Wide Beds

Growers Maximize Resources by Boosting Bed Widths, Planting More Seed Lines per Acre

As Yuma area consumers deal with record-breaking gasoline prices, Yuma County produce growers not only cringe at the increasing cost of diesel fuel (used in tractors, irrigation pumps, spray equipment, trucking etc.), but also feel the unprecedented increase of almost every associated input cost. From newly implemented food safety guidelines, rising land lease costs, an unparalleled increase in the cost of nitrogen and phosphorus fertilizers, the continued effects of field labor shortages, and a general sense of market uncertainty, now more than ever, producers are seeking ways to trim production costs and gain greater efficiency.

While some Yuma growers are looking to maximize production with using less land, water, and inputs by planting multiple seed lines on a standard (42 inch) bed wider beds, others are pushing innovation further, doubling the size of the bed and increasing the number of seed lines along t.. Producers have been growing baby greens, spinach and lettuces for bagged salad mixes on 84-inch beds for quite a while, and now Romaine, Romaine hearts, head lettuce and even cauliflower are now being grown using wider 84-inch beds as well. Some view it as innovative because, almost instantly, a grower can see up to a 30% increase in production on the same piece of ground.

The practice is not new to vegetable producers in the Salinas area as it has been evolving for the past decade as a means toward more efficient use of resources, including land, water, and fertilizer. In recent years the transition has been accelerated with the development of specialized equipment to accommodate planting on 84-inch beds. Newly developed planters are now being used to precision-plant baby leaf varieties at 26 to over 36 lines on an 84-inch bed. The growing scheme has revolutionized spinach production in the Yuma area, allowing growers to produce consistent quality spinach along the entire bed. Growers plant high rates of seed, over 1.9 million seeds per acre, but can increase production by 25 percent to 50 percent while using the same amount of land and water.

Now that technology is being transferred into Romaine, Romaine heart and Iceberg production. Instead of the traditional 2 seed lines on a 42-inch bed, lettuce growers are converting planters to 84-inch bed configurations and are now placing 2 additional seed lines within the middle, increasing the total seed lines to 6 instead of 4 lines within the same planting area.

With emerging equipment, many growers in Yuma have also been experimenting with multiple seed lines along larger beds in head lettuce which could be an especially good fit for bulk lettuce production, where quality and uniformity are less important issues than in fresh-market head lettuce production.

Newer cultivation and fertilizer side dressing equipment specifically designed for 84-inch beds has also helped growers manage the production challenges associated with multiple seed lines. Before equipment innovations, growers typically used modified standard-bed planters and equipment to cultivate and manage the crop. As a result, the middle seed lines often were marred by poor drainage and, especially in the case of spinach, poor quality. By allowing growers to better work and prepare the ground, newer equipment has improved consistency of production across all seed lines within the bed.

The new production method has its challenges, however, and some Yuma area producers feel that the, “the jury still hasn’t returned its verdict.” With high density plantings, disease pressure is a larger factor, especially when the field is irrigated entirely by overhead sprinklers. In research trials conducted by the University of Arizona in Yuma, sprinkler irrigated lettuce grown on 84-inch beds also has been shown to have the lowest shelf life and greatest risk at harboring microorganisms. Effectively managing the high density center rows in a wide bed continues to challenge some growers in the area.

And, the production method has other challenges as well. Weed control is an issue, because hand crews have a slightly harder time hoeing middle seed lines, and as growers adapt to new weed management schemes, it’s currently not a production scheme suited for weedy ground.

However, the applied research and continued work on wide bed production is starting to provide good information to growers and help them make these high-production systems work in their fields. Moreover, despite the learning curve, it appears that wide-bed production appears to be a challenge growers are willing to embrace. If the increasing productivity on 84-inch beds is any indication, the seed, fertilizer, and other investments pencil out in cost savings associated with using resources more efficiently. As Yuma area producers find ways to master wide-bed production, the region will probably see an increase in popularity of head lettuce, romaine hearts, and other crops grown on these wider bed configurations.