Pakhshan Mustafa Maulood and Dalshad Azeez Darwesh 2020. Nutrient imbalance diagnosis in walnut orchards by using DRIS and PCA Approaches in the northern part of Erbil governorate-Iraq. Zanco Journal of Pure and Applied Sciences. 32, 6 (Dec. 2020), 14–24. DOI:https://doi.org/10.21271/ZJPAS.32.6.2.