IV International Symposium „Agrosym 2013“ 130 10.7251/AGSY1303130K GGE BIPLOT ANALYSIS OF WHEAT MEAN PERFORMANCE AND STABILITY AT DIVERSE LOCATIONS IN REPUBLIC OF MACEDONIA Mensur KAMBERI 1 , Dane BOSHEV 2* , Mirjana JANKULOVSKA 2 , Sonja IVANOVSKA 2 , Irfan AZEMOV 1 , Xhezair IDRIZI 3 , Ljupcho JANKULOSKI 2 , Biljana KUZMANOVSKA 2 1 Ministry of Agriculture, Forestry and Water Economy, Skopje, Republic of Macedonia 2 Faculty of Agricultural Sciences and Food, UKIM, Skopje, Republic of Macedonia 3 Faculty of Food Technology and Nutrition in Gostivar, SUT, Tetovo, Republic of Macedonia *(corresponding author: dbosev@yahoo.com) Abstract Wheat is the most important cereal crop in Republic of Macedonia. Development of genotypes that will have high grain yield with stable performance in different growing conditions is of paramount importance. The objective of this research was to evaluate and to quantify the magnitude of the genotype x environment interaction effects on wheat grain yield and to determine the winning genotype for the test locations. Ten wheat genotypes were tested at three locations (Skopje, Strumica and Prilep) for two years (2006 and 2007). The grain yield data for each location were subjected to the GGE biplot analysis. This analysis depicted the adaptation pattern of genotypes at different locations and discrimination ability of testing locations. Out of the three locations, Prilep was identified as the most discriminative and representative location. The genotype Bt 04-073 had the highest overall mean yield, and an average stability over different locations. In each location, Radika and Bt 04-073 were the closest to the “ideal” genotype, followed by Bt 04-024. Those genotypes can be recommended for production in wheat growing regions in Republic of Macedonia. Key words: wheat, genotype x environment interaction, GGE biplot, grain yield, stability analysis Introduction In the Republic of Macedonia, wheat is the most important cereal crop, grown on approximately 84181 ha in the last five years. Grain yield of cultivated genotypes in Macedonia is insignificantly higher (3056 kg ha-1) than the global average yields (3010 kg ha-1), but compared with the highest yield (7772 kg ha-1), it is far below this value (FAOSTAT, 2011). In order to mitigate this, different improved cultivars are continually created or introduced. Those cultivars are being evaluated at different locations to test their performance and to identify the best genotypes in specific environments. The genotype × environment (GE) interaction usually complicates the selection for improved yield (Sabaghnia et al., 2013). According to Rodriguez et al. (2002) in the cases when the magnitude of GE is large it impedes the selection of stable genotypes and the selection advancement is slow. Ceccarelli (1989) claimed that adaptation in crop plants corresponds to yield stability over time and environments. Considering this, when unpredictable GE interaction is present, cultivar evaluation must be carried out in multiple locations in order to fully test the target environment (Cooper et al., 2007). Consequently, for assessing genotypic value and cultivar’s stability for yield performance, multi-environmentl trial (MET) data are required. The main purpose of MET is to identify superior cultivars which could be recommended to farmers and to determine sites that best represent the target environment (Yan and Hunt, 2001).