ABOVE-GROUND BIOMASS OF SUNFLOWER PLANT UNDER DIFFERENT PLANTING PATTERNS AND GROWING CONDITIONS

Studies regarding the effect of different planting patterns are of great interest and importance, especially when they are performed in different growing conditions. Plant growth, plant biomass and plant yield are conditioned by factors such as row spacing and plant population, which are of great importance. The aim of this study was to identify how the planting patterns, respectively row spacing and plant population, associated with diferent soil and climatic conditions, and sunflower hybrid are influencing the above-ground dry biomass of the whole plant and of the plant components. Also, the objective was to identify the share of dry biomass on different plant components, as well as the moisture content of the whole plant and its components. The determinations were performed in the early dough - dough growth stage of the sunflower plants. Researches were performed in field experiments in the year 2013, in two locations from South Romania, respectively Fundulea (44o 28’ N latitude and 26o 27’56” E longitude), and Moara Domneasca (44o 29’ N latitude and 26o 15’ E longitude). The studied sunflower hybrids were the followings: Pro 111, LG56.62, P64LE19, Pro 953. Each hybrid in the two locations was studied under three row spacing (75 cm, 50 cm, and twin-rows of 75/45 cm) and three plant populations (50,000, 60,000, and 70,000 plants ha-1).