Analysis of factors affecting spikelet sterility in flooded rice under field conditions in Chile

摘要

Spikelet sterility is one of the most limiting factors of flooded rice productivity in Chile. The 2004/2005 growing season was particularly cold, causing large yield losses. The objectives of the present work were to analyse the causes of the spatialvariability of spikelet sterility and evaluate the effect of some management practices on blanking. Meteorological data from the 2003/2004 and 2004/2005 growing seasons were analysed together with crop information from selected fields and experiments. Results indicated that the high level of spikelet sterility observed during the 2004/2005 growing season was due to low temperatures occurring during pollen formation and/or flowering. The large spatial variability was explained by the date on which pollenformation and/or flowering occurred in each field. Water temperature also determined differences in spikelet sterility. Fertilization and particularly N effect on spikelet sterility depended on the temperature present during pollen formation. Blanking levels increased with plant height.