Tillage System and Seeding Rate Impact on Yield, Oil Accumulation and Photosynthetic Potential of Different Cultivars of Safflower (Carthamus tinctorius L.) in Southern Russia

Abstract

Safflower (Carthamus tinctorius L.) is a high-value oilseed crop with growing importance in numerous countries around the globe. This study was performed to evaluate the efficacy of the basic tillage technique and various seeding rates on the yield, oil accumulation and photosynthetic potential of different safflower cultivars (Kamyshinskiy 73, Zavolzhskiy 1 and Alexandrite) in the Volgograd Region of Southern Russia. Three field experiments were conducted at the research farm of Volgograd Agricultural State University during 2018–2020. The treatments were arranged as split plots based on a randomized complete block design with three blocks. Tillage treatments (basic tillage as the control (moldboard PN-4-35, depth 20–22 cm), chisel ploughing (OCHO 5-40, depth 35–37 cm) and disc ploughing (BDM-4, depth 12–14 cm)) were assigned to the main plots, and seeding rates (200, 300 and 400 m2/m2) were allocated to the subplots. The maximum leaf area, with a value of 26.35 m2/m2 and the greatest photosynthetic potential of 1489 thousand m2 × day ha−1, was obtained in Alexandrite with the interaction of deep chisel ploughing and a seeding rate of 400 thousand seeds ha−1. The highest dry biomass was also achieved in Alexandrite, with a value of 3.24 t ha−1, with the interaction of deep chisel ploughing and a seeding rate of 400 thousand seeds ha−1. The highest yield (1.84 t ha−1) and oil accumulation (28.75%) were recorded for Alexandrite with the interaction of deep chisel ploughing and a seeding rate of 300 and 400 thousand seeds ha−1 respectively. Overall, in terms of tillage treatments, the safflower productivity was highest when chisel tillage was performed, and the lowest yield was observed with the small disc ploughing practice. The yield of Alexandrite cultivar was noted to be 4.4–4.8% higher than that of the Zavolzhsky cultivar and 9.2–10.8% higher than that of the Kamyshinsky 73 cultivar.