Abstract

                                Field experiments were conducted during Kharif and rabi seasons of 1990-91 at the Agricultural College and Research Institute, Tamil Nadu Agricultural University. Killikulam to study the performance of rice ratooning as influenced by varieties, nitrogen and cutting height. Four varieties viz., ADT 36. ASD 16. CO 37 and PMK 1. three nitrogen levels (75.100 and 125 kg/ha) and cutting heights of 20 and 30 cm were tested in a split plot design. In the main crop, ADT 36 recorded maximum grain yield, wherein the ratoon crop. CO 37 registered the highest grain yield (2.56 and 2.61 tha in kharif and rabi respectively) followed by PMK 1. Growth and yield attributes like plant height, productive tillers, grains per panicle, panicle length and days to maturity were influenced by varieties and nitrogen. Per day productivity was the highest (32.5 and 30.0 kg/ha in kharif and rabi respectively) for rice variety CO 37. Nitrogen applied at 125 kg/ha recorded higher yield attributes and grain yield in ratoon rice. Cutting height had no significant influence on ratoon rice. The cost benefit ratio was maximum for variety CO 37.

Key words : Rice, ratoon, variety, nitrogen, cutting height, yield, economics