INFLUENCE OF DOSES OF MINERAL FERTILIZERS AND CROPS AGE ON PHOTOSYNTHETIC INDICATORS OF GROWTH AND YIELD OF SEEDS SILFIUM PERFOLIATUM IN VEGETATIVE MULTIPICATION

Abstract

Mineral fertilizers influence positively the photosynthetic activity of plants and the seed productivity of silfium. Fertilizers contributed to the creation of optimal conditions for the growth and development of plants, the formation of reproductive organs and a high yield of seeds. Silfium crops in places develops the largest leaf surface and stay longer in the active state where doses of N₆₀P₉₀K₁₂₀ kg/ha and N₉₀P₉₀K₁₂₀ kg/ha were applied. Silfium showed an average seed yield of 293,8 and 301,7 kg/ha with this combination of doses of mineral fertilizers. When creating seed-growing crops of silfium perfoliatum and deficiency of seeds, it is advisable, especially in the weeded areas, to use the vegetative mode of reproduction. Planting with parts of bushes and rhizomes according to the planned scheme has the prospect of initially forming the optimal seeding density, facilitates the care and control of weeds, ensures seed production in the first year and high yields in following years.