Weather Conditions and Yield of Wheat in Bosnia and Herzegovina with Emphasis on Climatic Change and Tuzla Canton

Abstract

The aim of this study was to test the impact of monthly precipitation and temperature  regimes on winter wheat yields in Bosnia and Herzegovina (B&H) for the last 15-year period (2000-2014) with an emphasis on its administrative parts Federation of B&H (FB&H) and Tuzla Canton (TC:  from 2005-2014 period). Winter wheat is an important field crop in B&H, but yields are low, (average of 3.24 t ha-1) with very high variation among years (from 2.26 to 3.92 t ha-1). We estimated that yield differences are mainly due to weather variability. Average temperature in Tuzla (October-June) was 8.3°C in the last 15 years or 0.9°C higher than the 1961-1990 and 1925-1940 averages. Precipitation close to the 30-year average (663 mm, 642 mm and 636 mm) and their balanced monthly distribution characterized three growing seasons favorable for wheat (2007/2008, 2008/2009 and 2012/2013, respectively). Also, the temperature regime was without excessive cold or warm periods in these years. Under these conditions, wheat yields were considerably higher (3.7, 3.8 and 3.9 t ha-1, respectively) than in three estimated unfavorable years (2002/2003, 2009/2010 and 2013/2014 with 2.3, 2.7 and 2.9 t ha-1, respectively). Weather deviations as either drought or excessive precipitation in combination with high temperatures characterized estimated less favorable years. Tuzla Canton had about 5% of the national wheat harvested area, whereas yields were somewhat higher compared to the country average. Although it is evident that yields of wheat and weather conditions in B&H are very different between years, by performing simple correlation analysis there was found a minimal connection of precipitation and temperature with yields. Significant negative correlations were found only in level TC between yields and monthly values of precipitation in April (-0.88**), May (-0.70**) and total precipitation (-0.73**). Also, significant positive correlations were found between April (0.76**) and May (0.62*) temperature and yields.