Effect of foliar products on the inflorescence yield of lavender and essential oil

N. Minev¹*, A. Matev¹, N. Yordanova¹, I. Milanov¹, M. Sabeva² and M. Almaliev¹

1Agricultural University - Plovdiv, 12 Mendeleev street, BL4000 Plovdiv, Bulgaria
²Institute of Plant Genetic Resources ‘K. Malkov’, 2 Drujba street, BL4122 Sadovo, Agricultural Academy, Sofia, Bulgaria
*Correspondence: nikiminev@abv.bg

Abstract:

The topic of the effect of foliar fertilization on the productivity and oil content of lavender is relevant, but not sufficiently studied. The present study aims to establish the effect of foliar products on the growth, development and productivity of lavender. The field experiment was carried out at the Agricultural University – Plovdiv with lavender of ‘Jubileina’ variety during 2019–2020. The following variants were included in the study: 1. Untreated control; 2. Treatment with Fertileader Gold (FG) – 3 L ha^-1; 3. Treatment with Fertiactyl Trium + Fertileader Vital
(FT + FVital) – 1.5 + 1.5 L ha^-1; 4. Treatment with Fertileader Viti (FViti) – 3 L ha^-1; 5. Treatment with Fertileader Vital (FV) – 3 L ha^-1; 6. Treatment with Fertileader Alpha (FA) – 3 L ha^-1. Those preparations are bio stimulants for foliar application. The treatments were made in two consecutive lavender vegetation seasons. The first application was carried out in the second growing season (2019) and the second in the next, third growing season (2020). The foliar application of all tested products increased the photosynthetic activity, but it was better expressed when using the plant nutrition products FV, FViti and FT + FVital. A positive effect was also observed in the height and diameter of the bush, but during the third vegetation period. The number of flowering stems increased by 62.9%; 59.4%; 53.3% and 8.4%, respectively, when applying the fertilizers FG, FT + FVital, FViti and FV. The application of FG and FT + FVital increased the yield of fresh inflorescences by 6.1% and 3.7%. The application of the different products affected the oil yield in different ways; the application of FG, FT + FVital and FViti increased it, while FV and FA decreased it by 27 kg ha^-1 and 16 kg ha^-1, respectively, for the first vegetation and by 43.4 kg ha^-1and 33.1 kg ha^-1 for the second vegetation. The boron containing products FG, FT + FVital and FViti led to a significant increase in the essential oil yield, while the application of the foliar fertilizers FV and FA reduced it. Based on those results, the first three products are recommended.

Key words:

flower yield, foliar fertilization, Lavandula angustifolia, medicinal crops, oil content, oil yield

The effect of Lamiaceae plants essential oils on fungal plant pathogens in vitro

S. Lukošiūtė*, L. Šernaitė, A. Morkeliūnė, N. Rasiukevičiūtė and A. Valiuškaitė

Lithuanian Research Centre for Agriculture and Forestry, Institute of Horticulture, Laboratory of Plant Protection, Kaunas Str. 30, LT-54333 Babtai, Kaunas dist., Lithuania

Abstract:

Fungal pathogens Alternaria spp., Botrytis spp. and Colletotrichum spp. cause a significant loss of horticultural crops and their yield annually. The most convenient way for controlling diseases caused by these pathogens is the use of chemical fungicides. However, current practices still result in soil, water and air pollution, contribute to the loss of biodiversity and climate change, also are harmful to human health. Therefore, there is a growing demand for environmentally friendly plant protection methods. Herbs, especially, volatile oils, are a natural source of active ingredients. The findings of antimicrobial and antifungal activities, low toxicity, and biodegradability of essential oils make them potential for use in plant protection against pathogens instead of chemicals. This research aimed to evaluate the ability of Lamiaceae plants essential oils to suppress the growth of Alternaria spp., Botrytis spp., and Colletotrichum spp. in vitro. The study was carried out at the LAMMC Institute of Horticulture, Lithuania. Essential oils from lavender (Lavandula angustifolia) and thyme (Thymus vulgaris) were obtained by hydrodistillation and poured to potato dextrose agar medium at 200–1,000 μL L-1 concentrations. The radial colony growth of each pathogen measured after placing mycelial plugs of each fungus on Petri dishes. Results demonstrated that thyme essential oil significantly suppressed the growth of all three investigated fungal pathogens at concentrations starting from 400 μL L-1 7 days after inoculation as no growth of the pathogens observed. Meanwhile, lavender essential oil had lower antifungal activity than thyme. The most significant concentration of lavender essential oil was 1,000 μL L-1. To conclude, thyme essential oil showed high antifungal activity, and lavender essential oil showed moderate antifungal activity for our tested horticultural crop fungal pathogens. Both oils can be applied as one of the eco-friendly ways to control plant pathogens

Key words: