Influência dos fenômenos El Niño/La Niña na produtividade de trigo no estado do Paraná. Influence of El Niño/La Niña in productivity of wheat in Paraná state.

by Prela, Angelica

The aim of this study was to verify the influences of El Niño/La Niña (EN/LN) in the regional yield of wheat in Paraná from 1976 to 2002. The yield and meteorological data were grouped in 6 regions, i.e., north, northwest, west, south, southwest, and central west. The technological trend of the yield series was eliminated to allow associations between the occurrence of the events EN/LN and the deviation of regional yield. Sequential climatological Thornthwaite-Mather water balance (SWC = 100 mm) on a 10-days time scale was used to detect the regional soil moisture conditions during the growth period in each year with large yield deviation. There was yield decrease in years of EN in the center-west and west regions, and tendency of yield increase in LN years in the south region. In the north, northwest, and southwest regions there was no significant effect of the EN/LN on the regional wheat yield.