The effects of plant density and seed coating treatments on sunflower (Helianthus annuus L.) yield and quality properties

The aim of the present study was to determine the appropriate plant density per unit area in sunflower and to increase the yield per unit area using seed coating technology. It was carried out with the Tunca sunflower variety in 2018 and 2019 in Tokat-Kazova conditions. The study was carried out according to randomized complete block design in split plots arrangement with three replications. In the study, three plant densities (70x30, 60x30 and 45x30 cm) were in the main plots while 14 different combinations of coating procedures applied to shelled (film) and unshelled (pellet) sunflower seeds were in the sub-plots. In the study, the findings of emergence rate, plant height, stem diameter, leaf number, leaf area index, chlorophyll content, head diameter, seed yield per head, thousand seed weight, seed kernel and oil ratios, seed and oil yields were evaluated. According to the findings, as plant density increased, plant height, leaf area index, oil ratio, seed and oil yields increased while stem diameter, head diameter, chlorophyll content, yield per head, thousand seed weight decreased. In seed coating applications, film coating applications No: 7 (fungicide + insecticide) and 6 (hormones) came to the fore in terms of emergence rate, plant height, seed and oil yields. In these applications, the seed yield was highest 5.995 t/ha in the film application No: 7 (fungicide + insecticide), followed by film application No: 6 (hormones) with 5.920 t/ha as the average of two years. These two applications increased seed yields by %5 compared to the control group (shelled). Therefore, it was concluded that % 5 increase in seed yield in 45x30 cm plant density and film coating applications No: 7 (fungicide+insecticide) and No: 6 (hormones) could positively affect in large production areas.