Organic oat production (Avena sativa L.) in the conditions of Northeastern Bulgaria

Abstract. The study took place in the period 2018 - 2020 in the village of Milanovo, Shumen region. In the period March 23 - 30, in accordance with the climatic factors of each year, the spring oat variety Scorpion was sown at a sowing rate of 3000 - 4000 germinating seeds per ha. Oats were sown after a predecessor crop of nettle. The aim of the present study is to prove that the oat variety Scorpio is suitable for organic production and it gives a quality product for direct consumption. The cultivation method and the finished product processing are also described in the study. The soil is gray-brown forest soil (Luvisols, Lessive - FAO UNESCO). Oats were grown following the requirements for field crop organic cultivation. In the period of vegetation, the crop was watered twice at a rate of 0.4 - 0.6 mᶾ /ha. The crop was harvested for green mass, at the maturity stage, as mowing was done in late June in two stages with a herb mower. The harvested area was 1.23 ha, and the green mass yield obtained was 10 t, on average for the period. The green mass followed a drying process in the sun, as a result of which 2470 kg of dry oat stalks were obtained. After that, we could prepare bundles measuring the length of 20 - 25 cm, packed in nylon and also aligned at the rear end. Each bundle weight varied from 100 to 300 g. After the dedusting process of bundles we were able to obtain a product for direct consumption showing fiber length of 0.4 - 3 mm. The sown area was identified as having the following groups of weeds: winter-spring (Chamomilla recutita Rauchert, Consolida regalis SPGray, Centaurea cyanus L. and Papaver rhoeas L.), early spring (Sinapis arvensis L., Bifora radians MB, Polygonum convolvulus L., Galium tricorne With, Avena fatua L.), ephemeral (Veronica hederifolia L., Stellaria media (L.), Holosteum umbelatum toothed swan) and root-shoot (Cirsium arvense Scop., Convolvulus arvense L. Cardaria draba L.). We could not detect any fungal disease attacks by: Puccinia coronata, Ustilago avenae, Ustilago hordei, Fusarium sp. Powdery mildew (Erysiphe graminis De Candole f. Sp. Avenae) and striped leaf spots (Pyrenospora avenae) had a weak effect on the crop (up to 25%). The study period showed the average content in the crop as follows: protein - 10.56%, starch - 43.62%, ash - 4.24%, and fiber - 13.47%.