This seminar paper is
exclusively a review paper so that all of the information has been collected
from the secondary sources. During the preparation of this review paper, I went
through various relevant books, journals, proceedings, reports, publications,
thesis papers etc. Findings related to my topic have been reviewed with the
help of the library facilities of Bangabandhu Sheikh Mujibur Rahman
Agricultural University (BSMRAU), Bangladesh Agricultural University (BAU),
Bangladesh Agricultural Research Institute (BARI), Bangladesh Rice Research
Institute (BRRI) and Bangladesh Agricultural Research Council (BARC). I got
suggestion and valuable information from my major professor, research
supervisor and other research personnel. After collecting all the available
information, the researcher himself compiled those collected information and
prepared this seminar paper.
