Effect of Coated Urea Fertilizer on Yield and Yield Components of Sweet Corn (KSC 403) under Deficit Irrigation

This study was carried out to assess the effect of coated urea fertilizer on yield and yield components of sweet corn (KSC 403) under different irrigation regimes, in Ramin Agriculture and Natural Sciences University, Iran by using strip split plot in a randomized complete block design with four replications. Three levels of deficit irrigation (100%, 80 and 60% of calculated water requirement of sweet corn) were assigned as vertical factor and six sources of urea fertilizer (without urea, un-coated urea, sulfur-coated urea fertilizer, starch-coated urea, agar-coated urea and chitin-coated urea) were assigned to horizontal factor. Effects of deficit water and source of fertilizer were statistically significant on plant height, 1000 kernel weight, ear diameter, and number of rows per ear, ear yield, biological yield and harvest index. Maximum of plant height (153.23 cm), 1000 kernel weight (104.51 g), grain yield (9853.3 kg/ha) and biological yield (12471.6 kg/ha) were obtained in chitin coated urea fertilizer. Maximum of ear diameter (4.67 cm) and number of row per ear (13.22) were achieved in agar coated urea fertilizer and that of harvest index (45.79%) was indicated by starch-coated urea. Maximum of length of ear, number of kernels per row and grain yield were 23.65cm, 25.83 and 7142 kg/ha, respectively, and were obtained with the using of chitin-coated urea fertilizer and 100% water requirement. Minimum values of these traits were 13.54 cm, 5.56 and 871 kg/ha, respectively, and were obtained by using of control (no urea application) and 60% water requirement. Results showed that biopolymer coated urea is potent to improve some morphological characteristics and increase grain yield of sweet corn.