M. Yasin Ashraf, F. Hussain, J. Akhter
Nuclear Institute for Agriculture and Biology (NIAB), Jhang Road, Faisalabad, Pakistan
M. Ashraf
Department of Botany, University of Agriculture, Faisalabad, Pakistan
Department of Botany and Microbiology, King Saud University, Riyadh, Saudi Arabia
G. Ebert
Agricultural Advisory Department, K+S KALI GmbH, Kassel, Germany
Citrus is the largest fruit crop grown in Pakistan and Kinnow is the major planted species. About 94% of the total citrus is produced in the Punjab province (Sharif et al., 2005). Macro- and micro-nutrient deficiencies have been reported in citrus orchards of Punjab (Rashid et al., 1994). These deficiencies are usually recognized by distinctive symptoms that appear on the leaves and sometimes on fruits, branches or general growth of the tree (Ibrahim et al., 2007).
Sometimes, a combination of low or excessive amount may conceal characteristic symptoms of a particular nutrient and make visual identification more intricate. In such situations, leaf analysis is the tool that provides an accurate diagnosis on the basis of which necessary nutrient management can be suggested.Most of the Pakistani soils are calcareous with pH more than 7.0 due to the presence of calcium carbonate (CaCO3). These soils also contain a significant quantity of sodium (Na), which is harmful for plant growth and optimum productivity (Ibrahim et al., 2007). To have economical plant productivity on such soils, proper supply of potassium (K) along with nitrogen (N), phosphorus (P), and micronutrients is necessary.