EFFECT OF PRE-SOWING SEED TREATMENT ON BIOMETRIC TRAITS AND YIELD OF PEA AFTER DIFFERENT PRECEDING CROPS

Abstract

The need to conserve resources and stabilize yields makes pre-sowing treatment of pea seed with inoculants and fungicidal seed dressings a key element of adaptive technologies in the Northern Steppe. The aim of the study was to determine the effectiveness of pre-sowing seed treatment of field pea (Pisum sativum L., cv. Madonna) with various inoculants and fungicidal seed dressings, as well as their combinations under different preceding crops, and to quantify the contribution of biometric yield components to yield variation in the Northern Steppe of Ukraine. Field experiments were conducted in 2023–2025 on ordinary low-humus, medium-loam chernozem at the experimental farm of Dnipro State Agrarian and Economic University. The two-factor design comprised factor A – preceding crop (winter wheat, sunflower) and factor B – seed treatment: untreated control; fungicidal dressings Vibrance RFC, Redigo, Sferico, Avido (each at 1.0 L t⁻¹); inoculants Rizolain 3.0 L t⁻¹ + RhizoSave 1.0 L t⁻¹; Atuva 2.0 L t⁻¹ + Premax 0.5 L t⁻¹; and their combinations with fungicides. Sowing was carried out early spring at 1.3 million viable seeds ha⁻¹ (row spacing 15 cm) on a P30K30 background; crop protection followed label recommendations. Measurements included plant height, pods per plant, seeds per pod, seed mass per plant, and thousand-seed weight. Grain yield was adjusted to 14% moisture. With winter wheat as the preceding crop, the control yielded 2.53 t ha⁻¹; single fungicidal dressings increased yield by 0.10–0.15 t ha⁻¹, whereas inoculation without a dressing added 0.20–0.29 t ha⁻¹. The highest yields were obtained from inoculant + fungicide combinations: Rizolain + RhizoSave + Vibrance RFC – 2.90 t ha⁻¹; with Redigo – 2.88 t ha⁻¹; with Sferico – 2.89 t ha⁻¹; with Avido –2.87 t ha⁻¹. Yield gains were driven mainly by higher seed number per pod (3.8–4.2) and greater seed mass per plant (2.43–2.79 g), with stable or slightly higher (215–221 g) and a modest increase in plant height (1–3 cm). After sunflower, baseline yield declined to 2.28 t ha⁻¹ (0.20−0.30 t ha⁻¹ compared with wheat), yet the relative response to inoculation and its combinations was greater: the best variants reached 2.66–2.68 t ha⁻¹, effectively offsetting the negative predecessor effect provided residues were finely chopped and evenly distributed. The coherence between shifts in yield components and actual yield confirms the leading role of improved pod seed set and seed mass per plant in realizing the benefits of biological seed treatment. At an optimal seeding rate of 1.3 million viable seeds ha⁻¹ and under adherence to the standard production protocol, inoculation combined with a fungicidal seed treatment provided a consistent average yield increase of 0.25–0.37 t ha⁻¹, making this approach appropriate both after winter wheat and after sunflower. Practically, inoculation on the day of sowing (Rizolain + RhizoSave or Atuva + Premax) combined with one of the modern fungicidal dressings (Vibrance RFC/ Redigo/Sferico/Avido), while observing product compatibility and inoculant viability requirements, provides a balanced combination of early disease protection and enhanced symbiotic N fixation.