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 determined 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 dividing line of 14 t ha-1 yields. 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 Excel software. These reference norms as well as the DRIS indices are useful in determining nutritional problems of pomegranate trees.

Plant analysis is successfully used in monitoring nutritional status, recommending fertilizer rates and types, and maximizing fertilizer efficiency in sugar beet. Diagnosis and recommendation integrated system (DRIS) is a comprehensive approach which does not have limitations of the critical value approach (CVA) and sufficiency range approach (SRA). Over- dose application of fertilizer increases root yield but decreases crop quality. In this investigation, the amount of nutrients in leaf samples and yields from 383 fields throughout Khuzestan province were determined for three years. Then, database containing 5500 data including yields and concentration of nutrients was made. According to the DRIS method, the whole sampled fields were divided into two low and high yielding populations based on root yield of 53 tha-1 and white sugar yield 6.3 tha1. Then, all forms of expression were determined in each sub-population and the variance was calculated. In order to select the best reference norms, the largest variance ratio (SB/SA) was taken into account. Finally, 55 reference norms were selected. DRIS indices were calculated using Excel software. Mean concentration of NO3-N, N, P, K, S was 0.891, 3.98, 0.27, 3.16, 0.52 percentage and for Mn, Zn, Fe, Cu and B was 109, 34, 361, 16.5 and 40 mgkg-1. In order to check the precision, accuracy and usefulness of the norms and indices, the results of two fertilizer experiment were evaluated. The results showed that these reference norms as well as the DRIS indices seems to be useful in determining nutritional status of sugar beet.

Plant analysis is a useful and practical tool in monitoring orchards nutritional status, recommending fertilizer rates and increasing fertilizer efficiency, provided that chemical analysis results are correctly interpreted. Diagnosis and recommendation integrated system (DRIS) is a comprehensive approach for interpretation of plant analysis results which does not have limitations of the critical value approach (CVA) and sufficiency range approach (SRA). The aim of this study is to establish DRIS norms to interpret the results of peach tree leaf analysis. Leaf samples were collected from 61 peach orchards throughout the province during July of 2009 and 2010 and analyzed for N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu concentrations. On the yield basis of 30 Kg/tree, the peach orchards were divided into two groups of low (32 orchards) and high (29 orchards) yielding populations. An information databank with 7000 records including orchards yield and foliar nutrients concentration was developed.45 expression forms, based on the greatest variance ratio (SB/SA) and the foliar concentration of nutrients during growth stage, were presented as the best reference DRIS norms for peach trees, using the Microsoft ExcelÔ software. Average of nutrients concentration as a reference values for N, P, K, Ca and Mg and Fe, Mn, Cu and Zn were obtained 2.46, 0.24, 2.29, 2.03 and 0.56%, and 132.7, 32.5, 14.5 and 42.9 mg/kg, respectively. The Indices DRIS for the 9 nutrients were also calculated. The defined DRIS norms are applicable for the nutritional disorders diagnosis of peach trees.

The sufficient amounts of essential nutrients should be supplied for plants normal growth if the soil cannot provide them. For this purpose, it is necessary to find appropriate measurement method for determining the rate of nutrient deficiency. DRIS is an efficient method due to problems of nutrients concentration critical level and sufficiency limit methods, variations of these limits in different plant cultivars and climatic conditions, and dependence of results to sampling time. Thus, an experiment has been conducted in 61 peach orchards of Golestan province for two years (1388-1390). The orchards were divided into high and low yielding populations according to DRIS method (on the yield basis of 30 kg/tree); then, all expression forms, their variances in the two populations and variance ratios of the low (SB) to high (SA) yielding populations were determined. DRIS-derived sufficiency ranges originated from high yielding populations and taking into account variance ratios (SB/SA), which were 2.46, 0.24, 2.29, 2.03 and 0.56% for N, P, K, Ca and Mg and 132.7, 32.5, 14.5 and 42.9 mg/kg for Fe, Mn, Cu and Zn, respectively. The DRIS indices for the 9 nutrients were calculated in the low yielding populations using DRIS calibration formulas and Nutrient Balance Index (NBI) was determined for each of these orchards. Results indicated that the average order of nutrients requirement in the low yielding orchards is as following: Ca>P>Mg=Mn>K>Fe>Cu=Zn>N.

Nutritional balance is an important factor in increasing the yield and improving the quality of orchard production. The DRIS system is a suitable method for determining the nutritional balance status of orchards using leaf analysis. In order to recognize nutritional disorders in vineyards, a four-year (1997-2000) field experiment was conducted in Kohgiluyeh va Boyerahmad province. For this purpose, leaf analysis data from high yielding orchards were used to establish DRIS norms for grapevines. The norms obtained for N, P, K, Ca and Mg were 5.05, 42.7, 1.42, 1.7 and 0.4 percent in leaf dry matter and for Fe, Mn, Zn, Cu and B were 206.5, 110.3, 61.5, 14.6 and 33.9 mg/kg, respectively. The established norms were used to calculate DRIS indices and nutritional balance index(NBI) for those orchards having low yielding. The results showed that mineral nutrients were imbalanced in low- yielding orchards and Fe, Cu, Mn, N, K, Zn, B and P deficiencies were in 56, 56, 53, 44, 44, 41, 41, and 41 percent of this orchards, respectively. Based on the results, relative nutrient demands in low yielding orchards were obtained: Cu>Fe>P>Mn>Zn>N>Mg>K=B>Ca.

To determine DRIS norms for sweet lime trees in Fars province, yield and leaf analysis data (including N, P, K, Fe, Mn, Zn and Cu) were collected from 399 orchards (located in Jahrom, Darab, Fasa, Kazeroon and Firoozabad) and assessed in a period of four years. The results obtained were entered into a data bank. Nutrient data were expressed in different forms of DRIS norms and based on the yield data, orchards were categorized into low and high yield groups. Mean, coefficient of variation (C.V.) and variance (S) of different forms of nutrient expression were calculated for low and high yield orchards and the ratio of variance of low yield orchards to high yield orchards (SB/SA) was also determined. Those forms of nutrient expression that had highest SB/SA were selected as norms. The norms of leaf nutrients and the ratio between them were obtained for sweet lime as the following: N=2.66%, P=0.13%, K=1.71%, Fe=83.44 mg kg-1, Mn=30.89 mg kg-1, Zn=19.89 mg kg-1, Cu=6.62 mg kg-1, P/N=0.051, N/K=1.675, Fe/N=31.492, N/Mn=0.1, P/K=0.082, Fe/P=643.17, P/Mn=0.005, Fe/K=53.61, Mn/K=18.84, Zn/K=12.09, Fe/Mn=3.083, Fe/Zn=4.922, Fe/Cu=14.96, Zn/Mn=0.745, Cu/Mn=0.246, Zn/N=7.47, N/Cu=0.577, Zn/P=150.068, P/Cu=0.0267, Cu/K=4.32 and Zn/Cu=3.99.