Journal of Biology and Nature

Tillering is a pivotal growth stage in rice that influences yield formation. Deep understanding of the relationship between tillering dynamics and yield formation in a particular agro ecosystem is crucial to escalating rice productivity. To find the optimum age of seedlings and characterize the contribution of cultivar tillering ability as affected by seedling age on tillering pattern, dry matter accumulation, yield components, and grain yield. The field experiments were conducted over 2-year period (2019 and 2020) using a split-plot design. Six cultivars were chosen, to represent moderate to high tillering abilities, and four different seedling ages were chosen (15, 25, 30 and 35 days), to produce differential tillering dynamics. The results revealed that both the cultivars and seedling age significantly affected the tillering pattern, phenological, dry matter production and yield contributing characteristics of modern transplanted Aman rice. In the initial stages, the treatments did not show any significant effect. At all the growth stages 15 days old seedlings of different cultivars showed maximum tillering. Older seedlings reduced the number of tillers m^-2 and increased the tiller mortality. Tiller mortality reached a peak between panicle initiation (PI) and booting (BT) stages. Leaf area (cm) significantly differs among different cultivars but not by seedling age. Total dry matter production gradually increased from maximum tillering to the maturity stage in all varieties. The number of panicles was positively related to the maximum number of tillers and grain yield. Total number of tillers at harvest had the biggest direct effect on grain yield. But in all the cases transplanting with younger seedlings (15 days) in a hill did not show significantly higher grain yield. These findings suggest that farmers may use 25-day-old rice seedlings to achieve more yield during T. Aman season in Bangladesh.