Morpho-physiological bases for productivity differences between paddy rice production regions in Santa Catarina

Abstract

This work was carried out aiming to identity morphological and physiological bases that help to explain grain yield
differences between two paddy rice production regions in Santa Catarina State (SC). Two field experiments were set, in the
cities of Itajaí and Pouso Redondo, SC, using the water-seed production system. Five genotypes were assessed at each place.
Main stem leaf area, disease incidence, flag leaf chlorophyll content, grain yield and its components were measured. The five
genotypes average productivity of grains was 11.4 t ha-1 in Pouso Redondo and 9.7 t ha-1 in Itajaí. The number of grains per
panicle was the yield component that better explained productivity differences between experimental sites. The larger main
stem leaf area, the higher flag leaf chlorophyll content and the lower disease incidence were morpho-physiological traits
that contributed to the higher productivities in Pouso Redondo. The greater solar radiation availability, the lower values of
maximum air temperature and the smaller air relative humidity content are environmental factors that probably contributed
to the higher grain yield of paddy rice in Pouso Redondo.