EFFECT OF CONTROLLED WATER REGIMES ON PUMPKIN GROWTH

Pumpkin, Cucurbita moschata (Duchesne) Poir, is one of the most important vegetables crops in the Caribbean Basin. Vegetables production in Puerto Rico tropical areas depends on drip irrigation for most of its irrigation requirements. However, information on basic drip irrigation management practices is still inadequate. Therefore, a research was conduced using Pan A evaporation readings, to establish drip irrigation management practices and quantify resulting crop response. The objectives of the study were: 1. To evaluate the effect of evapotranspiration replenishment on growth of pumpkins under tropical conditions, and 2. To determine water requirements for pumpkins under tropical conditions. Pumpkin plants (Soler and Isolate Summer selections) were submitted to four evapotranspiration replenishment treatments (ERT): 25, 50. 75, and 100% of Pan evaporation readings at two locations, Lajas and Juana Diaz. ERT did not affect leaf area at any of both locations. However, the dry matter accumulation was affected significantly by ERT, pumpkin selection and interaction of both main effect at Juana Diaz. The estimated evapotranspiration (100% ERT) at Juana Diaz (5.1 mm day1) was twice as great as that of Lajas (2.4 mm day-1).