In recent years, there has been an increased interest in drugs based on bacteria of the genus , which have not only a fungicidal, but also a growth-regulating effect on plants. The nature of the effect of such drugs on the photosynthetic activity of plant leaves, especially of legumes, is still poorly understood. In this regard, in 2021–2024, the reaction of 3 varieties of seed peas ( L.) to the pre-sowing treatment of seeds with 2 laboratory samples of local A4 and 8A1-3 by the level of accumulation of photosynthetic pigments by leaves, comparing them with the action of the chemical mordant Pioneer, CS and the biological preparation Pseudobacterin-2 (the active agent is ) was studied in the field. It was found that the conditions of the growing year explained 41.8–67.1% of the variation in pigment content, the genotypic features of the studied varieties – 10.7–12.5%, seed treatment – from 1.1 to 2.5%. On average, in the experiment (4 years × 3 varieties), the stimulating effect of all the studied preparations on the accumulation of pigments in pea leaves prevailed. For Chl a, the effectiveness of the drugs decreased in the order of Pioneer (8.25%) – 8A1-3 (7.48%) – Pseudobacterin-2 (3.68%) – A4 (2.83%). For Chl b, the order of preparations was slightly different: 8A1-3 (15.37%) – Pseudobacterin-2 (13.70%) – Pioneer (11.27%) – A4 (8.45%). The stimulating effect of drugs on carotenoid content decreased in the order of Pioneer (8.98%) – 8A1-3 (8.40%) – A4 (3.48%) – Pseudobacterin-2(1.57%). The pigment complexes of pea leaves of the E-483 variety reacted best to seed treatment with preparations of local strains (depressive effect was noted only in 8.3% of observations), the reaction was slightly worse in the Falyonsky Yubileyny variety, where depression was noted in 20.8% of observations. Most often, the drugs led to a depression of pigment accumulation in the leaves of the Falyonsky Usatiy variety (38% of the experimental variants), the stimulating effect was manifested only in 19% of observations.
E. M. Lisitsyn (Wed,) studied this question.