Fertilization response and nutrient diagnosis in peach palm (Bactris gasipaes): a review

Peach palm (Bactris gasipaes Kunth) is a relatively new food crop with grea t potential for the humid tropics. Native to tropical America, it is commer cially grown to produce hearts-of-palm and, to a lesser extent, an edible f ruit. Peach palm is well adapted to nutrient poor, acid soils, and is culti vated in Brazil and Costa Rica on highly weathered soils with low pH, high aluminum saturation and, often, low organic matter content. Fertilization t rials on peach palm have shown significant responses to applied nitrogen wh ile the response to other nutrients such as phosphorus has been less freque nt. Additional research, however, is necessary to determine soil and foliar nutrient critical levels and to address questions concerning peach palm gr owth responses to nutrient additions varying in time and space. Recycled nu trients likely contribute significantly to peach palm nutrition because pla nt residues are produced in considerable amounts and can decompose rapidly in commercial peach palm plantation in humid environments where cut leaves and stems are left in the field following harvest. On the other hand, nutri ent exports from the system are relatively small (e.g., 4.8-6.4 kg P ha(-1) yr(-1), 28-32.3 kg N ha(-1)yr(-1), 31-45.2 kg K ha(-1)yr(-1)). As for most perennial tree crops, diagnosis of nutrient deficiencies in peach palm is l ess clear than in annual crops because of factors such as nutrient cycling, internal retranslocation, stand age, foliage age and position within the c rown, and seasonal and climatic variations. Some studies on peach palm have examined variation in nutrient content within leaves and plants, and among plants as well, but the sensitivity of different plant tissues to reflect changes in nutrient uptake and response to nutrient additions should be inv estigated in controlled field experiments.