For the experiments, a 5-m-long drip irrigation test
bench was built with the following characteristics: pulley system used to make a turn with the lateral line to obtain a 10 m long lateral line; width of 1.55 m, with space for four lateral lines; gutters for the return of water to a tank; 0.5-hp motor pump, 2.07 [m.sup.3] [h.sup.-1] at 100 kPa; built with steel profiles and lifting cables to change lateral line slope.
After tests of one hour irrigation by sprinkler, we carried out an irrigation test
for one and a half hour to corroborate the idea that the timer can operate with any time of irrigation.
The [F.sub.2] generation mean in the drip irrigation test was significantly higher than the [F.sub.1] generation mean.
The [F.sub.1] generation mean was significantly higher than the resistant parent in the drip irrigation test, but not in the subirrigation test.
Note that the data in table 3 are dependent on the field conditions at the time of the irrigation tests
and may be different for other irrigation events in the same field.
The interval irrigation tested
in this experiment were [??] i) one-day, (ii) two- days, (iii) 3-days, (iv) four-days, and (v) five-days interval.
The soil for the typical and winter irrigation tests
was an area of mixed Canez fine sandy loam (fine-loamy, mixed, superactive, thermic Ustic Haplargids) and Quay fine sandy loam (fine-silty, mixed, superactive, thermic Ustic Haplocalcids) with initial soil test levels of 48 mg [kg.sup.-1] p (NaHC[O.sub.3] extractant), 192 mg [kg.sup.-1] K (ammonium acetate extractant), 8.2 pH, 0.04 S [m.sup.-1] soluble salts, and 0.9% Na base saturation.