Sunflower Yield and Yield Components under Different Sowing Conditions

The yield of achenes and the yield components of the head are specific to each sunflower hybrid, but they are influenced by the different growing factors (environmental and technological factors). Soil and climatic conditions are among the environmental factors with a great influence on the sunflower yield. Row spacing and plant population are of great importance among the technological factors. In this respect, the present study was aimed to study the influence of row spacing and plant population on yield of achenes and yield components of the head under different soil and climatic conditions from South Romania. Researches were performed in field experiments in the years 2013 and 2014, in two locations from South Romania, respectively Fundulea (44 degrees 28' N latitude and 26 degrees 27' E longitude) and Moara Domneasca (44 degrees 29' N latitude and 26 degrees 15' E longitude). In each location and experimental year there were studied four sunflower hybrids (Pro 111, Pro 953, LG56.62, and P64LE19), each of them under three row spacing (75 cm, 50 cm, and twin-rows of 75/45 cm) and under three plant populations (50,000, 60,000, and 70,000 plants ha(-1)). The row spacing influenced differently the yield components of sunflower head according to the soil and climatic conditions. The highest yields were obtained at row spacing of 75 cm under favourable growing conditions and at row spacing of 50 cm under less favourable growing conditions. The increasing of plant population from 50,000 to 60,000 and further to 70,000 plants ha(-1) decreased the values of yield components of the head. In the same time, the increasing of plant population increased the yield under favourable growing conditions and decreased the yield under less favourable growing conditions. (C) 2015 Published by Elsevier B.V.