Comparacion preliminar de dos metodos de diagnostico nutrimental en durazno, en Zacatecas, Mexico

This work was carried out in five municipalities of the State of Zacatecas, Mexico, and the objective was to evaluate peach nutrimental status with two diagnostic methods: 1) sufficiency ranges and 2) diagnostic and recommendation integrated system (DRIS). Leaf samples were collected from 80 orchards with no irrigation, selecting one tree from each orchard. Half of the samples were collected from high-yield orchards while the other half from low-yield orchards; fifty leaves was the sample size from each orchard. A representative soil sample was also collected. N, P, K, Ca, Mg, Fe, Mn, Zn, and B contents were determined on leaf and soil samples; and also pH, electrical conductivity (EC), texture, and organic matter (OM) content were determined on soil samples. Peach nutrimental status was determined by comparing leaf analysis results with: 1) sufficiency ranges and 2) the DRIS norms differences between high- and low-yield populations. No significant differences (P = less than or equal to 0.5) were found regarding texture, pH, OM content, EC, and nutrient concentration between high- and low-yield orchard soils. Ca and Mg showed a lower content in low-yield trees, nevertheless, soil samples showed no critical contents. Foliage nutritional status, determined by sufficiency range, was different from that of DRIS. In the first case, only Zn deficiencies were found both in high- and low-yield orchards. Study results showed significant difference (t Student) in Ca, Mg, and B. High yield trees showed higher foliar Ca and Mg concentration while low-yield trees showed higher B concentration; on the other hand, DRIS norms pointed out that Mg, Zn, Ca, and N were the nutrients with greatest variation and, therefore, the most limiting factors of peach production in Zacatecas.