THE EFFECTS OF TECHNOLOGICAL PROCEDURES ON THE FORMATION OF PHOTOSYNTHETIC APPARATUS OF FIELD PEA IN CONDITIONS OF WESTERN FOREST-STEPPE

Boosting field pea overall productivity comes with the increased photosynthetic activity. Due to theincrease in the size of the leaf surface, and the extension of the period of activity of leaves, stipules, andwhiskers of plants, the rate of solar radiation intercepted by crops, including field pea, rises.The aim of the research was to identify the influence of mineral fertilizers and growth regulators onthe leaf surface area dynamics and the formation of the photosynthetic potential of field pea varieties inthe Western Forest-Steppe.The experimental part of the work was carried out during 2016–2018 in the experimental field of theTraining and Production Center «Podilya» at the State Agrarian and Engineering University in Podilya. Thefield experiment was laid down in the research ten-digit crop rotation. The soil of the experimental fieldwas the typical black earth, characterized as deep, low-humus, and heavy gravel on forest-like loams.The results of the research indicate that the maximum leaf area indexes for field pea crops wererecorded at the micro stage BBCH 60-69. The largest leaf surface area was formed by the Chekbek peavariety. Leaf area ranged from 179.7 to 323.8 cm2 per plant, depending on the application of differentdoses of mineral fertilizers. Spraying of field pea plants (Gotovsky, Chekbek and Fargus varieties) at themicro stage BBCH 51–59 (budding — flowering) with growth regulators Plantapeg (application rate of25 g/ha), Emistim C (30 ml/ha) and Vimpel (30 ml/ha) had a positive effect on the formation of the leafsurface area and photosynthetic potential of the plant. On average, growth rates increased by 28–52%.According to the findings of the study, at the micro stages BBCH 60-69 some fertilization variantshave demonstrated doubling rates of the photosynthetic potential of plants. Therefore, the maximumphotosynthetic potential was recorded at the areas where mineral fertilizer N45P30K45 was inoculated incombination with the growth regulator Vimpel, which amounted 1.54 million m2/ha × day for the Chekbek field pea variety, 1.29 million mm2/ha × day for the Gotovsky field pea variety, and 1.25 millionmm2/ha × day for the Fargus variety.