Water Resources Research Act Program

Principal Investigators: Dilip Nandwani

Abstract: Vegetables are important commercial crops for producers within the USVI and are grown for fresh market. The 2007 Census of agriculture for the US Virgin Islands indicates that production has decreased in many vegetables such as tomato, eggplant, okra, cabbage, squash, lettuce etc. since 2002. Fresh water resources, high cost of irrigation water, labor and management are major challenges in vegetable production. Though, islands are surrounded by water, the energy required to desalinate large quantities of water for farming purposes is truly substantial. The main water delivery system for crops grown for both research at the University of the Virgin Islands and by many U.S. Virgin Islands farmers is through drip irrigation. The use of drip irrigation is a great asset when it comes time for the application of fertilizers. Unlike the common local application of granular fertilizer, which is spread around the field or around the base of a sizeable plant, drip irrigation allows for the efficiency of applying water soluble fertilizers within inches of a relatively newly planted seedling and throughout the life of the plant. This allows for remediating specific nutrient deficiencies that can occur in some of our local high pH calcareous soils. Chemigation through drip irrigation delivers pesticides in the root zone of the plants. The precision obtained through drip application is safer, more accurate and uses far less material due to the accuracy. Using pesticides such as DuPont Coragen, Venom other commercial pesticides and soluble fertilizers are more efficient use of drip irrigation which saves in labor costs. This project proposes to use microirrigation as a highly efficient means of applying water and nutrients for high value vegetables. The water applied by drip irrigation can be scheduled efficiently by use of pan evaporation or tensiometers. Research information on irrigation requirements and management of vegetables is limited. Although some work on hot peppers with respect to microirrigation management is available, most recent information on microirrigation has been generated from experiments on the more commonly grown bell pepper. The objectives of the project are to develop and evaluate improved water management practices using microirrigation on the yield and growth of selected vegetables. It is expected that results of this project will assist farmers to improve their income by enhancing production of quality vegetables and saving costs in irrigation water. This baseline project will lay a foundation to adapt methods to improve cultivation of other economically important vegetables in the USVI using microirrigation techniques. Information obtained in this study will be released to the public through the Cooperative Extension Service personnel for use by local growers.