Improvement of the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.) through foliar application of a nitrophenolate-based biostimulant

Application of biostimulants instigates many physiological processes that enhance nutrition efficiency, abiotic stress tolerance, and quality traits of crops, regardless of their nutrient content. One of such preparations is Atonik which contains nitrophenol compounds naturally occurring in plant cells. Several studies have confirmed its beneficial effect on the growth, development, and improved metabolic activity of plants. Therefore, it seems advisable to investigate the effect of Atonik preparation on the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.). The reported study was carried out in 2014 in Perespa, Poland. Over the growing season, Atonik was foliar-applied at a dose of 0.3 L/ha (0.1%) and 0.6 L/ha (0.2%) by single and double spraying of plants. Chlorophyll content and nitrogen status (N) were estimated by a Chlorophyll Meter SPAD-502 Plus. The foliar application of Atonik was found to improve the efficiency of the photosynthetic apparatus and chlorophyll content in the leaves of Dracocephalum moldavica plants, but the results were dependent on biostimulant concentration and number of its applications, and on the date of measurement. To conclude, Atonik is an environmental-friendly preparation which has a positive impact on the metabolic processes of plants.