Irrigation requirements for plantains in seven ecological regions in Puerto Rico

Abstract

Consumptive use (CU, cm), net irrigation requirements (NIR, cm) and gross irrigation (GIR, cm) of plantains were estimated for seven climatic regions of Puerto Rico. Modified Blaney-Criddle model was used to estimate CU with the temperature and rainfall data of the Adjuntas, Corozal, Fortuna, Gurabo, Isabela, Lajas and Mayagüez agricultural experiment substations, Puerto Rico. CU was estimated for January planting and for 50% moisture depletion. For all locations minimum and maximum CU was observed in February and September. During the year, CU range was 5.56 to 12.52 cm for Adjuntas; 6.80 to 15.06 for Corozal, 7.54 to 16.41 (or Fortuna; 7.24 to 15.82 for Gurabo; 7.01 to 15.29 for Isabela; 7.04 to 15.47 for Lajas and 7.26 to 15.52 for Mayagüez. Daily CU range was 3.2 to 4.2 mm/day corresponding minimum at Adjuntas and maximum at Fortuna. Daily CU (mm) was 3.9 for Corozal, 4.1 for Gurabo, 3.9 for Isabela and 4.0 for Lajas and Mayagüez. For att locations NIR range (cm) was 2.64 to 5.61 at Adjuntas; 3.48 to 10.21 at Corozal; 6.53 to 10.52 at Fortuna; 4.62 to 9.22 at Gurabo; 4.17 to 9.18 at Isabela; 5.77 to 11.84 at Lajas and 5.79 to 9.17 at Mayagüez. Surface irrigation (efficiency 40%) duplicated water requirement (GIR) compared to drip irrigation (efficiency 80%). With the surface irrigation, annual GIR was 123.13 for Adjuntas, 197.48 for Corozal, 298.13 for Fortuna, 225.23 for Gurabo, 215.58 for Isabela, 263.25 for Lajas and 205.93 for Mayagüez. NIR was also estimated for 20% rainfall probability which would represent dry years.