INTERACCION AGUA-NUTRIMENTOS EN TRES SISTEMAS DE PRODUCCION EN SANDIA Citrullus lanatus; (Thunb.) CON RIEGO POR CINTILLA Y ACOLCHADO PLASTICO

SUMMARY. Advanced irrigation methods seek to increase both, productivity and water use efficiency. Plastic mulches avoid soil evaporation losses increasing water efficiency and yield. This research was conducted in the experimental area of the National Center of disciplinary research on soil water plant and atmosphere relationships (CENID RASPA) during the spring – summer season 2000 with the objectives of determining yield increases, water use efficiency and to accelerate harvest in water melon. The study consisted of twelve treatments corresponding to a complete factorial experimental design with three production systems, two levels of nutrient applications with and without plastic. Findings show that the best replications were to transplant when the plant has two true leaves or when it has handlebars using plastic mulch and fertilizing with the formula 160–80–00 of NPK respectively. The production system of transplanting with two true leaves and fertilizing with 240–120–00 of NPK, also resulted in good yields ranging from 64.47 to 68.6 tons.ha-1. Water productivity ranged from 13.43 to 14.29 tons.Mm-3. The irrigation criteria was to replenish 60% of the daily evaporation which resulted in 48 cm depth of water. This results represent 134.43 and 149.2% increase compared with regional yields of 27.5 tons.ha -1 . The production system of transplanting in the beginning of handlebars and using plastic mulches, accelerates harvest for 11 and 18 days compared with transplanting with two true leaves and direct planting respectively.