Study of relationship between corn crop yield and water consumption in Mazandaran Province

In order to study the proper irrigation time of corn crop and determination of optimum management of water consumption in the limited water resource conditions، an experiment based on Randomized completed Block design with 3 replications was carried out in Baekola-Mazandaran agriculture research station during 2003-2004. Water treatment consisted irrigation levels based on 0 (Io)، 1 (I1)، 2 (I2)، 3 (I3)، 4 (I4) times irrigation، and 75 mm for each time was applied during growing season. Water treatments are defined as follows: I1: irrigation during flowering time I2: Irrigation during flowering and vegetative phaseI3: Irrigation during flowering، vegetative phase and tassel emergence I4: Irrigation during flowering، vegetative phase، tassel emergence and grain filling. The result of variance analysis and comparing the average of two years experiments shows that، the effect of irrigation treatment on corn yield was)P<0. 01 (significant. Io and I4 levels had the minimum and maximum yield) 2760 and 11210 kg/ha respectively (. The average water use efficiency (WUE) and irrigation water use efficiency (IWUE) are obtained 2. 43-2. 6 and 2. 72-3. 08، respectively، and the average yield response factor (Ky) for corn crop was determined 0. 99 in this area. I4 for no limited water resource conditions and I3 for 30% reduction of water consumption with 19. 7% of yield decrease in limited water resource can be used. The results of the experiments shows that، flowering stage is the most sensitive one comparing with others. Amount of water requirement in maximum yield is 300 mm. Then، based on obtained results we can decide on water recourses.