Sunflower hybrid “Linzi” and its agronomic response to the main soil tillage systems in the region of South Dobrudzha

Abstract

Sunflower (Helianthus annuus – hybrid “Linzi”) yield obtained under different main soil tillage systems in 4-field crop rotation (common bean-wheat-sunflower-grain maize), is strongly influenced by the properties of the slightly leached chernozems the (Haplic Chernozems) and the climatic conditions. This study was carried out at the stationary field trial of Dobrudzha Agricultural InstituteGeneral Toshevo from 2016 to 2018. The influence of seven main soil tillage systems (MSTS) on the yield and the physical properties of sunflower seeds were investigated. The aim of this study was to trace the influence of different types of main soil tillage on seed yield, oil content and seed physical properties of sunflower hybrid ”Linzi”. Regardless of the meteorological conditions during the studied period, the main tillage systems are a powerful agrotechnical tool for managing sunflower productivity in all its aspects. The yield of seeds and kernels of hybrid ”Linzi”, as well as that of their oil content, is highest in years with a relatively favorable distribution of precipitation during the growing season. For the region of haplic Chernozems in Dobrudzha, the most effective systems for sunflower are the systems including the mould board plough of the soil. The best results were obtained when, in the 4-field crop rotation against wheat, deep tillage was replaced by Disking or No-till. The obtained oil yields are respectively: 2420.10 kg/ha (Plowing- -Disking); 2280.80 kg/ha (Plowing-No-till) 2244.70 kg/ha (Plowing-Plowing). The largest seeds were obtained in the under permanent shallow treatment against all crops in crop rotation - 62.66 g (Disking-Disking). The best results for the hectoliter weight were obtained in the two deep treatments with and without turning/inversion of the cultivated layer. However, the heaviest seeds were obtained when deep plowing is interrupted with direct seeding or disking, respectively. The positive correlation with the production of husks and kernels is strongly expressed. Averaged over the period, the correlation between the yield of seeds and that of husks has lower values compared to each of the years.