material. Depending on the level of the contamination in a field, harvest may be restricted within 5 feet to 50 or more feet.
Our lettuce head is one of the lucky ones that make it from the field to the cooler, where it is chilled to 48 degrees or so and placed in a cold room. Product is normally on the road to the buyer within 24 hours of harvest. Crops are cut on a daily basis to fill the current orders to maintain maximum freshness and quality.
If our lettuce head isn’t being shipped across the United States or abroad, it may go to one of the 10 salad plants that operate in Yuma. Each plant needs 2 million pounds of lettuce on a daily basis, both romaine and head type. If our head weighs about 2 pounds, it takes a million heads per salad plant for daily orders.
Thinking back to our harvest crews, it seems incredible that the 25,000 to 30,000 workers who are daily in the fields can accomplish the job along with all the cabbage, broccoli, cauliflower, herbs, leafy greens, kale and dozens of other products grown and harvested in Yuma County daily with no food safety events.
Agriculture grows Yuma and it is the amazing growers, workers, packers, shippers, coolers and truckers that make us so successful. Thank you!