بررسي اثرات كم آبياري روي محصول پنبه و تعيين تابع توليد در استان مازندران

The Study of the Effects of deficit irrigation on cotton yield and determination of water production function in Mazandaran province

In order to study the effect of deficit irrigation, estimate of yield function, improvement of water use efficiency and obtain the optimum yield of cotton, an experiment based on Randomized Complete Block Design (RCBD) consist of 6 water treatments with 4 replicates on cotton (Sahel var) was conducted in Baye-Kola Agricultural Research Station in Mazndaran Province for 2 years (2002. 2003). Analysis of variance and comparing 2 years experiments showed that the effect of irrigation treatment on cotton yield at 1% probability level was significant. The irrigation treatments were conducted based on. 0 . 25 . 50 . 75 . 100 and 125 percent of water requirements. Io treatment (zero percent of water requirement) and I3 (75% of water requirement) with the 1679 and 3099 Kg/ha yield had the minimum and maximum yield respectively. However, water use efficiency in Io and treatments were the maximum values. It is observed that in I3 treatment with 25% reduction of water requirement, there is no yield reduction and in I2 treatment with 50% water requirement reduction (comparing with perfect water use. I4 treatment), about 15% yield reduction was obtained. According to the results of this research, it is not necessary to irrigate the cotton with perfect water requirement and 50% of water requirement is sufficient.