Economic Responses of Broccoli and Cauliflower to Water and Nitrogen in the Desert

Abstract

Field studies were conducted to develop water and N response surface models for broccoli and cauliflower ( Brassica oleracea L., Botrytis Group) produced in the low desert of the southwestern United States and to estimate profit maximizing combinations of water and N over a range of realistic price situations. Marketable broccoli and cauliflower yields were increased by water and N inputs in all experiments. Generalized response equations indicate maximum broccoli yields with 43 cm of water and N at 267 kg·ha –1 and maximum cauliflower yields with 65 cm of water and N at 338 kg·ha –1 . Least-cost combinations of water and N changed with the costs of these inputs for yield levels below the economic maximum. However, profit maximizing N and water rates changed little regardless of input or crop prices investigated.