Armstrong Research and Demonstration Farm
The asparagus cultivar trial was initiated in 1995 to evaluate the growing number of new hybrids for yield potential and suitability to Iowa growing conditions. The trial consists of a replicated planting at the Muscatine Island Research Farm, Fruitland (southeast Iowa), and observational plantings on ISU Research Farms at Kanawha (north central), Lewis (southwest) and Sutherland (northwest). Growing conditions at Fruitland include irrigation and a coarse sandy soil. The three observational locations are non-irrigated and have fine-textured loamy soils. Asparagus plots were planted with one year old crowns in rows 5 feet apart in 1996. Standard cultural practices were followed. Harvest and data collection started in 1998. Spears are harvested (snapped-off at ground level) when eight to 11 inches tall and are trimmed to an eight inch length before grading and weighing. Data presented are of marketable yield only. The trial evaluates 11 all-male hybrids including Geynlim, Greenwich and the ‘Jersey’ cultivars. Apollo, Atlas, Grande, U.C. 157 and Purple Passion are standard (dioecious) hybrids with both male and female plants.
Iowa State University
Lawson, Vincent, "Asparagus Cultivar Evaluation" (2001). Iowa State Research Farm Progress Reports. 1732.