  The online version of this article (doi: 10.1007/s11240-016-1110-6 ) contains supplementary material, which is available to authorized users.  Meleksen Akin akinmeleksen@gmail.com 1 Department of Horticulture, Agricultural Faculty, Igdir University, Igdir, Turkey 2 Biometry Genetics Unit, Department of Animal Science, Agricultural Faculty, Igdir University, Igdir, Turkey 3 USDA-ARS-Retired, National Clonal Germplasm Repository, 33447 Peoria Rd, Corvallis, OR 97333, USA Received: 4 April 2016 / Accepted: 10 October 2016 © Springer Science +Business Media Dordrecht 2016               1   2   . 3 Plant Cell Tiss Organ Cult DOI 10.1007/s11240-016-1110-6 >2.012× DKW were the most critical factors for shoot quality. NH 4 NO 3 at ≤0.5× DKW and Ca(NO 3 ) 2 at ≤1.725× DKW were essential for good multiplication. RSM results were genotype dependent while CHAID included genotype as a factor in the analysis, allowing development of a com - mon medium rather than several genotype specifc media. Overall, CHAID results were more specifc and easier to interpret than RSM graphs. The optimal growth medium for L. cultivars should include: 0.5 × NH 4 NO 3 , 3× KH 2 PO 4 , 1.5× Ca(NO 3 ) 2 . Hazelnut · Mineral salts · Micropropagation · Mineral nutrition · Statistical an Growth medium salts, plant growth regulators, tempera and lighting are all key factors for improving in vitro pla growth. Tissue culture medium optimization studies ha traditionally focused on a few factors studied at the sa time, and based on simple ANOVA analysis or classical factorial designs. Factorial designs require a large numb of treatments, even when only a few factors are included (Compton and Mize 1999; Ibañez et al. 2003; Mize et al. 1999; Nas et al. 2005). Experimental designs and statistical analyses that are able to evaluate the effect of many factor with various levels and their interactions on mineral nut - tion of in-vitro plants are required for better optim process. New methodologies for improving in vitro shoot growt by changing mineral nutrients include using advanced statis - tical models such as response surface methodology (RSM) and neuro-fuzzy logic (Alanagh et al. 2014; Gago et al. 2011; Niedz and Evens 2007). RSM is a statistical technique Defning optimal mineral-salt concentrations for in vitro plant development is challenging, due to the many chemical interactions in growth media and genotype variability among plants. Statistical approaches that are easier to interpret are needed to make optimization pro - cesses practical. Response Surface Methodology (RSM) and the Chi-Squared Automatic Interaction Detection (CHAID) data mining algorithm were used to analyze the growth of shoots in a hazelnut tissue-culture medium opti - mization experiment. Driver and Kuniyuki Walnut medium (DKW) salts (NH 4 NO 3 , Ca(NO 3 ) 2 ·4H 2 O, CaCl 2 ·2H 2 O, MgSO 4 ·7H 2 O, KH 2 PO 4 and K 2 SO 4 ) were varied from 0.5 × to 3 × DKW concentrations with 42 combinations in a IV- optimal design. Shoot quality, shoot length, multiplication and callus formation were evaluated and analyzed using the two methods. Both analyses indicated that NH 4 NO 3 was a predominant nutrient factor. RSM projected that low NH 4 NO 3 and high KH 2 PO 4 concentrations were signifcant for quality, shoot length, multiplication and callus forma - tion in some of the hazelnut genotypes. CHAID analysis indicated that NH 4 NO 3 at ≤1.701× DKW and KH 2 PO 4 at 1 3