| dc.description | Maize (Zea mays L.) is the only member of the genus Zea, of tribe maydeae under
the family Gramineae. It is originated from subtropical regions, probably from the
highlands of Mexico (Wilkes, 1979).
Maize is one of the most important principal crops of the world. It ranks third,
following wheat and rice in the world production of cereal crops. Maize yield is
higher than other cereals. Higher yield of maize over other cereals is due to its
high response to better crop management originating from its superior
physiological efficiency (Islam and Kaul, 1986). It is a C4 plant and that is why it
has high production potential for high photosynthetic capacity (Goldworthy,
1984).
Maize uses nutrients more efficiently due to its deep rooting system and it is more
tolerant to drought than rice and wheat. This allows maize to grow well under low
moisture conditions where rice or wheat may not grow so well. Moreover, maize
uses available moisture to produce dry matter more efficiently than rice or wheat
(Chrispcels and Sadara, 1997; House, 1985). | en_US |
| dc.description.abstract | In a laboratory experiment seeds of four maize varieties viz., BARI hybrid maize -5,
BARI hybrid maize -2, BARI maize -7 and BARI maize -5 were germinated at 24, 30
and 36°C to study seed metabolic activity and seed reserve translocation. All of the four
varieties were tested in the research field under well watered and non-irrigated water
stress condition by seeding at 20 November, 2007 to evaluate the morpho-physiological
changes in relation to water stress condition. Temperature had significant effect on
germination characteristics and seed reserves mobilization. At moderate temperature
(30°C) all the varieties showed highest seed metabolic efficiency (SME) than those of at
24 and 36°C temperature and hybrid varieties BARI hybrid maize -2 and BARI hybrid
maize -5 attained higher SME than the BARI maize -5 and BARI maize -7. In
phenology, the number of days for attaining different growth stages was affected by the
interaction of growing conditions and varieties. In the non-irrigated water stress
condition for all the varieties the number of days for attaining their seedling emergence,
four-leaf stage, eight-leaf stage, twelve-leaf stage, tassel emergence stage, silking stage
and maturity stage were higher than the well watered condition. The hybrid varieties
required higher number of days for attaining those phenological stages compared to other
varieties in both the growing conditions. Under well watered condition, all the varieties
showed higher relative leaf water content (RLWC) and moisture retention capacity
(MRC) compared to non-irrigated water stress condition. The combine effects of
growing conditions (water level) and maize varieties differed significantly the number of
green leaf at dry silk stage. length of leaf blade, length of leaf sheath, length of tassel,
plant height, number of cob per plant, cob length, cob diameter, number of row per cob,
grains per cob, single cob weight, weight of seed per cob, 100 seed weight, and grain
yield. From the overall result it was observed that two hybrid varieties (BARI hybrid
maize -2 and BARI hybrid maize -5) showed better performance in those physiomorphological traits compared to other varieties (BARI maize -5 and BARI maize -7) in
both the growing conditions. Finally, from the drought susceptibility index (S) it might
be concluded that BARI hybrid -2 and BARI hybrid maize -5 were comparatively
drought tolerant (S<1) than the other varieties (BARI maize -5 and BARI maize -7). | en_US |
