Soil & Environ. 27(2): 223-227, 2008 www.se.org.pk Micronutrients status of plum orchards in Peshawar valley M. Tariq * , Z. Shah and A. Ali Department of Soil & Environmental Sciences, NWFP Agricultural University Peshawar, Pakistan Abstract A nutritional survey was performed to assess the micronutrients status of selected plum orchards in Peshawar valley. Representative soil (0-30 cm depth) and leaf samples were collected from 40 plum orchards during May 2008. Results showed that the concentration of AB-DTPA extractable Zn ranged from 0.04 to 1.34 μg g -1 , Mn 0.04 to 19.8 μg g -1 , Fe 4.8 to 21.0 μg g -1 , Cu 0.43 to 10.6 μg g -1 and available B 0.01 to 0.62 μg g -1 in soil. Based on soil test, Zn was deficient in 95%, B in 90% and Mn in 5% plum orchards. The leaf analysis showed that the concentration of Zn ranged from 19.6 to 99.9 μg g -1 , Mn from 20.2 to 77.8 μg g -1 , Fe from 11.0 to 158.0 μg g -1 , Cu from 2.60 to 74.0 μg g -1 , and B from 5 to 26 μg g -1 dry matter. Based on tissue test, Zn was deficient in 17%, Mn in 2%, Fe in 45%, Cu in 13% and B in 95% plum orchards. The soils of plum orchards were alkaline in reaction (pH 7.79 to 8.62), non-saline (EC 0.08 to 0.21ds m -1 ), low in organic matter (0.28 to 3. 04) and were calcareous in nature (Lime 4.70 to 22.5%). Present survey suggested that the plum orchards require special attention to overcome micronutrients deficiencies. Hence, the growers are advised to use micronutrients, specifically Zn and B along with other fertilizers for getting maximum yield and good quality plum fruit Key words: Plum, micronutrients, chemical properties, deficiency, critical level Introduction Plum (Prunus domestica L.) is an important stone fruit crop of NWFP and has great nutritional role in our daily food requirements. Plum is a source of minerals and vitamins (Gregory, 1993). It is grown in different areas of NWFP including Peshawar, Nowshera, Charsadda, Mardan and Swat areas. Earlier surveys of plum orchards indicated deficiencies of micronutrients in NWFP (Muhammad et al., 1995). Due to nutrient deficiencies, plum orchards are now turning into unproductive plantation, producing poor quality fruit. Moreover, soils of this region are low in organic matter content, mostly calcareous in nature and alkaline in reaction and these conditions are not favorable to micronutrients availability (Zekri and Obreza, 2003). Furthermore, appearance of nutrients deficiencies symptoms and responses to added nutrients indicated the prevalence of nutritional disorders of micronutrients (Zn, Cu, Fe, Mn and B) in NWFP (Rehman and Haq, 2006; Khattak and Hussain, 2007). In spite of the fact that the total quantities of micronutrients present in soil may be adequate, nutrients translocation does not match with growth or uptake, which can be clearly seen from the yellowness of young plum leaves. This phenomenon is very common in Pakistan in stone fruit plants, such as peach, apricot and plum, which are related to Fe deficiencies (Rehman, 1990). The formation of gum pockets is another common problem in plum, which is due to deficiency of B (Shorrocks, 1984). So far, no adequate information is available on micronutrients status of plum orchards in this region and role of micronutrients on the yield and quality of plum fruits. Therefore, present research was designed to study the prevailing micronutrients status of plum orchards in Peshawar valley and to compare the micronutrients status with the standard criteria for nutrient indexation. This study will certainly help in micronutrients recommendations for plum orchards that will optimize the financial returns of the plum growers. Materials and Methods A survey was conducted to assess the micronutrients (Zn, Cu, Fe, Mn and B) status of plum orchards in Peshawar valley during May, 2008. For this, 40 plum orchards were surveyed in Peshawar, Nowshera, Charsadda and Mardan areas according to the procedure described by Catara (1987). Representative soil samples from 0-30 cm depth and leaf samples from the crossing point (of which the soil samples) were collected from each orchard. During the survey, general observations on the appearance of plum orchards were also recorded and where possible relevant information from the concerned farmers were collected. Processing of samples Soil samples were properly packed, labeled and transferred to the laboratory of the Department of Soil and Environmental Sciences. After air-drying, twigs and stones were removed from soil samples, ground and passed through a 2 mm sieve and stored for laboratory analysis. Similarly, freshly collected leaves were washed with tape water and then with distilled water within 24 hours of sampling. After air-drying, the samples were oven dried at *Email: drtariqssc@yahoo.com © 2008, Soil Science Society of Pakistan (http://www.sss-pakistan.org)