Management of water content of soil in cultivation of greenhouse cucumber (Cucumis sativus L, Nasim variety) in Isfahan- Iran

Measurement and control of water content of soil is an essential factor in irrigation management, to apply the best management practice for reducing water consumption and improving product quality. The water content of soil is an important factor in greenhouse where it is directly related to the total amount of water consumed for irrigation. Since cucumbers ( Cucumis sativus L, Nasim variety) is considered as the main and much used summer crop in Iran, which are extremely sensitive to adverse conditions particularly water stress, determination and supply of water is vital for this plant. To this end, maximum allowable depletion (MAD) should be determined. This experiment was conducted in the research greenhouse (Plastic Covered) of Islamic Azad University in Khorasgan, Isfahan, during a period of five months. This project was implemented in the framework of three 40, 60, and 80 cm bar water suction treatments with three replications using tensiometer. Before treatment application, water content of soil was determined in weight. MAD in 40, 60, and 80 cm bar treatments was 22, 32 and 50%, respectively. Statistical results and mean comparison demonstrated that MAD of 22 and 32% led to a significant yield increase (P<0.001), while MAD of 50% had the least yield. The results reveal that there was a significant difference between MAD of 22 and 32% in increasing leaf area index (LAI) (P<0.001). Key words: Maximum allowable depletion, greenhouse cucumber, tensiometer, leaf area index.