Evaluation of amino acid solution effects on amaranth accessions (Amaranthus hypochondriacus L.) productivity

Abstract

The effect of amino acids at a concentration of 10^-6 M on the formation of plant assimilating surface (using the variety K-63 as a model) is discussed. The experiment was carried out in the experimental field of the Research Institute of Biotechnology of the Gorsky State Agricultural University on leached chernozem of medium thickness with the following agrochemical characteristics: humus content - 4.45%; easily hydrolyzable nitrogen - 78 mg kg; labile phosphorus - 94.6 mg kg; labile potassium - 175 mg kg; soil pH value - 5.8. At the end of the vegetative growth stage, pronounced differentiation of plants regarding morphometric indices was observed. Proline and arginine were the most effective in stimulating shoot growth and branching increasing leaf area up to 34.9 thousand m² ha. Phenylalanine also produced a positive response with increases of 0.3–4.2 thousand m² ha compared to the controls. Phenylalanine proved to be the most universal stimulant providing a consistent yield gain of all studied accessions. Tyrosine at this concentration did not cause any significant changes compared to the control. Regarding a set of indices for the regional conditions, the variety K-63 was the best one that ensured the maximum yield of 62.34 t ha when treated with proline. The accession VR-99 was identified as the most productive in terms of photosynthetic potential with a growing season of 110–130 days. The research findings indicate that the application of amino acids intensifies vegetative biomass accumulation and forms a strong photosynthetic potential. Efficient C4 photosynthesis combined with a well-developed root system ensures high drought tolerance to the crop and supports stable biomass accumulation even under adverse hydrothermal conditions.