Determining the water requirement of rose cultivars in hydroponic greenhouse

 One of the solutions to reduce water losses in agriculture is proper irrigation planning, which is based on an accurate estimate of the water needs of plants. In order to determine the water needs of three rose varieties, a one-year study was conducted in a hydroponic greenhouse equipped with a drip irrigation system in Arak city using drained lysimeters. The amount of reference evapotranspiration using a drained microlysimeter with grass cultivation, the water balance method was used to calculate the water needs. The results showed that the total amount of reference evapotranspiration in the greenhouse during the one-year study was 1608 mm. Also, the total evapotranspiration of Atazhi rose during this growth period was 1423 mm, Pink Lip rose was 1480 mm, and White Rose was 1313 mm, and the average evapotranspiration of rose varieties throughout the year was 3.8 mm per day. Considering the age of the  bushes Rose, the vegetative coefficient did not have four stages and the vegetative coefficient value of Rose cultivars changed between 0.7 and 0.96 in each decade and the average vegetative coefficient of Rose cultivars throughout the year was 0.81. Also, the average amount of water consumed by the cultivars rose was obtained in one year, equal to 20,573 cubic meters per hectare, at a planting density of 75,000 rose plants per hectare.