CHAPTER I

INTRODUCTION

Rice (dhan) is a cereal food plant Oryza sativa, of the grass family Gramineae,

extensively cultivated in worm climates, especially in East Asia, producing seeds

that are cooked and used as food. The word Ouliz of the Ningpo dialect of old

Chinese language became Oruz in Arabic and Oryza in Greek Language which

were changed to Ritz and Rice. Origin of the words dhan, dhanya is not known.

This crop has a wider adaptability and grows from sea level to a cultivation of

about 2600 metre (Jumla, Nepal). About 90 percent of the population of

Bangladesh is rice eaters. The Food Department of the Government of

Bangladesh recommends 410 gms of rice /head/day. Rice is the rich in

carbohydrates. The protein content is about 8.5 percent. Rice does not have C

and A vitamins. The Thiamin and Riboflavin contents are 0.27 and 0.12

micrograms respectively.

In Bangladesh total cultivable land is 90,98,460 hectare and near about 70 per

cent of this land is occupied by Rice cultivation. In the year of 2011, total

production of Rice is 3,35,41,099 metric ton. Hybrid rice varieties is cultivated

in 6,53,000 hectare of land and total production is 28,82,000 metric ton in the

year of 2010-2011. On the other hand, HYV (High Yielding Variety) is

cultivated in 40,67,000 hectare land and the total production of rice is

156,32,000 metric ton. The average rice production of hybrid varieties is 4.41

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metric ton and HYV varieties are 3.84 metric ton in the year of 2010 –

2011(BBS, 2011).

Rice (Oryza sativa L.) is an important staple food of more than half of the world

population. It is dominantly produced and consumed in the Asia. Since the

beginning of civilization, thousands of rice cultivars have been selected for

increasing productivity (Singh et al., 2000). Manipulation of genetic resources

has contributed much towards meeting rising demands of food for ever

escalating world population. In late 1960s“Green revolution” boosted yield of

cereal cropsincluding rice by the utilization of high yielding shortstatured

varieties with high sink capacity. The impact of green revolution is diminishing

due to rising demands of food commodities. The area under rice cultivation is

same but population has become manifold. The options available are to enhance

yield of rice on per unit area basis (Cassman et al., 2003) and development of

rice cultivars with high yielding ability which can increase production (IRRI,

1993). Producing varieties having resistance against biotic and abiotic stress by

using conventional and modern biotechnology can increase rice yields to meet

world requirement (Khush, 2005). The varieties have different physiological and

morphological characteristics that contribute towards yield (Yang et al., 2007;

Yang and Hwa, 2008). Ashrafuzzaman et al. (2009) found variation in

morphological and yield components in different varieties of aromatic rice.

Yield of rice can be enhanced by improving fertilization, irrigation management

and good pest and disease control.

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Aromatic rice is known for its characteristic fragrance when cooked. This

constitutes a small but special group of rice, which is considered best in quality.

Aromatic varieties fetch higher price in rice market than the non-aromatic ones.

Cultivation of fine as well as aromatic rice has been gaining popularity in

Bangladesh over the recent years, because of its huge demand both for internal

consumption and export (Das & Baqui, 2000). Despite the generally favorable

agroclimatic conditions, area of aromatic rice is less than 2% of the national rice

acreage of Bangladesh. More than four thousand landraces of rice are adopted in

different parts of Bangladesh. Only some of these are unique for quality traits

including fineness, aroma, taste and protein contents (Kaul et al., 1982). Most of

high quality rice cultivars are low yielding (Shakeel et al., 2005). Locally

adapted varieties are Chiniatop, Kalizira and Kataribhog. BR34 and BR38 are

another two high valued rice varieties released by Bangladesh Rice Research

Institute (BRRI), having small grain and pleasant aroma. These varieties could

be exported after meeting local demand. Aromatic rice varieties have occupied

about 12.5% of the total transplant aman rice cultivation (BBS, 2005).

Production of aromatic rice in Bangladesh is becoming popular due to its high

prices and export potentiality (Dutta et al., 2002). It is also preferred by some

consumers despite their price and yield. Farmers’ net income was increased by

23% with the adoption of modern varieties (Shrestha et al., 2002). Information

on morpho-physiological characters plays a vital role in rice breeding. It is

essential to know the physiological behavior and genetic expression of the

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selective aromatic and modern rice cultivars for definite breeding objectives to

improve those cultivars. Identifying promising morpho-physiological traits

associated with quality and yield plays an important role in varietal development

programs. Development of rice cultivars with a high yielding ability is one of the

most fundamental approaches for dealing with the expected increase in the world

demand (IRRI, 1993). However, this research work has been designed to

evaluate the growth and yield performance of eleven popular aromatic rice

cultivars in Aman season. Under the above circumstances, the present

experiment was under taken with the following objectives:

1. To evaluate growth and yield performance of eleven aromatic rice

cultivars in Aman season

2. To compare the yield and yield attributes of the test aromatic rice

cultivars in Aman season.

3. To generate information on aromatic rice.