THERMAL AND HYDRIC CHARACTERIZATION OF SNAP BEANS FOR THE REGION OF FLORIANOPOLIS, SC, BRAZIL

The study aimed to determine the basal temperature, the heat units and the irrigation moment in snap beans growing, in order to provide opti mal water supply. Two variety groups were used: ''macarr (a) over tild e o'' and ''manteiga'', sowed at ten different periods spaced approxim ately 20 days. The experiment was designed in blocks (bands) with four replicates in each sowing period. Temperature, relative humidity and rain were measured. The matricial potential of the soil water was dete rmined by tensiometers installed at 10 cm depth. Phenological observat ions and radicular and foliar sampling were made, and the foliar area index was estimated. The heat units were estimated through the Degree- Days method, in which the basal temperature was estimated by the inter ception of X axis. The results showed that the basal temperature betwe en sowing and first harvest was 7.03 degrees C and 6.35 degrees C for ''macarr (a) over tilde o'' and ''manteiga'', respectively. Their heat sums were 954 and 1015 Degree-Days, respectively. In relation to the irrigation moment it was observed that until the third trifoliate leaf appearance, matricial potential accused irrigation requirement at abo ut -0.015 MPa, decreasing to -0.025 MPa at the beginning of flowering, and falling bellow -0.030 MPa during harvest.