Seeding density and lodging control using a calcium and potassium-based organomineral fertilizer in oat crops

Abstract

Technologies ensuring high crop yield and plant competitiveness without lodging can contribute to an efficient and sustainable management of oat crops. The objectives of this study were to evaluate the use of high seeding density in current oat cultivars grown in the northwestern Rio Grande do Sul (RS), Brazil; assess the effects of plant growth regulators on grain yield indicators, industrial grain quality, and stem structure; and evaluate a calcium and potassium-based organomineral product as a sustainable technology for controlling lodging. Two experiments were conducted in Augusto Pestana, RS, in a randomized block design. Experiment I (2021) was set up in a 4×3 factorial arrangement consisted of 4 oat seeding densities (100, 300, 600, and 900 seeds m-2) and 3 treatments with plant growth regulator (PGR) application (control; application of trinexapac-ethyl and organomineral product at the stage between the 1st and 2nd visible stem nodes). Experiment II (2022) was set up in a 4×4 factorial arrangement consisted of 4 seeding densities (100, 300, 600, and 900 seeds m-2) and 4 PGR application treatments (control; application of trinexapac-ethyl and organomineral product at the stage between the 1st and 2nd visible stem nodes; and sequential application of organomineral product at V4 and at the stage between the 1st and 2nd visible stem nodes). The results of both experiments showed the need for a higher seeding density (between 400 and 520 seeds m-2) than that recommended. High air temperatures and limiting soil water conditions increased the phytotoxic potential of trinexapac-ethyl in oat crops. Evaluations of the Ca and K-based organomineral product, as a sustainable technology for controlling plant lodging, requires further analysis in years with more favorable environmental conditions for oat crops.