RESEARCH REGARDING INFLUENCE OF FERTILIZATION ON SUNFLOWER CROPS IN THE SOUTHERN PART OF ROMANIA.

Sunflower (Helianthus annuus L.) is the most important oil crop in Romania. Fertilization of sunflower crops has as a system a complex basic fertilization (NPK or NPK+S+Mg), used in preparing the seedbed and planting, who supports the normal coverage of the critical period of nutrition and laying the foundation of total yield. The aim of this research is to analyse the behaviour of sunflower under the influence of the degree of fertilization and also of the pedoclimatic conditions in the Oltenia Plain. Research was performed in the year 2018, in the southern part of Romania, within the Agricultural Research and Development Station Caracal (44° 06' N latitude and 24° 21' E longitude) in Olt County. For setting up the experience, the NEOMA hybrid was used in 6 test variants as follows: V1 - N0P0K0 (control); V2 - N90P0K0; V3 - N90P60K0; V4 - N90P60K60; V5 - N90P60K60 plus 1.5 liters/hectare of Fertigrain foliar fertilizer; V6 - N120P60K60. The doses used are in kg/ha of active substance. Plant population was 57.000 plants per hectare and the determinations were performed throughout the entire vegetation period of the plant, including the harvest period where the yield value was between 2.234 kg/hectare and 4.035 kg/hectare. Climatic conditions during the vegetation period were favorable, as the average temperatures have registered values between 16.3 and 24.3°C. The total rainfalls was 378.8 mm, those been sufficient for the favorable development of the sunflower crop. [ABSTRACT FROM AUTHOR]