| dc.description | Agriculture in Bangladesh is predominantly rice based and Bangladesh is the
fourth rice producing country in the world. It is grown in 6.46 million hectares of
land with a total production of 12.55 million tons in the year 2005-2006. Although
rice is the staple food of her people, the average rice production is 1.94 t ha”
(Anonymous 2006), which is very poor compared to other advanced rice growing
countries like South Korea, Spain, Australia, China and Japan where the average
yield is more than 5 t ha’ (Anonymous 1993). Bangladesh lacks arable land to
extend rice production. Besides, rice production is decreasing day by day due to
high population pressure, continuing drought and flood in farming areas, and
conversion of farmlands to grow cash crops instead of rice. Because of these
problems, the price of rice raised up to 49 to 60 percent in recent year
(Anonymous 2008). Therefore, it is an urgent need of the time to increase rice
yield in Bangladesh. The reasons for low yield of rice are manifold; some are
varietals, others are technological and rests are climatic. Undoubtedly, with the
introduction of high yielding varieties the yield of rice has been increased, but the
trend of increase is not linear. The yield can be increased using improved cultural
practices like use of quality seed, high yielding varieties, adopting plant protection
measures, optimum seedling age, optimum number of seedling hill’, seedling
raising technique, judicious application of fertilizers, etc. Among the improved
cultural practices, seedling age is an important factor as it has a tremendous
influence on the tiller production, grain formation and other yield contributing | en_US |
| dc.description.abstract | A field experiment was conducted at the research farm of Crop Physiology and
Ecology Department, Hajee Mohammad Danesh Science and Technology
University (HSTU), Dinajpur during June 2011 to October 2011 to find out the
effect of seedling age and rice varieties on tillering behavior, growth dynamics
and yield characters of rice in aman season. The experiment was laid out in a two
factors randomized complete block design with three replications taking four
seedling age (direct seeding, 15,25 and 35 days old at transplanting) and two rice
varieties (BINA -7 and BRRIdhan 49) as the factors. The result indicates tillering
behavior and dry matter accumulation of rice were significantly influenced by the
interaction effect of seedling age and varieties at different days after transplanting.
Rice varieties when seeded directly or transplanted with 25 days old seedling
provided greater number of tiller hill’ both at 50 days after transplanting and at
harvest. They also provided greater number of panicles hill at harvest in these
treatment combinations. Direct seeding of BINA-7 showed significant increase in
dry matter production than transplanting of rice seedling of different age at 50
days after transplanting but BRRIdhan 49 did not show such increment in dry
matter production in direct seeding. However BRRIdhan49 provided greater dry
matter accumulation when transplanied with 35 and 25 days old seedling. BINA -
7 when seeded directly or transplanted with 25 days old seedling and BRRIdhan
49 transplanted with 25 days old seedling provided greater leaf area index. BINA7 when seeded directly in the main field and transplanted with 25 days old
seedling provided higher grain yield whereas BRRIdhan 49 transplanted with 25
days old seedling provided greater grain yield than other seedling ages. BRRIdhan
49 took longer time to become harvest maturity stage than BINA-7 in all seedling
age in general. Moreover, with the increment of seedling age at transplanting,
duration of crop was found to be increased in both rice varieties. From the overall
results it could be concluded that different rice varieties showed different growth
pattern when seeded directly or transplanted with seedlings of different age
particularly in tillering behavior, dry matter accumulation and grain yield. | en_US |
