Effect of the Pătârlagele Diatomite on Seed Germination and Growth of Sunflower Plants

Sunflower (Helianthus annuus L.) is the third largest agricultural crop in Romania, after corn and wheat. In 2021 Romania cultivated 1112 thousand ha of sunflower with a production of 2818 thousand tons, ranking first among EU countries both in terms of production and cultivated area. Diatomite, also called diatomaceous earth or kieselguhr, is a natural sedimentary rock with a high content of silicon dioxide and clay minerals, widely used in agriculture for its insecticidal and fungicidal properties, stimulating the process of seed germination and plant growth, as well as the ability to absorb and retain nutrients and water. The paper presents preliminary results regarding the effect of diatomite from Pătârlagele deposit (Buzău County) on seed germination and growth of young sunflower plants in laboratory conditions and on seeds production in the field at three sowing dates as well. A semi-early hybrid P64LE99 was used in experiments. Our data showed that the Pătârlagele diatomite improves sunflower seed performances both in laboratory and field conditions. In the laboratory, an increase in seed germination and stimulation of plant growth and development were observed in the diatomite treated samples compared to the untreated control. In the field under climatic and soil conditions of the Moara Domnească area (Southern Romania), the diatomite treated samples performed better than the control, both in terms of plant growth and development as well as production elements, in three sowing dates, middle and late April and early May. The highest yields were when sowing was in the first week of May for both variants.