EFFECT OF ORGANIC AND CONVENTIONAL FARMING SYSTEMS ON SOME PHYSIOLOGICAL INDICATORS OF WINTER WHEAT

Leaf area index, biomass accumulation and yield are important traits affected by environmental factors. The objective of this study was to evaluate the effect of two different farming systems (organic and conventional) on leaf area index, biomass and grain yield. Twenty four wheat cultivars were planted during 2008/2009 and 2009/2010 under rainfed conditions at National Agricultural Research and Development Institute Fundulea, Romania, on a cambic chernozem soil. Crop farming system and cultivars strongly influenced leaf area index (LAI) in this study. The highest leaf area index was reached in conventional farming system, while the lowest ones were recorded in organic farming system for all cultivars and experimental years. In organic farming system LAI ranged from 1.87 (Flamura 85, 2009 year) to 3.02 (Dor, 2009 year), reflecting less favorable conditions of water and nutrients supply. The organic farming system produced less biomass than the conventional farming system. A significant correlation between biomass and LAI in organic farming system was found, while in conventional farming the correlation of these traits was not significant. The correlations between total biomass and yield, averaged on experimental years, were very significantly positive (r = 0.65*** in conventional system, 0.70*** in organic system), suggesting that a higher yield can be associated with a higher biomass accumulation in any crop management system.