This work had as objective to test the analytical methods used by ANGELOCCI et al (1979), HELDWEIN (1983) as well as the proposed with adjustment for the summer in Santa Maria (Santa Maria I, II e III) in order to estimate the daily number of hours with air temperatures ≤ 10, 11, 12, 13, 14, 15, 16 e 17,0°C for December, January, February and March in Santa Maria, RS. The comparison between values directly obtained from the records and the values estimated by five analytical methods (ANGELOCCI et al, 1979; HELDWEIN,1983; Santa Maria I, II e III) were done in function of the daily average number of hours with temperatures lower than above cited values, determination, linear and angular coeficients obtained by the first degree regression equation among the real values (records) and the estimated. It was verifyed that is possible to estimate, with good precision the daily number of hours with air temperature ≤ 17, 16, 15, 14, 13 e 12,0°C using the analytical methods proposed by ANGELOCCI et al (1979) and Santa Maria III.
lower temperatures in summer; rice; flower fecundation
