Slavica Dudaš

The effect of biostimulant and fertilizer on “low input” lettuce production

Abstract Lettuce production in the winter on the Adriatic coast, especially in a non-heated plastic tunnel, requires longer cultivation and is characterised by lower head mass and yield. In these conditions, the effect of biostimulant Bio-algeen S-90 and fertilizer Megagreen on the production of the traditional winter lettuce cultivar ‘Four Seasons’ was tested. Both treatments showed a positive effect on the growth and total yield of winter lettuce, and decreased the share of non-marketable yield. Bio-algeen S-90 treatment increased the plant height by 61.5%, and foliar treatment with Megagreen by 60.9%, as compared to the control treatment. Equally, both treatments resulted in higher leaf numbers (47.7% for Bio-algeen S-90 and 37.2% for Megagreen). The head mass of lettuce treated with Bio-algeen S-90 and Megagreen was 30.3% and 25.0% higher than in the control treatment, respectively. Megagreen contributed more to chlorophyll and carotenoid content, while Bio-algeen S-90 elevated the amount of vitamin C and dry matter. The pH value of lettuce juice decreased after Bio-algeen S-90, while the mineral content (N, P and K) did not differ between the tested treatments. Lower nitrate content was detected after both treatments. The obtained results elucidate the effect of Bio-algeen S-90 and Megagreen on “low input” lettuce production.

Essential Oil Composition of Three Globularia Species.

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of Globularia cordifolia L., G. meridionalis (Podp.) O.Schwarz, and G. punctata Lapeyr. was characterized by GC‐FID and GC/MS analyses. Among the 33 identified compounds, the most abundant present in all investigated samples were oct‐1‐en‐3‐ol (2.9–47.0%), 6‐(1,5‐dimethylhex‐4‐enyl)‐3‐methylcyclohex‐2‐enone (8.2–40.9%), and fukinanolid (7.4–31.6%). Multivariate statistical analyses (PCA and HCA) of the hitherto studied Globularia volatile compounds confirmed to some extent the assumed phylogenetic relationships of the Globularia species studied, including the close relationship between the morphologically similar species G. cordifolia and G. meridionalis, but also evidenced several discrepancies in the current classification of Globularia species.

Effects of biodynamic production on growth and essential oil content in basil

Abstract The effects of a biodynamic sowing calendar on the growth (plant height, fresh herb yield, nodes number) and quality (percentage of leaf mass, essential oil content) of three basil species, Ocimum americanum L., Ocimum × hybrida and Ocimum basilicum L., represented by the cultivars ‘Rosso’ and ‘Eco Genovese’, were tested. Statistical analyses showed that the species had greater impact on the observed parameters than either the sowing date or the species and sowing date in combination. The species showed a significant influence on all five tested parameters, while sowing date and interaction of both factors significantly influenced plant height, leaf percentage and essential oil content. The best yield per plant was obtained for O. × hybrida and O. basilicum ‘Eco Genovese’. The lowest species O. × hybrida produced the highest amount of essential oil. »Nodes number« parameter most clearly separated the species, but not the cultivars. Even though O. americanum gave the tallest plants, it did not yield either the highest amount of fresh herb or essential oil. This species’ height was most consistent, considering the significant impact of biodynamic rhythm. Sowing date was not crucial for basil fresh yield; however if there is a need for taller plants with a higher percentage of leaf mass and more essential oil, sowing date needs to be controlled.