| dc.description | Rice (Oryza sativa L.) is the staple food of Bangladesh where it’s production has
increased more than two times during the last 3 decades and reached more than 25
million tons in 2006-2007 (BBS, 2008). Rice production is needed to be increased from
3 tons ha’! to 5 tons ha-' in next 20 years for food security (Mahbub ef a/., 2001). The
majority of rice area is covered by aman (Autumn) rice comprising about 52.77% of the
total rice area of which transplanted aman rice cover 87.05% (BBS, 2003). Among the
various factors responsible for low rice production, weeds are considered to be as one of
the major limiting factors due to manifold harmful effects (Kalyanasundaram ef al.,
2006). Weeds uptake the available nutrients, compete with crops for water, light and
space. Weeds are the most competitors in their early growth stages than the later and
hence the growth of crops slows down and grain yield decreases (Jacob and Syriac,
2005).| To reduce the cost of rice production, it has been urgently needed to adopt
alternative method of weed control viz. mechanical weed control, biological weed control
and chemical weed control in combination with manual weeding. | en_US |
| dc.description.abstract | An experiment was carried out at the Agronomy Field Laboratory, Department of
Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur
during the aman season (July to December), 2011 to study the effect of planting methods
and herbicides on the yield and yield attributes of aman rice cv. BRRI dhan33. The
experiment was laid out in a split plotdesign with three replications accommodating
planting methods in main plot and weed control measures in sub ploy Twelve species of
weeds belonging to seven families prevailed in the experimental field were Echinochloa
colonum L., Marsilea crenata L., Monochoria hastata L., Scirpus mucronatus L.,
Alternanthera sessilis R.Br., Ludwigia prostrata L. and Eclipta prostrata L. The effect of
different planting methods and weed control measures on the weed density and weed dry
weight and the yield and yield attributes were significant. Among the weed control
measures application of pre-emergence herbicide (rifit) + one hand weeding at 42
DAS/DAT had the lowest weed density and weed dry weight. The highest weed density
and weed dry weight was obtained from control (no hand weeding +no herbicide)
treatment {7 he yield attributes were significantly influenced by planting methods and
weed control measures/The total tillers m~’, effective tillers m?, grains panicle”,
spikelets panicle’, 1000-grain weight (g), grain yield (t ha’'), straw yield (t ha’),
biological yield (t ha’'), harvest index (%) were significantly higher in direct seeding by
drum seeder than those of direct seeding by hand and transplanted rice. /The highest
number of total tillers m”, effective tillers m?, grains panicle”, spikelets panicle’, 1000-
grain weight, grain yield (3.55 t ha’), straw yield, biological yield were found when the
test crop was weeded by application of pre-emergence herbicide(rifit) application + one
hand weeding at 42 DAS/DAT/The treatment of control (no hand weeding + no
herbicide) performed the lowest (1.933 t grain ha’'). In direct seeding by drum seeder,
crop duration was shortened by 12 days compared to transplanting method. The relative
profitability of direct seeding by drum seeder planted rice was Tk. 46257.9 ha’ over the
transplanted rice because of higher grain yield in the former case. Direct seeding by
drum seeder planted rice with application of pre-emergence herbicide (rifit) application +
one hand weeding at 42 DAS/DAT appears to be a promising technology in controlling
weeds in aman rice in aman season (cv. BRRI dhan33) and may be adopted in our
country. | en_US |
