Abstract

Yields of traditional rice cultivars are typically low. The objective of this study was to understand the yield and agronomically important phenotypic traits of some traditional rice cultivars with different days to maturity at fertilized conditions. A field experiment was done at Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka during Maha 2011 to 2012 and Yala seasons in 2012. The recommended fertilizer dose for improved rice cultivars was applied for the study.  Effect of fertilizer on agronomic characters namely plant height (cm), number of tillers/plant and number of leaves/plant were measured during the experiment. Grain yield (g/plant) and harvest index were calculated at the end of the experiment. All the evaluated parameters were significantly higher at the fertilized conditions than those of at non fertilized conditions except the plant height in 161 to 165 days to maturity age group and number of leaves/plant in 110 to 115 days to maturity age group. At fertilized conditions the lowest significant plant height (97.5 cm) was recorded in the 161 to 165 age group while 151 to 155 age group recorded the significantly highest plant height (138.4 cm). The number of tillers/plant ranged from 6.0 to 9.8 while the highest significant number of tillers/plant (9.8) was recorded in 110 to 115 age group. However the highest grain yield/ plant (23.0 g) was recorded in the shortest days to maturity age group (110-115). Supporting this, the highest average yield/plant (10.1 g) at non fertilized conditions was also recorded in early maturing cultivars belong to 110 to 115 days to maturity age group.

Key words: Agronomic characters, traditional rice, fertilizer effect, days to maturity.