Growers of tree crops apply a range of different nutrient management strategies. One of the simplest forms of nutrient management bases fertilization decisions on the ‘Critical Value’ (CV) concept, where fertilizers are applied to ensure that leaf nutrient concentrations exceed what has been determined as the critical concentration for good yield levels. In this approach, leaf nutrient analysis only provides an indication of adequacy or deficiency, rather than specific information on appropriate fertilizer rates or timing of applications. Fuente: Division of Agriculture and Natural Resources, University of California País: California, Estados Unidos