THE EFFECT OF BONE MEAL ON THE YIELD OF JICAMA, PACHYRHIZUS EROSUS, IN OAHU HAWAII

Jicama is increasing in popularity in the United States as a specialty crop used in salad bars or in ethnic dishes from Asia and Latin America. For environmental reasons an in creased demand also exists to grow crops using locally avail able nutrient resources instead of using imported fertilizers. With this in mind, two experiments were conducted in separate locations to evaluate the effect of bone meal (BM) applications on the yield of jicama in Waimanalo, Hawaii. In one experiment treatments included a control, synthetic fertilizer, bone meal at a 1x (1 ton/acre) application rate, bone meal at a 4x rate, and bone meal at a 1x rate in combination with chicken manure. Each treatment was established in a 40 ft long double-row bed, replicated four times, with the plots arranged in a RCB design. The second experiment was conducted as part of a long-term organic farming study. Treatments included controls, low and high rates of compost alone, BM plus low or high rates of com posts, and synthetic fertilizer alone. Data collected included soil nutrient levels, stand establishment, top growth fresh weight, and root length, width, and fresh weight. High BM ap plication rates, and high compost/BM treatments affected stand establishment and depressed yields by 35%. Chicken manure and BM combinations resulted in the greatest yields and in the largest root sizes. Yields from the low BM applica tions treatments were similar to those obtained with synthetic fertilizers, which were in turn, similar or numerically greater