نوع مقاله : مقاله پژوهشی
نویسندگان
1 محقق مؤسسه تحقیقات خاک و آب،
2 عضو هیأت علمی مرکز تحقیقات کشاورزی یزد
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Plant analysis is a useful tool in monitoring nutritional status, recommending fertilizer rates and types, and maximizing fertilizer efficiency, if the chemical analysis results are correctly interpreted. Diagnosis and recommendation integrated system (DRIS) approach is a comprehensive system which does not have limitations of the critical value approach (CVA) and sufficiency range approach (SRA). Pomegranate (Punica granatum L.) is one of Iran’s commercial tree crops for which there is no sufficient data available for making fertilizer recommendations. In this investigation the amount of nutrients in leaf samples and yield from 151 pomegranate orchards throughout Yazd province were determind for two years (1996-98). According to the DRIS technique, the whole population was divided into two groups based on yield performance as high and low yielding sub-population with deviding line of 14 t ha-1 yield. The mean of each sub-population was calculated for various forms of expression. Variance ratios between yield of sub-population for all forms of expressions were calculated along with the coefficient of variation (CV). In order to select the best reference norms two factors were taken into account involving the largest of variance ratio (SB/SA) and the concentration of elements during growth stage. 45 reference norms were selected. DRIS indices for N, P, K, Ca, Mg, Fe, Mn, Zn and Cu were calculated using Quick Basic and Excell softwares. These reference norms as well as the DRIS indices are useful in determining nutritional problems of pomegranate trees.
کلیدواژهها [English]