With the purpose of verifying if the irrigation system affects the common bean (cultivar
IAPAR-14) yield components (leaf area index, leaf disease incidence, plant height, number of beans per
plant and plant population) and the seed quality, a field experiment was carried out using furrow and
sprinkler irrigation at Agricultural Department, University of São Paulo, in Piracicaba-SP, Brazil. The
plant nutrition, and pest and weed control were optimized. There was no fungicide application. The
irrigation system was used to apply the accumulated maximum evapotranspiration, computed by Pan
Evaporation Method, each three days. The leaf area and leaf damage were evaluated at fenologic stage
R7 using computarized image analysis technique (by SIARCS software). At harvest time, the plant
height, number of beans per plant, plant population and yield seeds (moisture corrected to 12%). The
seed quality was evaluated by sanity (paper filter method), germination and vigor (cold test, first
germination counting, accelerated aging and field emergence tests). In the sprinkler irrigation system,
the incidence of Uromyces phaseoli and Phaeoisariopsis griseola was high, the yield was low and the
total and useful leaf area plant height, number of beans per plant and population were reduced. The
seed sanity evaluation allowed to verify that the incidence of seed pathogens was high under sprinkler
irrigation system, as Rhizoctonia solani mainly, where the germination and vigor were reduced. Therefore,
the common bean seed quality was superior under furrow irrigation system.