Leon M., Montalvo M. and Rojas N. Maximum and real evapotranspiration of the onion crop.
Research Institute of Irrigation and Drainage. Technical Report, 1987, Cuba.
In the Horticultural Experiment Station “Lillian Dimitrova” in the province of Havana, was studied the water needs of anion crop in soil red ferrallitic. The maximum evapotranspiration was determined in lisimeter of compensation type, real evapotranspiration was determined in plots distributed in randomized blocks. The timing of irrigation was established from the dynamics of the ETM and soil moisture in the parcel which was irrigated by the gravimetric method. It was found that the Maximum evapotranspiration of onion variety Red Creole is 400 to 480 mm. The real evapotranspiration ranges from 340 to 400 mm.
The total water net requirements is 2800 to 3200 m3 / h and the partial water requirements from 170 to 200 m3, the number of irrigation is 17 to 18.La soil wetting depth is 20 cm. from sowing until the formation of fruit and 30 cm. since the formation of fruit until the end of the crop cycle. The optimal timing of irrigation is achieved when soil moisture drops to 85% of field capacity, which is the economic limit where you get the best return. Bioclimatic evapotranspiration coefficients have values of 0.19 for the period from sowing to the establishment of plants, 0.35 for vegetative growth period, 0.55 for the formation of the bulb and 0.33 from the maturation until harvest.