Frequency of pathogenic fungi on alfalfa seed of different age

The presence of pathogenic fungi species on seed of six alfalfa cultivars (K-22, K-23, K-28, NS Banat, NS Mediana and Zaječarska 83) of different seed age (24 months and 108 months) was analyzed in this study. In studied cultivars, except in K-28, on older seeds, less fungi genera were identified compared to younger seed. Seven fungi genera were identified: Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium, Rhizopus, Stemphylium and sterile mycelia present in percentage from 0 to 6.5%. Alternaria species were identified on younger seed with 0.5% in cultivars K-28 and NS Mediana, 0.75% in K-22, 1% in Zaječarska 83 and 1.25% in cultivar NS Banat. In cultivar K-28, Alternaria species were identified in percentage of 0.25% on older seed. Aspergillus species in percentage of 0.25% were identified only in younger seed of cultivar NS Mediana. Cladosporium species were identified on younger seed in the percentage of 0.25% (NS Mediana), 1% (K-23 and NS Banat) and 6.5% (K-22), and on older seed in percentage of 0.5% (K-23, K-28 and NS Banat). Genus Fusarium was identified in percentage of 0.25% on younger seed of cultivar K-22. Genus Penicillium was identified in the range from 0.25% (K-22) to 0.5% (K-28) on younger seed and from 0.25% (K-22) to 1.75% (NS Banat) on older seed. Genus Rhizopus was identified in cultivar K-28, on younger (0.5%) and older seed (0.25%), and in cultivar Zaječarska 83, only in younger seed with 0.5%. Sterile mycelia was identified on younger seed of cultivars K-22 (4.5%), NS Banat (1.75%), K-23 (1.0%) and Zaječarska 83 (0.5%), and on older seed of cultivars K- 23 and K-28 with 0.25% and K-22 with 0.5%. Genus Stemphylium was identified in percentage of 0.25% only on younger seed of cultivars K-22, K-23, NS Banat and NS Mediana. Results of these analysis indicated favourable health condition of seeds of different age of analyzed alfalfa cultivars, especially in relation to economically important fungi genera Fusarium and Stemphylium.