The characteristics of spring cereals in changing weather in Estonia.

The objective of this investigation was finding ou t the impact of weather on yield, length of growing period, plant height, lodging res istance and protein content of spring cereals over 19 years (1991-2009). Two varieties per each c rop were selected for testing. Historical weather and crop yield data from the Jogeva Plant B reeding Institute were analyzed by the linear correlation analysis. To estimate the variat ion of grain yield, the minimum and maximum values, averages and coefficients of variation were calculated. It can be stated that the both stress conditions - drought and excess precipitation caused decrease of yield and quality of all the crops. The highest yields developed in 180-250 mm precipitation range from sowing to maturity. Oat re quires more moisture than wheat and barley. Significant positive correlation between the amount of precipitation and oat yield was found when three years of severe lodging were eliminated. Positive correlation between yield and plant height was found. In the years of severe lodg ing there was remarkable yield decrease of oat. Yield of oat and barley had negative correlati on with sunshine hours in June. The same correlation for wheat was not significant. Extra-lo w protein content for all the cereals, especially for wheat, formed in a cool year with th e lowest sum of sunshine hours during the whole growing period (2009). For oat and barley pos itive correlation between sunshine hours in June and protein content was found. For formation o f higher protein content, warm and dry weather conditions are required. Protein content wa s inversely associated with yield.