ARI REVIEW FOR 2016-2017

AROMATIC AND MEDICINAL PLANTS Stevia field trials In 2017 a new stevia plantation was established at Zygi Experimental Station. From the four varieties examined in the previous programme, variety Candy was selected for the highest leaf production on dry weight basis. The same variety gave also the highest content in total sugars and the best ratio of rebaudioside A: stevioside. The aim of the new programme is to evaluate cultivation techniques which can increase fresh and dry yield and sugar production. The effects of different water regimes, cutting height and fertilisation frequency will be examined in respect to the productive parameters and the hydrophilic antioxidant activity of dried stevia leaves. Finally, economic analysis of the cultivation will be performed, and in the second year a demonstration field will be established. In 2017 two harvests took place. At the first harvest, the irrigation level affected significantly the plant production and the stevioside content but not the rebaudioside A content. Also, the fertilisation frequency affected only the stevioside content, while the cutting height factor affected significantly the plant height. At the second harvest, irrigation level affected significantly only rebaudioside A. Statistical difference resulted from fertilisation frequency only in plant height and fresh weight, whereas the cutting height significantly affected the concentration of stevioside only. Table 1 shows the effect of the irrigation level on the height, the fresh weight of the plants, the dry weight of the leaves, the rebaudioside A and the stevioside during the first and second harvest. Table 2 presents the results of t-test and Descriptive Statistics for plant height, fresh plant weight, dry leaves weight, rebaudioside A, stevioside by fertilisation frequency and Table 3 presents the results of t-test and Descriptive Statistics for plant height, fresh plant weight, dry leaves weight, rebaudioside A, stevioside by cut height. ( C. Stavridou ) Table 1 . Mean comparisons for plant height, fresh weight per plant, dry leaves weight per plant, and leaf sugar content, rebaudioside A and stevioside, at first and second harvest. Means within columns followed by different letters denote significant (P<0.05) differences according to Tukey HSD test. 19 Plant Improvement