Deficit Irrigation Analysis of Red Pepper (Capsicum annum L.) Using the Mathematical Optimisation Method

Abstract: The objectives of this study were to analyse deficit irrigation with the mathematical optimisation method using the water-yield relationship and cost functions of red pepper, and to determine alternative deficit irrigation water levels. For this purpose, the effect of 5 different irrigation levels (I1, I2, I3, I4, and I5) on dry yield (DY) was determined using a line source sprinkler irrigation system in Kahramanmaraß, Turkey in 1999 and 2000. The average water amounts applied with I1 (non-water stress treatment) and I5 (water stress treatment) for the 2 years were 913 and 296 mm, and I2, I3, and I4 varied between these extremes. The quadratic production and cost functions were established between the average irrigation water and DY, and between water and total costs, respectively. Maximum irrigation water (Wm), economically optimum level of irrigation water for land-limiting (Wl) and water-limiting (Ww), and equivalent deficit level for land-limiting (Wel) and water-limiting (Wew) for red pepper yield were calculated a